Home Page       Exam Question Downloads    Download TesTTaker Software    Free Sample Downloads   Maritime Links     Member Comments      Contact SeaSources  Boat Jobs Available

Click Here to Register and Begin Preparing For Your Exam with SeaSources Online Study.

TThis page is just a preview of the new Coast Guard question database. To test yourself on these questions click on the big blue link above.

Click here to see detailed video instructions on using SeaSources.net online license preparation.

New Motor Plants I Questions from 25 Sept 2012


1

A 16 cylinder main propulsion diesel engine is operating at 95% of full load. No. 7 cylinder is in alarm condition and indicating 1000F exhaust temperature. All fuel racks are at 21-22 mm except No. 7 which is at 18mm. A new fuel injector nozzle for No. 7 cylinder had been recently installed. Which of the listed actions should be carried out NEXT?

Take compression pressure readings on No. 7 cylinder.

Pull No. 7 cylinder piston and examine the rings.

Examine the governor linkage for binding.

Check the intake manifold pressure for evidence of burned intake valves.

2

A 18 cylinder medium speed direct reversible main propulsion diesel engine is being operated with one cylinder secured. When the engine was stopped, the affected cylinder stopped in a position preventing the engine from being restarted. Which of the following actions should be taken to correct the situation?

Turn the shaft with the turning gear while applying starting air.

Increase starting air pressure by small amounts until the air pressure is high enough to crank the engine over.

Admit starting air in the opposite direction to reposition the engine crankshaft and then restart in the desired direction.

Open the indicator cocks on those cylinders on compression and apply increased starting air pressure.

3

A 4 stroke, medium speed, eight cylinder, in-line diesel engine has a firing order of 1-5-2-6-8-4-7-3. When performing routine valve maintenance, #1 cylinder is set at TDC in firing position. Which exhaust valves can be checked for proper valve lash?

#1, #5, #2, #6

#1, #5, #2, #4

#1, #3, #2, #7

#1, #3, #2, #8

4

A bendy drive starting motor disengages the drive gear from the flywheel by .

spring force

rotating of the starting cam

having the flywheel impart a torque to the starter pinion

applying accumulator pressure

5

A 'Blotter test' is a test performed on the lube oil of a diesel engine which can determine .

the specific gravity of the oil

the flash point of the oil

a change in the oils viscosity

the TBN number of the oil

6

A bright shiny appearance of the sealing surfaces on diesel engine compression rings indicates .

combustion gas blow-by

excessive lubrication

properly functioning rings

insufficient cylinder cooling

7

A broken pintle in a fuel injector usually causes .

corrosion of the spray nozzle

clogging of the orifices

distortion of the spray pattern

erosion of the valves

8

A bronze bearing liner with a lead-tin flashing has a milky- white color over most of its surface and some areas of exposed bronze. The white coloring indicates .

proper break-in wear

improper break-in wear

relocation of the overlay flashing

water contamination of the lube oil system

9

A centrifuge will satisfactorily remove which of the following contaminants from fuel oil?

Gasoline

Water

Lubricating oil

Sulphur compounds

10

A change in the degree of fuel atomization in a diesel engine cylinder has the greatest effect on the .

cylinder air turbulence

fuel spray angle

fuel injection rate

combustion in that cylinder

11

A change in the degree of fuel atomization in a diesel engine greatly affects the .

air turbulence

fuel penetration

fuel spray tip angle

fuel injection rate

12

A change in the degree of fuel atomization in a diesel engine would most greatly affect .

air turbulence

fuel penetration

fuel spray angle

fuel injection rate

13

A change in the quality of fuel atomization by a diesel engine fuel injector would be caused by a/an .

increase in engine speed

increase in cylinder turbulence

leaking needle valve

reduction in cylinder turbulence

14

A characteristic of a bearing material which permits small dirt particles to become embedded in the bearing surface is .

desirable, as it will minimize damage to the journal surface

desirable, as it will assist in keeping the lube oil filters clean

undesirable, since the embedded particles will score the journal

undesirable, since the particles will interfere with lube oil flow

15

A closed freshwater cooling system is commonly used with marine diesel engines because the .

need for water treatment is eliminated

cooling water temperature differential is greater

cooling water pumps are directly reversible

jacket water temperature is more easily controlled

16

A common method for diesel engine piston cooling is to deliver oil through the connecting rod into a void space in the piston head and then allow the piston motion to distribute the oil to cool the piston crown and drain the oil back to the crankcase. This procedure is known as the .

splash method

spray method

shaker method

throw-off method

17

A condition contributing to diesel engine piston rings sticking in the ring grooves, is insufficient ring clearance at the ring .

gap

side

back

radial

18

A condition contributing to diesel engine piston rings sticking in the ring grooves, is insufficient ring clearance at the ring . I. Gap II. Side

I only

II only

both I and II

neither I nor II

19

A condition that can increase the foaming tendency of lube oil is .

excessively high oil temperatures

water or moisture contamination

fuel dilution

carbon suspension

20

A connecting rod in a four-stroke/cycle diesel engine is subject to .

tension load twice each crankshaft revolution

compression load during power and compression strokes

inertia load once every four crankshaft revolutions

bending loads at bottom and top dead center

21

A crack in a cylinder liner can be caused by .

worn piston rings

installation of undersized sealing rings

operating the engine at low loads

restricted cooling water passages

22

A cracked cylinder head in an operating engine may be indicated by .

a steady flow of water from the expansion tank vent

combustion gases venting at the expansion tank

lower temperature at the cylinder head water discharge

water draining from the fuel leak off lines

23

A cracked cylinder head on a diesel engine may be indicated by .

excessive lube oil consumption

water draining from the fuel leak off valves

combustion gases venting at the expansion tank

excessive fuel oil consumption

24

A crankshaft whose center of gravity coincides with its center line is said to be .

dynamically balanced

statically balanced

counter balanced

resonantly balanced

25

A crankshaft whose center of gravity coincides with its center line is said to be . I. statically balanced II. dynamically balanced

I only

II only

both I and II

neither I nor II

26

A decrease in the flash point of diesel engine lube oil indicates the lube oil has become .

contaminated with sludge

contaminated with carbon

diluted with fuel oil

diluted with water

27

A decrease in the flash point of the diesel engine lube oil indicates the lube oil is .

diluted with fuel oil

diluted with water

contaminated with carbon

contaminated with sludge

28

A defective injector nozzle in a propulsion diesel engine can cause .

engine power losses

smoking due to unburned fuel

high exhaust temperature readings

all of the above

29

A 'detergent-type' lube oil, used in a diesel engine, should be replaced when .

fuel oil dilution is 5%

it begins to turn black

the exhaust shows traces of blue smoke

all of the above

30

A device which functions to bring a diesel engine to a full stop to protect it from damage is known as a/an .

torque limiter

overspeed trip

overspeed governor

load limit governor

31

A diesel engine cooling water system with a pH factor of 3.0 indicates a condition of .

slight acidity

slight alkalinity

excessive alkalinity

excessive acidity

32

A diesel engine could fail to start because of .

incorrect injection timing

low exhaust back pressure

floating exhaust valves

excessive cranking speed

33

A diesel engine crankcase ventilation system .

prevents spark generation

removes combustible gases

determines the level of combustible gases

provides inert gas generation in crankcase

34

A diesel engine cranks properly during starting but immediately stalls. Which of the following systems is most likely at fault?

Hydraulic starting

Electric starting

Ignition

Fuel

35

A diesel engine cylinder has a swept volume of 104 cubic inches and a clearance volume of 8 cubic inches at top dead center. What is the compression ratio of the engine cylinder?

14.0 : 1

14.5 : 1

15.0 : 1

15.5 : 1

36

A diesel engine cylinder has a swept volume of 125 cubic inches and a clearance volume of 10 cubic inches at top dead center. What is the compression ratio of the engine cylinder?

12.5 : 1

13.5 : 1

14.5 : 1

15.5 : 1

37

A diesel engine cylinder has a swept volume of 125 cubic inches and a compression ratio of 13.5 to 1. What is the clearance volume in the cylinder at top dead center?

10 cubic inches

12.5 cubic inches

13.5 cubic inches

14 cubic inches

38

A diesel engine cylinder has a swept volume of 130.5 cubic inches and a clearance volume of 9.0 cubic inches at top dead center. What is the compression ratio of the engine cylinder?

12.5 : 1

13.5 : 1

14.5 : 1

15.5 : 1

39

A diesel engine cylinder has a swept volume of 135 cubic inches and a clearance volume of 10 cubic inches at top dead center. What is the compression ratio of the engine cylinder?

12.5 : 1

13.5 : 1

14.5 : 1

15.5 : 1

40

A diesel engine cylinder head can crack as a result of .

a leaking oil control ring

heat transfer from exhaust valves

restricted cooling passages

overheated intake valves

41

A diesel engine electric starting motor is operated under a no-load condition. Continuing to operate the motor unloaded will .

disengage the throw out bearing

overspeed and cause serious damage

fail to develop normal speed

cause the pinion to fail

42

A diesel engine exposed to widely varying ambient temperatures should use a lubricating oil with .

a high viscosity index

a low viscosity index

extreme pressure additives

no additives

43

A diesel engine fails to start because of water in the fuel. In order to start the engine, you should .

turn engine with jacking gear

drain filters and strainers and bleed off water at each injection pump

use ether to start the engine with blow down valves open

blow through the cylinders and fuel lines with a drying agent

44

A diesel engine fails to start due to excessive water in the fuel. Before the engine can be started, the water should be removed from the .

fuel lines

lube oil filter

crank case pump

rocker arm reservoir

45

A diesel engine fails to start, even though it can be barred over, but not cranked over. The probable cause is .

a seized piston

an improperly fitted bearing

a closed or obstructed air starting line valve

insufficient compression

46

A diesel engine indicator diagram has an area of 22 cm2 and a length of 12.5 cm. If the scale of the indicator spring is 1 mm = 1 kg/cm2, what is the cylinder mean effective pressure?

17.6 kg/cm2

27.5 kg/cm2

34.5 kg/cm2

36.0 kg/cm2

47

A diesel engine indicator diagram measures 12.5 cm in length and has an area of 22 cm2. What is the cylinder mean effective pressure if the spring used has a scale of 1.25 mm equals 1 kg/cm2?

14.08 kg/cm2

22.0 kg/cm2

34.5 kg/cm2

35.75 kg/cm2

48

A diesel engine is driving an alternator required to run at 1800 RPM. The overspeed governor is normally required to be set within a range of .

1980 to 2070 RPM

2100 to 2200 RPM

2200 to 2300 RPM

2300 to 2400 RPM

49

A diesel engine is equipped with the overspeed trip assembly shown in the illustration. At the inspection, the counter weight was found to be tripping out at too high of an RPM. The adjustment to lower the tripping speed RPM was carried out by .

decreasing the compression on spring #12

increasing the compression on spring #12

changing piece #10 to a lighter weight

reducing the counterweight pivot point friction

50

A diesel engine is provided with an overspeed throw-out weight shown in the illustration, and is tripping out at too low an RPM. In order to correct this problem, you should .

replace piece #10

decrease compression on spring #12

increase compression on spring #12

increase tension on lock wire by adjusting pieces #31, #32 and #35

51

A diesel engine is turned at normal cranking speed and no ignition occurs. This could be the result of .

low lube oil temperature

low starting air temperature

air bubbles in the fuel oil system

water in the starting air system

52

A diesel engine is turned at normal cranking speed, but fails to fire. This can occur from .

low lube oil temperature

low starting air temperature

air in the fuel injection system

water in the starting air system

53

A diesel engine may fail to start when being cranked, due to .

high cetane number

insufficient compression

low lube oil viscosity

high lube oil pressure

54

A diesel engine operating at a light load, when compared to operating at heavy load has an air/fuel ratio that is .

higher

lower

equal

directly proportional

55

A diesel engine piston crown can crack from .

excessive piston to liner clearance

excessive dirt beneath the piston crown that reduces heat transfer.

faulty nozzle spray

all of the above

56

A diesel engine piston ring face is in direct contact with the .

top of the ring groove

cylinder liner oil film

bottom of the ring groove

back of the ring groove

57

A diesel engine should use which type of lubricating oil?

Low viscosity

Cutting oil

High grade vegetable oil

Detergent oil

58

A diesel engine using lube oil with too high a viscosity will exhibit .

increased starting difficulty in cold weather

increased oil consumption

thickening at higher operating temperatures

minimal friction losses

59

A diesel engine which is rated for normal operation at a crankshaft speed of 800 RPM, is commonly classed as a .

slow-speed diesel

medium-speed diesel

high-speed diesel

constant-speed diesel

60

A diesel engine will lose power if fuel injection occurs too early because the .

fuel will not be properly atomized in the cylinder

ignition will be delayed due to low ignition temperature

maximum fuel expansion will occur on the compression stroke

fuel will ignite before top dead center

61

A diesel engine will lose power if fuel injection occurs too late in the cycle, because the .

fuel droplets will burn as they leave the fuel injector

fuel will not be properly atomized in the cylinder

maximum expansion of the burned fuel cannot take place in the cylinder

compression pressure will be too low to cause fuel ignition

62

A diesel engine with a combustion chamber located between the crowns of two pistons is known as a/an .

double-acting engine

opposed piston engine

single-acting engine

horizontal acting engine

63

A dirty diesel engine oil filter element can best be detected by .

visual inspection of the elements

the pressure drop across the filter

high lube oil sump temperature

decrease in oil viscosity from the filter

64

A dirty fuel oil filter can be detected by . I. fuel oil analysis II. observing the pressure drop across the filter

I only

II only

either I or II

neither I nor II

65

A dirty fuel oil filter element can be detected by .

visual inspection of the element

the pressure drop across the filter

high fuel oil tank temperature

increase flow rate from the filter

66

A dirty lube oil strainer can result in .

crankcase dilution

low lube oil temperature

excessive oil consumption

low bearing oil pressure

67

A disadvantage of a four-stroke/cycle over a two- stroke/cycle diesel engine is .

higher working temperature of piston and cylinder

the required use of scavenging ports

greater weight per horsepower ratio

intake valve temperatures higher than exhaust valve temperatures

68

A disadvantage of a two-stroke/cycle diesel engine is .

more power strokes per revolution

the use of scavenge air

more complicated valve gear

higher working temperatures of the piston and cylinder

69

A distorted spray pattern from a fuel injector can cause .

high firing pressure

corrosion of the nozzle tip

low fuel pressure

loss of power

70

A distorted spray pattern from a fuel injector can cause a diesel engine to have .

higher firing pressure

more power output

lower fuel pressure

less power output

71

A drop in compression pressure in one cylinder of a diesel engine can be caused by .

a leaking fuel injection nozzle

a clogged air filter

early fuel injection

burned valves

72

A faulty injector in one cylinder of an operating diesel engine can be located by .

cutting out individual injectors and noting engine performance

checking lube oil temperature

checking cam position

using a timing light

73

A faulty thermostatic bypass valve, in a diesel engine cooling system, can result in .

excessive time required for warming- up

excessive freshwater corrosion

scale formation on the saltwater side

saltwater mixing with the freshwater

74

A four cylinder, four stroke/cycle, single acting diesel engine has a 740 mm bore and a 1500 mm stroke. What indicated power will be developed if the average mean effective pressure is 18 kg/cm2 at a speed of 90 RPM?

3416 kW

4644 kW

7296 kW

9290 kW

75

A four-cycle, medium speed, eight cylinder, in-line diesel engine has a firing order of 1-5-2-6-8-4-7-3. When checking exhaust valve lash with the crankshaft set with #8 piston at TDC in the firing position, which cylinder exhaust valves can be checked for proper valve lash?

#8, #4, #7, #1

#8, #4, #7, #3

#8, #6, #7, #5

#8, #6, #7, #2

76

A four-stroke cycle main propulsion diesel engine fails to start at normal cranking speed with normal fuel pressure and ambient temperature. The reason for the failure could be .

glazed liners or pistons

high lube oil pressure

excessive compression ratio

excessive air leakage by rings and valves

77

A four-stroke eight cylinder in-line medium speed diesel engine has a firing order of 1-5-2-6-8-4-7-3. If #1 piston is at TDC and in the firing position, #4 piston is on .

the exhaust stroke

bottom dead center

the intake stroke

the compression stroke

78

A four-stroke eight cylinder in-line medium speed diesel engine has a firing order of 1-5-2-6-8-4-7-3. If #1 piston is at TDC and in the firing position, #6 piston is on .

the exhaust stroke

bottom dead center

the intake stroke

the compression stroke

79

A four-stroke eight cylinder in-line medium speed diesel engine has a firing order of 1-5-2-6-8-4-7-3. If #2 piston is at TDC and in the firing position, #3 piston is on .

the exhaust stroke

bottom dead center

the intake stroke

the compression stroke

80

A four-stroke eight cylinder in-line medium speed diesel engine has a firing order of 1-5-2-6-8-4-7-3. If #2 piston is at TDC and in the firing position, #4 piston is on .

the exhaust stroke

bottom dead center

the compression stroke

the intake stroke

81

A four-stroke eight cylinder in-line medium speed diesel engine has a firing order of 1-5-2-6-8-4-7-3. If #4 piston is at TDC and firing, how many degrees of camshaft rotation will occur when #5 piston reaches TDC and fires?

120 degrees

180 degrees

240 degrees

360 degrees

82

A four-stroke eight cylinder in-line medium speed diesel engine has a firing order of 1-5-2-6-8-4-7-3. If #4 piston is at TDC and firing, how many degrees of crankshaft rotation will occur when #5 piston reaches TDC and fires?

120 degrees

180 degrees

240 degrees

360 degrees

83

A four-stroke eight cylinder in-line medium speed diesel engine has a firing order of 1-5-2-6-8-4-7-3. If #8 piston is at TDC and firing, how many degrees of camshaft rotation will occur when #1 piston reaches TDC and fires?

120 degrees

180 degrees

240 degrees

360 degrees

84

A four-stroke six cylinder in-line diesel engine has a firing order of 1-5-3-6-2-4. When cylinder #2 is firing at top dead center, piston #1 is .

at top dead center

on the exhaust stroke

on the compression stroke

on the intake stroke

85

A four-stroke/cycle six cylinder in-line diesel engine has a firing order of 1-5-3-6-2-4. When cylinder #3 is firing at top dead center, piston #1 is .

at top dead center

on the exhaust stroke

on the compression stroke

on the intake stroke

86

A four-stroke/cycle six cylinder in-line diesel engine has a firing order of 1-5-3-6-2-4. When cylinder #6 is firing at top dead center, piston #4 is .

at top dead center

on the compression stroke

at bottom dead center

on the intake stroke

87

A fuel injection valve opening at a pressure lower than normal will result in .

late fuel injection

early fuel injection

high exhaust temperature from that cylinder

decreased effective stroke from that injector

88

A large low speed main propulsion diesel engine may become overloaded by . I. a heavily fouled hull II. strong head winds and heavy seas

I only

II only

both I and II

neither I nor II

89

A large two-stroke/cycle direct reversing diesel engine is to be reversed. Prior to the admission of starting air you must .

line up the engine for restarting with light diesel oil

reposition the fuel injection cam

change the intake and exhaust valve cam positions

reduce the main lube oil pressure

90

A large, low-speed, crosshead, main propulsion diesel engine using residual fuel oils must have a cylinder oil having a .

low TBN value

high alkaline reserve

low flash point

high pour point

91

A leaking diesel engine fuel injector will cause .

prolonged maintenance intervals

improved atomization

greater fuel economy

incomplete combustion

92

A 'low pressure in oil outlet' alarm indication, as shown in the illustration, may be caused by .

the proper setting of valve V4

insufficient heating of the processed liquid

the three-way valve (V1) not opening

insignificant accumulations of sludge within the bowl assembly

93

A magnetic strainer is primarily used in diesel engine reduction gear oil systems to remove small particles of .

copper

Babbitt

ferrous materials

acidic materials

94

A main propulsion diesel engine crankshaft bearing lacking sufficient 'crush', will .

pound under load

be lubricated more easily than with sufficient crush

tend to rotate with the journal

have a thicker layer of Babbitt

95

A main propulsion diesel engine is normally shut down by .

shutting off the air supply

overspeeding the engine

securing the fuel supply

securing the ignition system

96

A method of finishing diesel engine cylinder walls to aid in the proper ring seating and lubrication is known as .

ribbed honing

angled honing

cross hatch honing

doubled honing

97

A mixture of 45% cetane and 55% alpha-methyl- naphthalene is found to have the same ignition delay as a sample of diesel oil. The sample can be described as having a/an .

cetane number of 55

cetane number of 45

octane number of 55

octane number of 45

98

A modern centrifuge, similar to the device shown in the illustration, is opened for periodic cleaning. The most common cause of operating failure after reassembling, is due to .

low drive motor RPM

excessive back pressure in the bowl and fuel oil break over

the failure of the opening and closing water supply

not replacing the bowl O-rings that have taken a permanent set

99

A multi-orifice fuel injection nozzle is usually used with which of the listed types of combustion chamber?

Open combustion chamber

Precombustion chamber

Turbulence chamber

Energy cell

100

A naturally aspirated diesel engine operating at a light load, when compared to operating at heavy load, has an fuel/air ratio value that is .

higher

lower

equal

exponentially higher

101

A normal sludge ejection cycle will commence in the illustrated centrifuge when 'V5' is closed and .

'V10' and 'V15' are opened

V10' and' 'V15' are closed

V10' opened and 'V15' is closed

V10' closed and 'V15' is open

102

A normally operating diesel engine is shutdown by .

shutting off the air supply

overspeeding the engine

securing the fuel supply

securing the ignition system

103

A pilot-operated, main air starting valve begins leaking in one cylinder while the engine is operating. This malfunction is indicated by .

an increase in the exhaust temperature reading for that cylinder

an increase in the starting air manifold pressure

high exhaust pressure

an overheated air supply line to that cylinder

104

A piston in a four-stroke/cycle diesel engine makes four strokes during each .

crankshaft revolution

mechanical cycle of operation

period of two combustion cycles

cycle of two events

105

A piston is at bottom dead center when it is .

opening the exhaust ports

closing the fuel ports

farthest from the cylinder head

nearest to the cylinder head

106

A piston is said to be at top dead center when it is .

opening the exhaust ports

placed on top of the engine along its centerline

farthest from the cylinder head

nearest to the cylinder head

107

A piston is said to be at top dead center when it is .

opening the exhaust ports

closing the fuel ports

farthest from the cylinder head

nearest to the cylinder head

108

A plunger is used in the fuel injection pump shown in the illustration 'timed for port closing.' The injection process will always have a .

constant beginning and constant ending

variable beginning and variable ending

constant beginning and variable ending

variable beginning and constant ending

109

A port-and-helix fuel injection pump having upper and lower plunger helixes is designed to .

vary fuel delivery and return pressure

vary the beginning and ending of injection

operate with residual fuels only

provide maximum fuel delivery rate

110

A possible cause for an individual piston to knock when at TDC on a slow-speed, two-stroke/cycle main propulsion diesel engine could be due to .

early fuel injection

excessive bearing play within the running gear

overloading of the cylinder

all of the above

111

A practical way of checking for excessive fuel injection in one cylinder of an operating diesel engine is to .

feel the high pressure fuel line

check the cylinder exhausts for white smoke

frequently check the cylinder exhaust temperature

isolate each cylinder and inspect the injector

112

A properly honed diesel engine cylinder liner will .

prevent piston ring wear

shorten the ring break- in period

prevent cylinder liner glazing

appear slick and glazed

113

A properly honed diesel engine cylinder liner will .

prevent piston ring wear

shorten the ring break- in period

prevent cylinder liner glazing

appear mirror smooth

114

A safety crankcase cover differs from other diesel engine access doors in that it is fitted with a .

spring-loaded pressure plate

hand wheel

nut-operated clamp

large gasket

115

A scored diesel engine cylinder liner will cause .

high firing pressure

abnormally high cooling water temperature

rapid wearing of piston rings

combustion gases in the cooling water

116

A secondary function of diesel engine piston rings is to .

reduce friction losses in the engine

absorb the piston side thrust

prevent cylinder liner wear

prevent excess lubricant from reaching the combustion space

117

A seven cylinder, 2-stroke/cycle, single acting diesel engine has a 750 mm bore and a 2000 mm stroke. What indicated power will be developed if the average mean effective pressure is 14.8 kg/cm2 at a speed of 96 RPM?

1,959 kW

3,906 kW

14,363 kW

28,726 kW

118

A seven cylinder, two-stroke/cycle, single acting diesel engine with a cylinder indicated horsepower calculated as 1350 kW and brake horsepower measured at 7466 kW has a mechanical efficiency of .

18%

55%

79%

83%

119

A six cylinder 2-stroke/cycle, single acting diesel engine has a 580 mm bore and a 1700 mm stroke. What indicated power per cylinder will be developed if the average mean effective pressure is 15.3 kg/cm2 at a speed of 120 RPM?

1,366 kW

2,696 kW

4,044 kW

8,088 kW

120

A six cylinder, single acting, four-stroke/cycle diesel engine has a bore of 10 1/2 inches, and a stroke of one foot, producing 75 HP per cylinder at 720 RPM. What is the mean effective pressure in the engine cylinders for the stated conditions?

39.7 psig

79.4 psig

476.4 psig

952.7 psig

121

A six cylinder, two stroke/cycle diesel engine is 83% efficient and has a cylinder constant of 0.998 while operating with a mean effective pressure of 15 kg/cm2 at a speed of 100 RPM. What is the metric brake horse power developed?

5,559 mbhp

6,698 mbhp

7,455 mbhp

8,982 mbhp

122

A six-cylinder, four-stroke/cycle diesel engine is fitted with a rotary distributor type air starting system. The speed of the rotating distributor disc is .

one-half engine speed

the same as engine speed

twice engine speed

four times engine speed

123

A six-cylinder, two-stroke/cycle diesel engine is fitted with a rotary distributing air starting system. The speed of the rotating distributor disc is .

one-half engine speed

the same as engine speed

twice engine speed

four times engine speed

124

A spring-loaded relief valve is located on some lube oil filters in full flow systems to .

prevent over pressurization of the filter cartridge

prevent over pressurization of the filter casing

bypass the filter should it become clogged

limit the lube oil outlet pressure

125

A substantial increase in crankcase pressure could be an indication of .

excessive lube oil pressure

the proper seating of new rings

a worn cylinder liner

a malfunctioning cylinder relief valve

126

A substantial increase in crankcase pressure could be an indication of a/an .

worn cylinder liner

faulty cylinder relief valve

excessive lube oil pressure

excessive scavenge air pressure

127

A sudden decrease in the diesel engine lube oil viscosity could be an indication of .

loss of additives from the lube oil

carbon deposits in the lube oil

excessive centrifuging

excessive fuel dilution

128

A sudden drop in compression pressure in one cylinder of a diesel engine can be caused by .

a leaking fuel injector nozzle

a clogged air filter

excessively early fuel injection

malfunctioning valves

129

A three-way thermostatic control valve regulates the diesel engine cooling water temperature by passing a portion of the water .

around the engine

around the cooler

to the expansion tank

overboard

130

A turbocharged, eight cylinder, two-stroke/cycle diesel engine has a swept volume of 5160.31 cubic inches, a 9 1/16 inch bore, 10 inch stroke, and a compression ratio of 14.5 : 1. If during an overhaul, each cylinder head is to be trued by milling off .024 inches thereby losing 1.55 cubic inches from its clearance volume, what will be the resultant swept volume and new compression ratio?

5160.31 cubic inches; 14.92 : 1

5160.31 cubic inches; 14.95 : 1

5147.91 cubic inches; 14.92 : 1

5147.91 cubic inches; 14.95 : 1

131

A two stroke diesel engine exhaust temperature will be lower than a four stroke diesel engine of the same displacement because the . I. mep is lower and the scavenging air is cooling the exhaust gases II. valve overlap in a four stroke diesel engine is greater

I only is correct

II only is correct

both I and II are correct

Neither I or II are correct

132

A two stroke diesel engine exhaust temperature will be lower than a four stroke diesel engine of the same displacement because the . I. scavenging air is cooling the exhaust gases II. exhaust cycle time is longer

I only

II only

both I and II

neither I nor II

133

A two-stroke/cycle diesel engine requires less starting air than a four-stroke/cycle diesel engine, of equal displacement, because the two-stroke/cycle diesel engine .

has little or no internal friction

has a lower effective compression ratio

operates with scavenge air under a positive pressure

operates without energy absorbing intake and exhaust strokes

134

A unit type fuel injector is used on a diesel engine to .

meter the fuel

produce the proper fuel oil pressure

atomize the fuel

all of the above

135

A viscous damper, as used on a marine diesel, is a sealed precision built device which dampens the torsional vibrations in the .

camshaft

flywheel

crankshaft

thrust shaft

136

A visual inspection of the chrome plated piston compression rings at the liner ports reveals vertical brown streaks on the face of the rings. This condition indicates .

a broken ring

normal conditions

ring blow-by

a leaky fuel injector

137

A well-lubricated bearing surface always appears .

well knurled

slightly streaked

lightly glazed

highly polished

138

Abnormal crankpin bearing and piston skirt surface wear indicate .

a restricted air intake

a clogged connecting rod oil passage

incorrect connecting rod alignment

high cylinder firing temperatures

139

According to 46 CFR Part 56, isolation valves used in keel cooler installations may be constructed of .

bronze

copper

high temperature plastic

aluminum

140

According to Coast Guard regulations, keel cooler installations are .

required on all vessels of less than 150 gross tons

to be made between the bilge keel and the keel

to be provided with shutoff or isolation valves except when installed forward of the collision bulkhead

to be provided with expansion tanks, which must be located below the load line to provide positive cooling water flow

141

According to the chart shown in the illustration, which of the following statements is true concerning antifreeze solutions for diesel engine cooling systems?

A 100% ethylene glycol solution gives the greatest protection against freezing.

The boiling temperature of the solution remains constant at the level of greatest protection against freezing to -70F (-57C).

With antifreeze protection of -60F (- 51C), the boiling temperature could be 230F to 250F (110C to 121C).

A 30% solution of ethylene glycol will protect the cooling system at temperatures of -18F (-26C).

142

According to the diagram shown in the illustration, the lube oil system can best be described as a .

dry sump system

wet sump system

shunt system

bypass system

143

According to the illustrated polar timing diagram for a four- stroke cycle diesel engine, the exhaust valve is open for a duration of how many degrees of crank travel?

75 degrees

100 degrees

180 degrees

320 degrees

144

According to the illustrated polar timing diagram for a four- stroke cycle high speed diesel engine, the period of valve overlap occurs for a duration of how many degrees of crank travel?

75 degrees

125 degrees

160 degrees

320 degrees

145

According to the illustration, fuel cutoff timing in the cylinder is controlled with the component that is identified as the letter .

C

H

K

I

146

According to the illustration, fuel delivery to the cylinder is terminated and controlled with the component that is identified as the letter .

C

H

K

I

147

According to the illustration, fuel injection timing into the cylinder is controlled with the component that is identified as the letter .

C

H

K

I

148

According to the illustration, if water is ejected from an open indicator cock when the engine is rotated by the turning motor, a leak or crack may have developed at the .

injector seating surface

valve seat insert

upper portion of the cylinder liner

all of the above

149

According to the illustration, initial timing of fuel injection into the cylinder is controlled with the component that is identified as the letter .

C

H

K

I

150

According to the illustration, which of the following is true?

The piston has a replaceable crown.

The piston has five compression rings.

The piston has one oil scraper ring.

All of the above.

151

According to the illustration, which of the following is true?

The piston crown is non- replaceable.

The piston crown is designed with a heat dam.

The piston has one oil scraper ring.

All of the above.

152

According to the illustration, which of the following is true?

The shaker method is used for piston cooling.

The piston has four compression rings.

The piston has two oil scraper rings.

All of the above.

153

According to the illustration, which of the following statements is true concerning the operation of a large slow speed diesel engine?

Operating in the shaded area labeled "A" would result in the engine being overloaded.

Operating in the area labeled "B" would result in the engine being under-loaded.

Operating near or on the line labeled "P" would result in the greatest engine operating efficiency.

All of the above

154

After a long period of operation, a wear ridge, caused by piston ring action, will develop near the top of the cylinder liner. This ridge must be removed during maintenance in order to prevent .

excessive ring wear during the seating period

excessive lubrication of the top ring

improper coating of lubrication on the cylinder wall

breaking of the rings, ring lands, or both during piston removal

155

After an engine has been started using a Bendix drive unit, the drive pinion disengages from the flywheel due to .

the action of a spring

rotation of the starting cam

the flywheel applying torque to the starter motor drive pinion

accumulator pressure

156

After changing out the fuel filters the diesel engine fails to restart. The most probable cause for this condition is a/an .

low compression

air-bound fuel system

improper spark

change in viscosity

157

After following the prescribed procedures to measure the thrust bearing clearance shown in the illustration, the distance "F" is determined to be 200 mm, and 'f1' is 2.3 mm. Which of the following statements describes the condition indicated by these dimensions?

The total active thrust area is 202.3 mm, well within the standards set forth by the GSMA (German Society for Machining Accuracy).

The loading ratio, or shaft diameter divided by collar surface area is within 2.7 : 1.

These dimensions indicate the presence of flourishing marks on the thrust shoes; the marks becoming visible as the distance at 'f1' increases.

It is possible for the shaft to move axially 2.3 mm during astern operation and relates to an excess movement of 1.3 mm, 0.3 mm beyond the maximum worn play.

158

After removing an old set of rings, which of the following conditions is indicated if a bright spot is found on each end of a broken piston ring?

Improper lubrication

Excessive diametrical tension

Insufficient ring pressure

Insufficient gap clearance

159

After removing the bowl hood of the device shown in the illustration, excessive quantities of sludge are visible. Which of the following statements represents the approach to rectify the situation?

Disassemble the entire unit, clean all components, replace all defective discs and use the proper lubricant where required.

Steam clean the components in place, check for proper alignment, using the match marks provided, reassemble and restart the unit.

Remove only the disc stack, separate all the discs, clean with steel wool and solvent, replace the disc stack ensuring it is located by use of the dowel pin shown.

Disassemble the entire unit, clean all components, replace any defective gaskets and use the proper lubricants where required.

160

After starting a diesel engine, which of the listed operating conditions should be checked FIRST?

Air box pressure

Lube oil pressure

Exhaust temperatures

Raw water pressure

161

Air in the fuel can cause .

high lube oil temperature

blue smoke

the engine to stop

piston seizure

162

Air in the fuel lines of a diesel engine can cause .

ignition failure

oxygen corrosion of the fuel lines

the pistons to seize

blue smoke

163

Air in the fuel lines to the fuel injection nozzles of a diesel engine will cause the engine to .

burn excessive amounts of lube oil

overheat without smoking

operate with reduced power or stop

run away without load

164

Air in the fuel lines to the fuel injection nozzles of a diesel engine will result in .

lower compression pressures

overheating without smoking

failure to start

a run away without load

165

Air is normally bled from a diesel engine fuel system by .

blowing down the air tanks

loosening the compression nuts at the injectors

changing fuel filters

pumping down the day tanks

166

Air motion is induced in a four-stroke/cycle diesel engine cylinder to improve air fuel mixing, and is known as .

supercharging

scavenging

turbulence

swept volume charging

167

Air motors used for starting some auxiliary diesel engines are generally designed as .

vane type motors

plunger type motors

gear type motors

accumulator type motors

168

Air motors used for starting some auxiliary diesel engines are generally the type known as a/an .

vane motors

plunger motors

gear motors

accumulator motors

169

All alarms occurring on the control unit of the device shown in the illustration will .

not be indicated in numerical order

shut off the oil feed to the separator

cause the separator to automatically enter the sludge discharge cycle

be initiated by the water transducer or vibration switch

170

An acceptable means of tightening connecting rod and main bearing cap bolts is to measure the . I. torque applied to each nut and bolt assembly II. stretch of each bolt after tightening

I only

II only

both I and II

neither I nor II

171

An acceptable means of tightening connecting rod and main bearing cap bolts is to measure the . I. torque applied to each nut and bolt assembly II. stretch of each nut before and after tightening

I only

II only

both I and II

neither I nor II

172

An acceptable method for measuring the applied rotational force when tightening connecting rod and main bearing bolts, is to use a .

torque wrench

monkey wrench

pipe wrench

slugging wrench

173

An accumulator used in a hydraulic starting system is generally located between the .

pump and the compressor

storage tank and the pump

starting motor and the reserve tank

pump and the starting motor

174

An advantage of aluminum pistons, when compared to cast iron pistons is .

greater high temperature strength

better heat conductivity

greater weight per cubic inch

increased resistance to wear

175

An air starting motor for a diesel engine is protected from overspeeding by .

an electric solenoid interlock

a three-way automatic valve

an overrunning clutch

all of the above

176

An automated diesel engine should normally shut down due to .

low lube oil temperature

high ambient air temperature

low lube oil pressure

high exhaust system back pressure

177

An auxiliary diesel engine may fail to start due to .

low exhaust back pressure

high lube oil temperature

insufficient cranking speed

excessive fuel atomization

178

An auxiliary diesel generator continues to run after you try to shut down. Your next course of action should be to .

block the flow of air supply to the engine

engage the jacking gear

secure the lube oil pump

decrease control air pressure

179

An auxiliary diesel generator continues to run after you try to shut down. Your next course of action should be to .

block the flow of air supply to the engine

engage the jacking gear

secure the lube oil pump

decrease control air pressure

180

An efficient seal between the cylinder block and cylinder heads on many auxiliary diesel engines is obtained with .

graphite packing

sealing compound

lubricating oil

copper gaskets

181

An efficient seal between the cylinder block and cylinder heads on many diesel engines is obtained with .

graphite packing

sealing compound

lubricating oil

gaskets

182

An eight cylinder, air started, two-stroke/cycle, direct reversing, marine diesel engine can be rotated from any crankshaft position by the air start system only if it has .

each upper cylinder head equipped with reversible air start valves

a minimum of five cylinders equipped with air start valves

at least four cylinders equipped with air start valves

the cylinders on opposite ends equipped with air start valves

183

An eight cylinder, four stroke/cycle, single acting diesel engine has a 650 mm bore and a 1400 mm stroke. What will be the developed indicated metric horsepower if the average mean effective pressure is 30 kg/cm2 at a speed of 100 RPM?

1689 kW

9,111 kW

12,388 kW

24,776 kW

184

An eight cylinder, four stroke/cycle, single acting diesel engine has a 650 mm bore and a 1400 mm stroke. What will be the indicated power developed if the average mean effective pressure is 30 kg/cm2 at a speed of 100 RPM?

1689 kW

9,111 kW

12,388 kW

24,776 kW

185

An electric heater built into some smaller diesel engines is used to .

raise lube oil viscosity for easier starting in cold weather

increase air inlet temperature

increase compression ratio

increase jacket water temperature for easier starting in cold weather

186

An emergency diesel generator cooling system is equipped with an automotive type thermostat. If the thermostat bellows loses its charge, the thermostat will .

open, and the coolant temperature will increase

open, and the coolant temperature will decrease

close, and the engine coolant temperature will increase

close, and the coolant temperature will decrease

187

An emergency diesel generator should automatically shut down in the event of .

dangerous overspeeding

a loss of lube oil pressure

the activation of the fixed CO2 system for the emergency generator space

all of the above

188

An examination of the piston compression rings of an efficiently operating diesel engine, should appear with a .

shiny face and bottom, black back and top

shiny face, black top, back and bottom

shiny face, bottom, back and top

black face, bottom, back and top

189

An immediate repair is required if a leak occurs in the high pressure fuel piping between the injection pump and fuel nozzle because of the .

high cost of fuel

serious fire hazard

pollution hazard

poor combustion which will occur in that cylinder

190

An improperly assembled centrifuge, of the type shown in the illustration, may result in which of the following operating conditions to occur?

Excessive wear of fuel injection equipment.

Increased main bearing wear.

Severe injury to engine room personnel.

All of the above.

191

An incorrect spray pattern produced by a diesel engine fuel injection nozzle can be directly caused by .

incorrect fuel rack setting

overcooling of the nozzle

low firing pressure

excessive lube oil temperature

192

An increase in crankcase pressure generally indicates .

worn connecting rod bearings

worn engine cylinder liners

high cylinder operating temperature

stuck spring-loaded manhole covers

193

An increase in diesel engine crankcase pressure generally indicates excessive .

compression pressure

lube oil header pressure

scavenge air pressure

piston ring blow-by

194

An increase in the fuel injection pump discharge pressure can be caused by a/an .

leaking delivery valve

increase in engine load

plugged injector spray hole

increased plunger stroke

195

An increased pressure differential between the inlet and outlet of a strainer usually indicates the strainer is .

holed

fouled

clean

dry

196

An indication of an overloaded main propulsion diesel engine is .

white smoke in the exhaust

high exhaust gas pyrometer readings

sparks in the exhaust

blue smoke in the exhaust

197

An indicator card or pressure-volume diagram, shows graphically the .

compression ratio of the engine

volume of the engine

relationships between pressure and temperature during one stroke of the engine

relationships between pressure and volume during one cycle of the engine

198

An individual fuel injection pump is designed for variable beginning and constant ending of injection. For diesel engines operating a generator at constant speeds, the start of injection will .

advance as the load increases

retard as the load increases

remain unchanged regardless of load

always occur at top dead center

199

An oil-operated, direct-reversing mechanism on a large, low- speed, main propulsion diesel engine, can serve to .

bring the respective cam under the fuel pump roller

rotate or displace the camshaft according to engine design

bring the respective cam under the air distributor pilot valves

all of the above

200

An overspeed safety shutoff for a diesel engine is shown in the illustration. Which of the following movements will occur if the engine overspeeds?

Piece #8 will move up

Piece #8 will move down

Piece #10 will rotate counterclockwise

Piece #9 will move to the left

201

An overspeed trip serves to .

stop the engine by cutting off the cooling water supply

stop the engine by closing the air intake and/or fuel supply

slow the engine to idle speed

slow the engine to just below maximum speed

202

An overspeed trip stops a diesel engine when the engine .

runs out of fuel

has low lubricating oil pressure

exceeds a set maximum speed

has high cooling water temperature

203

Antifreeze solutions containing ethylene glycol, should not be mixed with corrosion protection oils, as the resultant mixture .

is dangerously flammable

promotes scale buildup

may cause frothing

has a higher chloride content

204

As a general rule, what would be the recommended operating water jacket outlet temperature range from the engine for medium speed marine diesels set up with closed treated fresh water cooling systems and fitted with vented expansion tanks?

105 to 120F

135 to 150F

165 to 180F

195 to 215F

205

As engine RPM is increased from idle speed to full load speed, which of the conditions listed will decrease?

Compression ratio

Air/Fuel ratio

Compression pressure

Lube oil pressure

206

As illustrated, what is the maximum allowable clearance permitted between the bearing and the shaft along its vertical axis?

1.00 mm

0.30 mm

0.46 mm

0.80 mm

207

As shown in the illustration of the fuel injection pump, the component labeled "C" would be identified as the .

Sleeve

Control Rack

Barrel

Plunger

208

As shown in the illustration of the fuel injection pump, the component labeled "J" would be identified as the .

Delivery check valve assembly

Control rack and pinion

Plunger and barrel spring

Control rack and sleeve

209

As shown in the illustration of the fuel injection pump, the component labeled "N" would be identified as the .

Sleeve

Control Rack

Barrel

Plunger

210

As shown in the illustration of the fuel injection pump, the function of the area designated as "G" is to .

control the fuel injection rate

lubricate the plunger

provide a fuel supply to the pump

relieve excessive injector discharge pressure

211

As shown in the illustration of the fuel injection pump, the function of the area designated as "L" is to .

control the fuel injection rate

allow excess fuel oil to return to the fuel oil system

provide for plunger lubrication

relieve excessive injector discharge pressure

212

As shown in the illustration of the fuel injection pump, the section designated as "M" is referred to as the .

plunger sleeve

plunger helix

plunger relief shoulder

plunger control tab

213

As shown in the illustration, engine piston cooling oil is supplied to the pistons by a/an .

oil spray

oil wick

oil control rings

drilled passage through the camshaft

214

As shown in the illustration, the alarm indicated by 'emergency stopping or vibrations' may be caused by .

the rotating action of the centrifugal switch

new foundation bolt assemblies and dampeners

a failure to reset the emergency stop button

the emulsification of water and fuel within the parting chamber

215

As shown in the illustration, the viscosimeter would be used to directly control the output of which of the following components?

Outflow from HFO day tank.

Final heaters.

Injector pumps.

HFO purifiers.

216

As shown in the illustration, which of the following conditions may be the cause for the 'low pressure in oil outlet' alarm to be illuminated?

Vibration switch activated.

Faulty water solenoid valve.

Throughput too high.

All of the above are correct.

217

As shown in the illustration, which of the following conditions would be responsible for a 'low pressure in oil outlet' alarm to be indicated?

Throughput too low

Separating temperature too low

Controller set point changed

Emergency stop button not reset

218

As shown in the illustration, which of the following conditions would be responsible for a 'low pressure in oil outlet' alarm indication?

Steam supply pressure low.

Separating temperature too high.

Throughput too high.

Regulating valve V4 is closed.

219

As shown in the illustration, which of the following conditions would cause the 'low pressure in oil outlet' alarm to be illuminated?

Throughput too low.

Separating temperature too high.

Line to pressure switch PS2 obstructed.

All of the above are correct.

220

As soon as a diesel engine has started, which of the listed engine operating parameters should be checked FIRST?

Exhaust temperatures

Raw water pressure

Lube oil pressure

Air box pressure

221

At bottom dead center, the centerline of the connecting rod usually coincides with the .

angularity of the piston motion

inertia moment from the piston

centerline of the cylinder

centerline of the king pin

222

At dead center, the centerline of the connecting rod usually coincides with the .

angularity of the piston motion

inertia moment from the piston

centerline of the cylinder

centerline of the king pin

223

At the end of a normal sludge ejection cycle, the bowl of the centrifuge, shown in the illustration, will be closed only when the valve(s) .

V5' is closed, with 'V10,' 'V15,' and 'V16' are open

V5,' 'V10,' 'V15,' and 'V16' are closed

'V10' and 'V16' are open, with 'V15' closed

V5,' 'V10,' 'V15,' and 'V16' are open

224

At top dead center, the centerline of the connecting rod usually coincides with the .

angularity of the piston motion

inertia moment from the piston

centerline of the cylinder

centerline of the king pin

225

Auxiliary diesel engine electric starting motors use .

alternating current transformers

400 cycle per second motor-generator power

low amperage, high voltage AC power

battery power direct current

226

Barrel face, taper face, grooved, and chrome plated are all types of diesel engine .

pistons

piston rings

piston skirts

cylinder liners

227

Bearing clearances in small high-speed diesel engines should be measured using .

gage blocks

plasti-gage

feeler gages

round solder wire

228

Bearing clearances in small high-speed diesel engines should be measured with .

gage blocks

plasti-gage

feeler gage

round solder wire

229

Bearing 'crush' as applied to diesel engine main bearings, will result in .

positive seating of the bearings in their housings

above normal operating temperatures

damage to the journals

damage to the bearings

230

Bearing wear on a split sleeve type bearing is normally measured with a .

ball anvil micrometer

pair of outside calipers and a dial indicator

pair of inside calipers

depth micrometer

231

Because of the close tolerances used in diesel engine fuel oil pumps, a worn plunger requires .

grinding the spare plunger to the barrel

replacing the plunger and the barrel

highly polishing both the plunger and barrel

replacing plunger only

232

Before any auxiliary diesel engine hydraulic starting system is opened for servicing or repair, you must .

place all control levers in the 'HOLD' position

ensure that the hydraulic fluid reservoir is full

block all hydraulic hoses using high pressure covers

bleed off all hydraulic pressure from the system

233

Before being shut down, a diesel engine should idle a few minutes in order to .

prevent governor surging at shutdown

make sure the fuel nozzles are flushed clean

prevent pressure buildup in the fuel lines

prevent damage from localized overheating

234

Before installing rings on a diesel engine piston, you should check the ring .

diametrical tension

gap clearance

radial thickness

outside diameter

235

Before shutting off the fuel supply to stop a medium or high- speed diesel engine, why is it necessary to allow the engine to idle for a few minutes?

To prevent internal damage from local overheating.

To ensure the fuel nozzles are flushed clean.

To clear the smoke stack.

To let the waste heat boiler reduce it's rate of steam generation.

236

Before shutting off the fuel supply to stop and secure a diesel engine, why is it necessary to allow the engine to idle for a few minutes?

To prevent internal damage from local overheating.

To ensure the fuel nozzles are flushed clean.

To clear the smoke stack.

To let the waste heat boiler reduce it's rate of steam generation.

237

Before starting a diesel engine that has an engine driven lube oil pump, the engineer should .

open the bypass line

cut in the lube oil cooler

pressurize the lube oil system with the prelube pump

top off the expansion tank

238

Before starting a diesel engine, you should always .

check the pyrometer readings

check the crankcase oil level

change the fuel oil strainers

clean the air filter

239

Before starting the device shown in the illustration, the operator should always check the .

bowl spindle nut

braking mechanism

pump drive coupling

auto restart switches

240

Besides the use of piston cooling fins to assist in cooling, they also provide extra strength for the piston .

skirt

crown

wrist pin

oil rings

241

Between the periods of injection and ignition of the fuel, a diesel engine crankshaft rotates through the .

detonation period

firing period

ignition delay period

ignition advance period

242

Black areas on the sealing surfaces of piston rings indicate .

lube oil pumping

rotating rings

gas pressure behind the ring

passage of hot gases

243

Brake specific fuel consumption is given in units of .

DEMA

lbs/bhp-hr

BTU/lb

PLAN

244

Burning fuel with a high sulfur content in a diesel engine will .

increase thermal efficiency

cause clogging of the fuel system

increase the ability of the engine to start in cold weather

produce corrosion in the cylinder and exhaust system at low loads

245

Cams used to activate mechanically operated air starting valves on four-stroke/cycle diesel engines should have which of the valve lift profiles listed?

Abrupt lift with a short open period, and abrupt valve seating.

Gradual lift with a short fully open period, and accelerated valve closing.

Abrupt lift giving full valve opening for a long period, with gradual valve seating.

Gradual lift giving full valve opening for a long period, with gradual valve seating.

246

Camshafts are usually driven by timing gears or .

push rods

chain drives

rocker arms

flywheels

247

Carbon deposit build up on the injection nozzle orifice is least likely to occur when using which type of fuel injector nozzle?

Hole

Multi-hole

Pintle

Multi-pintle

248

Cast iron pistons used in large propulsion diesel engines are constructed with .

no taper for the entire length

the skirt being tapered and smaller than the crown

the skirt being tapered and larger than the crown

the crown being tapered and smaller than the skirt

249

Cavitation erosion in the cooling water system of a diesel engine usually occurs at the pump impeller, and on the waterside of the .

fuel nozzle holders

exhaust valve guides

engine cylinder liners

engine exhaust manifold

250

Clogged diesel engine fuel oil filters can cause ,

loss of power

misfiring

low fuel oil pressure

All of the above

251

Cold clearances between the skirt of an aluminum piston and the cylinder liner is about .

twice as large as with a cast iron piston

the same size as with a cast iron piston

half as large as with a cast iron piston

the same size as the crown of an aluminum piston

252

Cold weather starting of a diesel engine is more difficult than warm weather starting due to .

use of low viscosity oil in cold weather

increased moisture content of inlet air in cold weather

increased drag of pistons and bearings due to increased oil viscosity

higher compression pressures reached due to smaller clearances existing in the engine during cold weather

253

Combustion gas venting through the expansion tank can be caused by a .

leaking oil cooler

cracked cylinder head

leaking exhaust valve

worn piston ring

254

Combustion gases formed in the cylinder of a diesel engine are prevented from blowing past the piston by .

cylinder valves

compression rings

piston skirts

oil rings

255

Combustion knock can occur in the cylinders of a diesel engine under any condition permitting .

a shortened ignition delay period

a lean fuel/air mixture

excess fuel in the combustion chamber

rapid vaporization of injected fuel droplets

256

Combustion knock occurring in a diesel engine can be caused by .

low coolant temperature

insufficient fuel

high ambient temperature

carbon buildup on the nozzle holder

257

Combustion knock occurring in a diesel engine can be caused by .

excessive fuel penetration

prolonged injection lag

reduced ignition lag

prolonged ignition lag

258

Combustion knock will most likely occur as a result of using a fuel with .

low ignition quality

a high volatility

low ignition delay

a high cetane number

259

Compared to four-stroke/cycle engines, two-stroke/cycle diesel engines have the disadvantage of .

less even torque

higher cylinder head temperatures

fewer power strokes per revolution

greater weight/size requirements

260

Compared to other fuel injection systems, unit injectors operate with virtually no .

injection lag

ignition delay

moving parts

requirement for timing adjustments

261

Component "F" shown in the illustration is called the .

camshaft adjusting screw

permadjust assembly

injector control shaft

cylinder head locking device

262

Component "U" of the diesel engine shown in the illustration is called the .

crankshaft counterweight

frequency tuner

main bearing support assembly

frame stiffener

263

Concerning the diesel engine shown in the illustration, which of the following represents the number of crank angle degrees of rotation existing between each firing? (See illustration MO-0038.)

60

120

180

240

264

Connecting rods in a diesel engine are used to connect the .

engine to the bed

rocker arm to the camshaft

crankshaft to the gear train

piston to the crankshaft

265

Coolant can be lost from a diesel engine jacket cooling water system by leakage from .

cylinder head cracks

piping joints

pump seals leaking

all of the above

266

Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type pump with a concentric housing to .

provide equal water flow capacity when the engine is running either ahead or astern

provide the greatest pump efficiency when running ahead

prevent pump clogging from marine growth

prevent cavitation at the pump outlet

267

Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type pump with a concentric housing to .

facilitate bi-directional operation

provide the greatest pump efficiency

prevent pump clogging from marine growth

prevent cavitation at the pump outlet

268

Cooling water pumps driven by direct-reversing diesel engines are usually .

curved impeller vane with tangential outlet

curved impeller vane with concentric outlet

straight impeller vane with concentric housing

straight impeller vane with tangential housing

269

Corrosion inhibitors and/or soluble oils are added to diesel engine cooling systems to .

maintain low pH in the cooling water

reduce the cooling water temperature

increase cooling water hardness

form a protective film on metal surfaces

270

Cracking of a diesel piston crown can result from .

early injection timing

the underside of the piston crown being excessively dirty, lowering the rate of heat transfer

faulty oil nozzle spray

all of the above

271

Crank web deflection readings will give a positive indication of .

worn main bearing journals

crankpin misalignment

slack thrust bearings

bearing shells shim dimensions

272

Crankcase explosions in propulsion diesel engines result from .

the splashing of lubrication oil by the crankshaft

the dilution of crankcase oil with particles of combustion

broken fuel lines spraying oil on the crankcase

the ignition of unburned fuel and air in the crankcase

273

Critical speed in diesel engines occurs when engine torque pulsations become .

opposed to the crankshaft rocking couple

resonant with the crankshaft natural frequency

critical fore and aft crankshaft vibrations

horizontal whipping motions of the crankshaft

274

Critical speeds occurring within the operating speed range of a main propulsion diesel engine may be changed, or have their damaging effects reduced by a/an .

engine support vibration isolator

detuner or viscous fluid damper

lightened crankshaft flywheel

spherically seated crankshaft bearing

275

Cylinder lubrication oil for low speed main propulsion diesel engines is admitted to each cylinder during .

the power stroke

the compression stroke

low load operation only

periods of standby

276

Device "E" shown in the illustration is known as the .

fuel manifold

lube oil manifold

overspeed trip shaft

extrusion tube assembly

277

Device '27' shown in the illustration is used to .

regulate maximum vacuum during normal operation

purge the unit of non- condensable gases

relieve excess pressure

add de-scaling chemicals as needed

278

Diesel engine air start system check valves are opened by .

an air start cam

cylinder compression pressure

starting air pressure

valve springs

279

Diesel engine air start valve timing is controlled by .

engine operating speed

an air manifold

a hydraulic distributor

individual cams and valve gear

280

Diesel engine 'blow-by' into the crankcase is caused by excessive ring .

back clearance

side clearance

gap clearance

taper clearance

281

Diesel engine blow-by is the leakage of combustion gases past the .

oil rings only

compression and scraper rings

cylinder liner sealings

cylinder liner ring grooves

282

Diesel engine crankshaft deflection readings are generally taken at four crank positions. Good engineering practice requires the deflection gage or indicator to be .

placed as near the crankpin axis as possible

removed each time the crankshaft is repositioned

left in place for all four readings

reset to zero for all four readings

283

Diesel engine cylinder head test cocks are used to .

check cylinder lubrication

connect the pressure indicator

pressure test cylinder heads

connect the exhaust gas pyrometers

284

Diesel engine cylinder head test cocks are used to .

check cylinder lubrication prior to starting engine

connect exhaust gas analyzers to determine engine efficiency

pressure test cylinder heads to check for leaks

remove moisture accumulations from cylinders prior to starting

285

Diesel engine electric starting motors generally require heavier duty motors and operate at higher voltages than comparable starting motors for gasoline engines due to .

higher speed required

flywheel effect

lower starting temperatures

higher compression pressures

286

Diesel engine fuel oil contamination often results in .

governor malfunctions

fuel injection system malfunctions

high cylinder lube oil temperatures

low intake temperatures

287

Diesel engine injection lag is caused by .

compressibility of the fuel

high fuel oil supply flow

low cylinder firing pressure

excessive air turbulence

288

Diesel engine injection lag is caused by .

compressibility of the fuel

high fuel oil supply flow

low cetane value of the fuel

excessive air turbulence

289

Diesel engine injection lag is caused by .

compressibility of the fuel

high fuel oil supply flow

low injector popping pressure

excessive air turbulence

290

Diesel engine injection lag is caused by .

compressibility of the fuel

high fuel oil temperature

low injector popping pressure

excessive air turbulence

291

Diesel engine jacket water is used in the fresh water distillation process as the .

coolant for the distillate

coolant for the brine cooler

means of heating the feed water

primary means of producing a vacuum within the distiller

292

Diesel engine lube oil can become contaminated as a result of .

the water produced during combustion

the sulfur in the fuel

unburned fuel oil

all of the above

293

Diesel engine lube oil diluted with diesel fuel oil is indicated by .

decreased viscosity

decreased pour point

increased flash point

increased viscosity

294

Diesel engine main and connecting rod precision bearings are made in halves. Each half exceeds one-half the bearing circumference by a small amount. The small amount is termed .

clearance

crush

pitch

thrust

295

Diesel engine piston ring blow-by is usually caused by excessive ring clearance at the ring .

back

side

gap

bottom

296

Diesel engine piston ring ends can be machined in different shapes. The step-cut ring end offers the advantage of .

having the least amount of ring expansion

best control of ring tension

a decreased break-in period

a decreased possibility of ring seizure

297

Diesel engine piston ring gaps can be straight or angle cut. In comparison, the angle cut ring .

allows piston ring expansion

controls piston ring tension

increases ring wearing quality

decreases combustion gas leakage

298

Diesel engine piston seizure can be caused by .

poor cooling of cylinder walls

improper cooling of the piston

insufficient piston lubrication

all of the above

299

Diesel engine starting difficulties due to cold intake air temperatures, can be overcome by using a/an .

heavier grade of fuel oil

higher viscosity lube oil

compression expansion device

jacket water heater

300

Diesel engine valve springs function to .

hold the valves open

keep the valves off their seats until the exhaust stroke is completed

close the valves

open inlet valves when the air injection cycle begins

301

Diesel engines are classified as reciprocating internal combustion engines because they .

use energy from fuel burned outside their cylinders

burn fuel in a combustion chamber that moves back and forth

burn fuel in a closed chamber which imparts linear motion to pistons

use a continuous combustion process to impart rotary motion to the pistons

302

Diesel fuel oil having a low cetane rating can result in .

improved cold weather starting

smoother engine operation

combustion knock

reduce ignition lag

303

Differential needle valves used in fuel injectors are directly closed by .

cam action

spring force

fuel oil pressure

firing pressure

304

Differential type needle valves in diesel engine fuel oil nozzles, are closed directly by . I. spring pressure II. fuel oil pressure

I only

II only

either I or II

neither I nor II

305

Directional intake ports in diesel engines are used to .

reduce air charge turbulence

induce air swirl

deflect hot combustion gas away from the valves

oppose the effects of piston induced squish

306

Dirt in a fuel oil system of a diesel engine can cause .

damage to strainers

overspeeding of the engine

excessive cooling of the engine

injector damage

307

Dirt lodged on the nozzle valve seat of a fuel injection nozzle will cause .

erosion and cratering of the nozzle orifices

fuel leakage into the nozzle drain line

fuel leakage before and after injection

insufficient fuel delivery through that nozzle

308

Distortion of the spray pattern of a nozzle or injector may be indicated by a/an .

high firing pressure

overload of that particular cylinder

smoky exhaust

cooling water temperature rise

309

Due to excessive water in the fuel, a diesel engine fails to start. Before the engine can be started, the water must be removed from the .

fuel pumps

cylinders

fuel strainers

all of the above

310

During combustion, the sealing surfaces of a diesel engine piston ring are considered to be the ring area in contact with the cylinder wall, in addition to the ring area in contact with the ring groove .

bottom

back

top

side

311

During engine warm-up, the expansion of cylinder head valve stems due to the buildup of engine heat, is compensated for by the .

valve spring tension

hydraulic governor

valve lash clearance

jacket water cooling system

312

During maneuvering operations for a direct reversing large, low-speed, main propulsion diesel engine, which of the following actions is used to stop the shaft from turning prior to changing the engine rotation for a vessel with moderate headway?

Flywheel inertia

Admission of reversing start air

The way of the vessel

Securing cylinder lubricators

313

During normal operation, the liquid retained in space "J" of the device shown in the illustration is .

directly forcing the sliding piston upward to keep the bowl closed

maintaining the bowl oil- water seal interface

lubricating the shaft bearings

maintaining oil pump pressure

314

During operation which device listed removes air and non- condensable gases from the unit shown in the illustration?

"22"

"27"

"25"

"21"

315

During the compression stroke in a four cycle engine, assume that the piston can only travel seven-eighths of the total distance between BDC to the underside of the cylinder head. Which of the following ratios will be the compression ratio for this engine?

6 to 1

7 to 1

7.5 to 1

8 to 1

316

During the compression stroke in a four-stroke/cycle, internal combustion engine, assume that the piston can only travel seven-eighths of the total distance between BDC to the underside of the cylinder head. Which of the following ratios will be the compression ratio for this engine?

6 to 1

7 to 1

7.5 to 1

8 to 1

317

During the diesel engine power stroke, the side thrust developed on the piston is a result of the angle .

formed by the connecting rod and cylinder center line

of the bevel on the piston oil control rings

formed by the crank arm and crank pin

formed by the crank pin and flywheel

318

During the fuel injection period, fuel pressure must exceed cylinder gas pressure to .

ensure penetration and distribution of the fuel in the combustion chamber

ensure the needle valve is flushed clean during each injection

allow combustion gas blowback into the open needle valve

prevent reflected pressure waves when the needle valve closes

319

During the normal operation of the centrifuge shown in the illustration, the operating liquid solenoid and bypass valves for the cleaning cycle should be in which position?

The solenoid valve is closed and the bypass valve is open.

The solenoid valve is closed and the bypass valve is closed.

The solenoid valve is open and the bypass valve is closed.

The solenoid valve is open and the bypass valve is open.

320

During the normal operation of the fuel oil centrifuge shown in the illustration, the flow from the port labeled "B" should be .

clean oil discharging to the day tank

a consistent, heavy flow of separated water to the bilges

an intermittent flow of water to the sludge tank

thick sludge separated from the clean oil

321

During the operation of the fuel oil centrifuge shown in the illustration, it is found that the 'clean' oil discharge contains water. The most probable cause is the .

gravity disk is too large

throughput is too high

separating temperature is currently 95C (203F)

clean oil outlet valve has not been fully opened

322

During the operation of the fuel oil centrifuge shown in the illustration, liquid is passing continuously through the sludge outlet, or the bowl is unintentionally 'shooting'. The probable cause is the .

gravity disk inside diameter is too large

gravity disk seal ring is defective

operating slide seal ring is defective

sliding bowl bottom seal ring is defective

323

During the power stroke of a four-stroke/cycle diesel engine, most of the side thrust of a trunk-type piston is absorbed by the .

piston skirt

pinion

crosshead

compression rings

324

During the power stroke, the side thrust of a trunk type piston is a result of the angle .

formed by the connecting rod and the cylinder center line

formed by the piston in relation to the piston pin

between the crankarm and crankpin

between the master and link connecting rods

325

During the starting of a diesel engine, compression gases are prevented from backing into the air starting system, shown in the illustration, by the .

air starting control valve

individual distribution valves

cylinder air starting check valves

high pressure in the starting air manifold

326

During which of the listed piston strokes of a four- stroke/cycle diesel engine, is the piston moving downward?

Intake stroke

Compression stroke

Exhaust stroke

Pumping stroke

327

Each diesel engine cylinder shown in the illustration is equipped with a/an .

unit injector

individual jerk pump and injector

fuel valve supplied from the common rail

fuel valve, spray valve, and flame plate

328

Early fuel injection in a diesel engine cylinder will generally result in .

an increase in firing pressure

a decrease in firing pressure

an increase in exhaust gas temperature

an increase in cylinder mean effective pressure

329

Early fuel injection timing is indicated by the cylinder pressure being .

above normal with a below normal exhaust temperature

above normal with a normal exhaust temperature

below normal with a normal exhaust temperature

below normal with an above normal exhaust temperature

330

Early injection timing is indicated by .

high exhaust temperature and low firing pressure

high exhaust temperature and high firing pressure

low exhaust temperature and low firing pressure

low exhaust temperature and high firing pressure

331

Electric starting motors for diesel engines require high current for operation and .

require a generator as a source of power

will carry a 100% overload for a brief period

require a current/voltage regulator for proper operation

will overheat if operated continuously over 10 seconds

332

Electric starting motors for diesel engines require high current for their operation. As a result of this, they .

have a generator as a source of power

need a current-voltage regulator for proper operation

are designed as shunt type DC motors

will carry a 100% overload for a brief period

333

Electric starting motors for small auxiliary diesel engines require high current for operation and .

require a generator as a source of power

step-down voltage transformers

require a current/voltage regulator for proper operation

will carry a 100% overload for a brief period

334

Electrically operated safety devices on auxiliary diesel engines function to stop the engine by .

increasing the volume of intake air

shutting off the fuel supply

increasing the engine back pressure

overspeeding the engine

335

Engine coolant accumulating in the diesel engine lubricating oil can result from a .

low oil pressure

high coolant pressure

leaking fuel injector

cracked cylinder head or liner

336

Engine displacement is equal to piston .

area times the piston stroke

area times the piston stroke times the number of cylinders

volume times the piston stoke

volume times the piston stroke times the number of cylinders

337

Engine displacement is equal to the cylinder .

area times the stroke

area times the stroke, times the number of cylinders

volume times the stroke

volume times the stroke, times the number of cylinders

338

Engine protection by means of an alarm or shutdown control can be obtained with devices that are sensitive to .

temperature

pressure

engine speed

all of the above

339

Ethylene glycol, when used as a coolant in a closed cooling system for a diesel engine, is more advantageous than untreated raw water because it .

provides a constant pH below 7

provides better vapor- phase cooling

has a higher freezing point and a lower boiling point

has a lower freezing point and higher boiling point

340

Excess brine accumulated in the distiller, shown in the illustration, is removed during normal operation by .

the hydrokineter labeled "21"

opening the drain valve located to the left of orifice "19"

the continuous action of ejector "22"

orifice "19" regulating the amount of feed water entering the distiller, thereby preventing excess brine accumulation

341

Excessive lube oil consumption can result from worn or broken .

piston rings

valve guides

valve seals

all of the above

342

Excessive lube oil consumption in a diesel engine can be caused by .

late combustion

plugged oil wiper rings

low lube oil temperature

low lube oil pressure

343

Excessive lubricating oil consumption in a running diesel engine can be caused by .

clogged lube oil piping

excessive valve-guide clearance

high lube oil viscosity

low lube oil temperature

344

Excessive piston ring wear in a diesel engine will cause .

high lube oil viscosity

abnormal lube oil consumption

low lube oil temperatures

high firing pressures

345

Excessive piston ring wear in a diesel engine will cause .

high lube oil viscosity

increased lube oil consumption

low lube oil temperatures

high firing pressures

346

Excessive side clearance between a piston ring and its groove will cause the ring to .

expand excessively under operating temperatures

scuff the cylinder liner excessively

hammer the piston land above the ring

hammer the piston land below the ring

347

Excluding line losses, how many distinct pressure drops will occur as sea water flows through all the heat exchangers in the cooling system shown in the illustration?

3

4

5

6

348

Exhaust valve grooving and corrosion is caused by certain components of residual fuel oil. These components are sodium, sulfur, and .

vanadium

carbon

copper

ash

349

Failure to ensure proper venting of the cooling system of a diesel engine can result in .

excessive air charge density

priming in the expansion tank

failure of raw water pump shaft seals

local overheating and/or internal corrosion

350

Failure to establish sufficient vacuum when starting up the unit shown in the illustration may be the result of .

improper operation of the brine pump

improper operation of the distillate pump

neglecting to close the vent shell

neglecting to latch the dump valve

351

Failure to open the diesel engine test cocks after a long period of shutdown, prior to starting may result in .

an air bound fuel system

damage to cylinder heads and pistons

excessive fuel injection

excessive air valve lift

352

Failure to remove the carbon ridge at the top of the cylinder when removing a piston may result in .

damaged upper piston rings and/or ring lands

scored piston walls

damaged cylinder liners

deformed piston skirts

353

Failure to remove the carbon ridge from the top of the cylinder when replacing the piston rings, will result in .

damaged upper piston rings and/or ring lands

scored piston walls

damaged cylinder liners

deformed piston skirts

354

Faulty operation of diesel engine fuel injection nozzles can be a direct cause of .

excessive fuel nozzle holder cooling

sediment in the fuel supply

distortion of the fuel spray pattern

improper atomization of the fuel

355

Faulty operation of diesel engine fuel injection nozzles can be directly caused by .

water in the fuel oil supply

excessive fuel nozzle holder cooling

a distorted fuel spray pattern

leakage past the plunger into the oil drain

356

Figure "D" shown in the illustration is a/an .

scavenging port

air start valve

multi-stage fuel injector

precombustion chamber

357

Fluid type starting motors used for starting auxiliary diesel engines may either be of the piston type or the .

helical screw type

vane type

impeller type

accumulator type

358

Following an overhaul of a crosshead type diesel engine, the engine is jacked over with the turning gear as part of the pre start procedure. Which of the listed pre-start procedures should be carried out?

Ensure proper cylinder lube oil flow.

Open all air space drain cocks.

Open all indicator valves.

All of the above.

359

For a continuous operation diesel engine, a duplex filter unit would be the best arrangement because .

changing filter elements would not interrupt engine operation

filtering occurs twice in each pass of oil through the system

clogging will not occur

dropping pressure is half of that through a single filter unit

360

For a diesel engine, approximately how long can an electric starter motor be operated continuously before damage may begin to occur due to overheating?

Not more than 30 seconds

Not more than 60 seconds

Not more than 90 seconds

Overheating the motor cannot occur.

361

For a given fuel, a change in the compression ratio will affect the ignition lag by which of the listed means?

An increase in compression ratio will increase the ignition lag.

An increase in compression ratio will decrease the ignition lag.

A decrease in compression ratio will decrease the ignition lag.

A decrease in ignition lag will increase the compression ratio.

362

For a given size engine, the two-stroke/cycle diesel engine will deliver more power than a four-stroke/cycle diesel engine because .

it has a longer power stroke

more air gets into the cylinder each stroke

it develops twice as many power strokes at the same speed

higher combustion pressure is developed

363

For any piston ring to operate smoothly without scuffing, the ring must be .

of a material harder than the cylinder liner

properly lubricated

prevented from compressing

prevented from rotating during engine operation

364

For diesel engine piston cooling, lubricating oil can be supplied to the pistons by a/an .

oil spray

oil wick

oil control rings

drilled passage through the camshaft

365

For equal amounts of fuel injected, what change in condition will have the greatest effect on the mean effective pressure in the cylinder of a diesel engine?

TBN of the lubricating oil

Temperature of the lube oil

Completeness in the mixing of the fuel

Temperature of the cooling (sea) water

366

For most auxiliary diesel generator engines, the overspeed trip device will stop the engine by .

moving the governor control to minimum fuel stop

shutting off the lubricating oil supply

tripping the governor emergency stop lever

shutting off the fuel and/or air supply

367

For optimum results, centrifugal purification of heavy fuel oil should be accomplished with the fuel at the lowest practicable .

throughput

additive percent

cetane number

TBN number

368

For the operation of the illustrated device, what fluid flow would be expected at the connection labeled "I"?

The salt water feed.

The distillate discharge.

The sea water used for condensing the water vapor.

Main engine jacket water.

369

Fork and blade type diesel engine connecting rods are shown in the illustration. Which letter combinations represent these components?

"R" and "10"

"M" and "13"

"P" and "10"

"T" and "10"

370

Friction, engine wear, and oil consumption in a diesel engine can be directly attributed to the .

TBN of the oil

pour point of the oil

flash point of the oil

viscosity of the oil

371

From the chart shown in the illustration, if a right hand rotation engine had the #9 piston on top dead center, the #8 piston would be on the .

exhaust stroke

compression stroke

intake stroke

power stroke

372

From the data given in the illustration, which pair of pistons listed are mounted on the same crank throw?

1L/8R

3R/1L

5R/7L

3L/3R

373

From the engine data given in the illustration, what is the swept volume of any one engine cylinder?

182 cubic inches

2800 cubic inches

4766 cubic inches

5712 cubic inches

374

From the engine data given, after cylinder #1L fires, how many degrees of crankshaft rotation must take place before #4L cylinder fires?

22.5

45

67.5

90

375

From the engine data shown in the illustration, what would be the average piston speed if the engine were turning 400 RPM?

1300 ft/min

1400 ft/min

1450 ft/min

1500 ft/min

376

From the graph shown in the illustration, determine the size of the regulating ring required for the proper operation of the fuel oil centrifuge if the fuel oil specific gravity is 0.9 kg/dm3 at 68F, and the separating temperature is 158F.

86 mm

104 mm

110 mm

117 mm

377

From the graph shown in the illustration, if the separating temperature required is to be 167F, and the specific gravity of the oil is .98 kg/dm3 at 59F, what size regulating ring is required?

86 mm

89 mm

92 mm

95 mm

378

Fuel combustion in a diesel engine cylinder should begin just before the piston reaches top dead center and should .

end when fuel injection has been completed

end at bottom dead center

continue through the after-burning period

be completed exactly at top dead center

379

Fuel delivery to the cylinder is terminated when the .

helix on component "H" uncovers the spill port

cam follower is located on the base circle

spill valve opens

delivery check valve opens

380

Fuel delivery to the cylinder is terminated when the .

helix on component "H" uncovers the spill port

cam follower is located on the base circle

spill valve controlled by "I" opens

delivery check valve opens

381

Fuel droplets injected into a diesel engine cylinder must have adequate penetration to .

prolong the ignition delay period

ensure the beginning of fuel injection

thoroughly utilize the air charge

allow controlled fuel combustion

382

Fuel injection pumps using the port and helix metering principle requires the use of a .

crosshatched design

lapped plunger and barrel

variable stroke

variable cam lift

383

Fuel injection systems are designed to primarily meter fuel, atomize fuel, and .

create turbulence in the combustion chamber

aid in completing cylinder scavenging

inject fuel at the proper time

minimize fuel penetration into the cylinder

384

Fuel injector nozzles are usually of the multi-orifice type with the number and placement of the holes arranged according to the .

type of piston rings

pressure of the fuel system

size of the pump plunger spring

design of the combustion chamber

385

Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce .

cold corrosion of the nozzles

fuel viscosity for better atomization

carbon accumulation on the nozzles

fuel detonation in the cylinders

386

Fuel is admitted to a diesel engine cylinder through the .

intake valves

carburetor

exhaust ports

injector nozzles

387

Fuel is ignited in a diesel engine cylinder by .

a spark plug

injectors

the heat of compression

increasing jacket water temperatures

388

Fuel oil contamination of an auxiliary diesel engine lube oil can result in .

an increased flash point

higher lube oil pressures

an increased viscosity

lower lube oil pressures

389

Fuel oil day tanks for diesel engines must be checked and cleaned at regular intervals in order to remove .

sludge

water

micro-organism growth

all of the above

390

Fuel oil discharged into the diesel engine cylinder is atomized at the .

turbocharger

injector nozzle tip

carburetor

fuel oil pump

391

Fuel oil having a low cetane rating could result in .

improved cold weather starting

excessive fuel oil consumption

reduced ignition lag

smoother engine operation

392

Fuel oil injected into the cylinder of a diesel engine just after the piston passes top dead center, will .

increase engine power

increase engine load

decrease engine power

improve fuel economy

393

Fuel oil is regularly transferred to the day tank in order to .

allow impurities to settle out of the fuel

allow for decanting of water

make fuel available for immediate use

all of the above

394

Fuel oil penetration into the cylinder of a diesel engine is .

dependent on fuel injection cut-off

reduced by finer atomization

increased by finer atomization

nonexistent in the precombustion chamber system

395

Fuel oil penetration into the cylinder of a diesel engine is .

dependent on air turbulence

reduced by finer atomization

increased by finer atomization

nonexistent in the precombustion chamber system

396

Fuel oil strainers should be made of . I. copper II. Brass

I only

II only

either I or II

neither I nor II

397

Fuel supplied by each unit injector on a two-stroke/cycle single acting diesel engine is directed into each cylinder at a very high pressure through the .

high pressure fuel line

spill deflector

check valve

spray tip of the injector

398

Fuels as produced in a refinery are generally sterile, however, contamination can occur as fuels are .

stored at the refinery

stored on the vessel

transported to the distribution sites

All of the above are correct.

399

Generally, where should you expect to find the greatest amount of wear on a cylinder liner?

Adjacent to the piston skirt when the crank is on TDC.

Along the lower part of the liner wall opposite the oil control ring.

Opposite the top ring shortly after piston travel has ended the compression stroke.

Opposite the oil control ring when the crank is on bottom dead center.

400

Heat damage to fuel injection nozzles can be prevented by avoiding .

excessive fuel oil temperature

long periods of engine overload

metallic contact between nozzles and cylinder heads

hard carbon deposit and varnish on the nozzles

401

Heat damage to fuel injection nozzles on small high-speed diesel engines, can be prevented by .

employing fuel oil as a cooling medium

preventing hard carbon deposit on nozzle tips

avoiding fuel oil temperature exceeding builder's specification

ensuring good metallic contact between nozzles and cylinder heads

402

Heat exchangers are most commonly found in a small auxiliary diesel engine .

fuel oil system

governing system

air starting system

lube oil system

403

Heat for igniting the fuel oil in the cylinder of a diesel engine is generated by the .

electronic ignition system

compression of air by the piston

friction in the fuel injector

fuel oil heating system

404

Heavy fuel oil used in the system shown in the illustration, will have the lowest viscosity .

at the transfer pump discharge

in the settling tank

in the three-way valve

at the main engine fuel oil header

405

Heavy residual fuel oils are heated prior to centrifuging to .

reduce fuel weight

increase specific gravity

separate fuel from lube oil

reduce fuel viscosity

406

High cylinder firing pressure, accompanied by low exhaust temperature, can result from .

improper fuel rack positioning

lengthy exhaust valve duration

extended operation at light load

excessively early injection timing

407

High diesel engine cooling water temperatures can be caused by .

air in the cooling system

an open thermostat

maintaining only 1/2 an expansion tank level

excessive cooling water pump pressures

408

High diesel engine cooling water temperatures can be caused by .

a worn water pump

not enough coolant

air in the cooling system

all of the above

409

High lube oil temperature developing in a diesel engine generally results from .

high oil pressure

excessive bearing end play

plugged oil control rings

engine overload

410

High velocity turbulence is imparted to the air charge to the diesel engine, shown in the illustration, by .

masked intake valves

directional intake ports

a Mexican hat piston crown

a precombustion chamber

411

Higher than normal jacket water temperatures occurring in all cylinders of a diesel engine can result from a/an .

oil suction line restriction

correct amount of coolant

cavitation erosion in the water jackets

clogged sea suction strainer

412

High-speed, multi-cylinder, diesel engines commonly use counterweights placed opposite to the crankpins to .

prevent bearing loads

provide dynamic balance by equalizing centrifugal force

counteract inertia forces

provide a balance of rocking couples around the crankshaft

413

How can water enter the crankcase of an operating diesel engine?

Through the crankcase exhauster.

As water vapor contained in blow-by.

Demulsifying lube oil passing through the main bearings.

Condensation from vapor formed in the expansion tank.

414

How is lubrication provided to the device shown in the illustration?

A separate system containing oil under extremely high pressure is used due to its ability to provide a high film strength.

Only silicate ester based synthetic oils have the capability and necessary characteristics to be used in this type of application.

The lubrication system closely resembles the system used with standard line shaft bearings.

The lube oil enters through the supply pipes shown as #11 and eventually drains to the main engine sump.

415

How is oil supplied to the device shown in the illustration?

An attached positive displacement pump supplies oil to the separator.

The oil inlet paring disc creates a low pressure in the suction piping.

In this arrangement an independent pump is utilized.

This purifier as well as most others will be installed in the lower engine room to make use of gravitational forces.

416

How is the illustrated strainer element cleaned during engine operation?

The drain plug is removed and the housing is drained.

The housing is removed and the element is cleaned with a solvent.

The T-handle is rotated.

The strainer element is removed, cleaned in kerosene or solvent, and dried with an air brush.

417

How is the pressure and temperature affected in a diesel engine cylinder during compression?

Pressure and temperature decrease

Pressure and temperature increase

Pressure decreases and temperature increases

Pressure increases and temperature decreases

418

How many crank angle degrees of rotation exist between each firing of the cylinders indicated by the illustrated chart?

60

120

180

240

419

How many power strokes per crankshaft revolution are there in an eight cylinder, two-stroke/cycle diesel engine?

One

Two

Four

Eight

420

How many separate camshaft timing events must be controlled for the components of an air start cylinder head for a direct reversible, four stroke diesel engine?

4

6

7

8

421

How many separate initial timing events must be controlled in the cylinder head of a direct admission air start, direct reversible, four stroke diesel engine?

2

4

6

8

422

How may water be removed from the bowl of the separator as shown in the illustration?

The water may be removed through the water drain valve or through the sludge ports during the sludge discharge cycle.

The separator is used to remove solids from the processed liquid, therefore the accumulation of water does not present a problem.

When the unit is secured and the bowl stops rotating, the water is drained off the bottom of the bowl through orifice ports.

Water may only be removed from the bowl when the unit is secured and the bowl hood is removed.

423

How often should the lubricating oil of a diesel engine be changed?

After every trip

Every 4000 hours

According to manufacturer's instructions

Every time they are shutdown

424

Hydraulic starters are installed on many lifeboat diesel engines instead of comparable air start systems, because .

hydraulic starters are the least expensive of all starting systems

the system does not require high pressure piping

hydraulic systems turn diesel engines at higher rates of speed than air starters

the system can be manually recharged

425

If a crankcase explosion has occurred in a diesel engine, and the crankcase remains intact, which of the following precautions should be observed?

The cylinder indicator cocks should be opened.

The sump lube oil scavenge pump should be secured immediately.

The explosion relief valves should be manually opened.

The crankcase should remain unopened until the engine has cooled.

426

If a crankcase explosion occurs in a diesel engine, which of the listed actions should be taken?

Open the crankcase immediately to cool the engine sump.

Apply fire fighting water through the crankcase breather.

Secure the engine and allow the engine to completely cool before opening the crankcase.

Allow the engine to idle for 5 minutes before shutting down.

427

If a crankcase explosion occurs in a diesel engine, you should stop the engine and .

immediately open all crankcase relief ports

increase crankcase exhauster speed to draw cool air into the engine

allow the engine to cool down naturally before opening the inspection covers

increase crankcase scavenge air to remove unburned gases

428

If a diesel engine can be turned over at normal cranking speed but fails to start, the cause could be late fuel injection or .

excessive fuel pressure

high lube oil viscosity

fuel oil trip has not been reset

excessive starting air pressure

429

If a diesel engine driving a generator turns over freely but fails to fire properly, the cause could be .

excessive compression pressure

air in the fuel lines

high fuel pressure

excessive load

430

If a diesel engine fails to start, one of the likely causes is .

low compression temperature

low ambient air pressure

high lube oil pump pressure

high fuel oil booster pump pressure

431

If a diesel engine has been stopped because of piston seizure due to severe overheating, the crankcase .

inspection covers should not be opened until the engine has cooled

ventilation system should be continued in operation for one hour for cooling

scavenge pump should be immediately secured to prevent loss of lube oil

explosion covers should be opened slightly to provide extra ventilation

432

If a diesel engine hydraulic starting motor fails to disengage from the engine, your FIRST check should be the .

throw-out bearing

hydraulic pump

overrunning clutch

accumulator

433

If a diesel engine is difficult to start when operating in low ambient temperature conditions, you should suspect that the .

compression pressures are below normal

lube oil is diluted with fuel oil

cranking speed is too low

exhaust system is partially restricted

434

If a diesel engine rotates slowly when cranked, but does not fire, the .

fuel control rack had admitted excessive fuel

engine speed does not match the fuel rack setting

engine has failed to reach its firing speed

starter pinion and ring gear contact is not correct

435

If a diesel engine runs out of fuel, you can expect trouble from .

overheated injector pumps

water condensed in the cylinders

fuel dilution of the lube oil

air in the fuel system

436

If a diesel engine runs roughly, which of the systems listed is most likely to be at fault?

Fuel

Lubricating

Cooling

Ignition

437

If a diesel engine turned over at normal cranking speed but failed to start, the cause could be late fuel injection or .

excessive fuel pressure

high lube oil viscosity

air in the fuel injectors

excessive starting air pressure

438

If a diesel engine turned over freely but failed to start, the cause could be .

water in the fuel

cold lube oil

excessive starting air pressure

excessive fuel pressure

439

If a diesel engine were running at 20% overload with a smoky exhaust, you should .

stop the engine immediately to prevent damage

increase lube oil pressure

slow the engine allowing it to gradually cool

decrease the cooling water temperature to the water jacket

440

If a diesel engine, with an electric starter, cranks very slowly after repeated attempts to start, the cause could be .

low lube oil viscosity

low compression pressure

a faulty Bendix-drive

an overheated starting motor

441

If a few injector spray holes become plugged, the result could be .

excessive surging at governed speed

combustion knock under load

poor fuel combustion

all of the above

442

If a four-stroke/cycle diesel engine is running at 1550 RPM, the speed of the camshaft will be .

525 RPM

775 RPM

1550 RPM

1800 RPM

443

If a four-stroke/cycle diesel engine is started by admitting high pressure air into the cylinders, the pistons receiving the charge of starting air must be .

on the power stroke

on the exhaust stroke

at the end of the power stroke

at the start of the intake stroke

444

If a hydraulic starting motor turns, but the diesel engine does not, the most likely cause is .

excessive viscosity in the hydraulic fluid

a malfunctioning overrunning clutch

loss of accumulator precharge

air in the hydraulic system

445

If a particular liquid has a specific gravity of .96kg/dm3 at 77F, what will be the specific gravity of the liquid, as determined from the graph shown in the illustration, if the temperature is increased to 167F?

.910 kg/dm3

.915 kg/dm3

.920 kg/dm3

.925 kg/dm3

446

If a sample of engine lube oil indicates excessive fuel dilution, the lube oil should be .

changed

centrifuged

filtered

settled

447

If a single cylinder relief valve on a diesel engine lifts frequently while the engine is running, the cause may be an .

excessively late injection timing for each cylinder

incorrectly adjusted intake valve timing

incorrectly adjusted fuel injector

incorrectly adjusted intake valve clearance

448

If a single cylinder relief valve on a main propulsion diesel engine begins to lift, but it is not possible to secure the engine, which of the following actions should be taken?

Increase the cooling water flow to the engine.

Secure or reduce fuel to that cylinder.

Screw down on the pressure adjusting spring to decrease popping pressure.

Readjust the injection timing.

449

If a small auxiliary diesel engine will not crank but can be barred over, the trouble may be due to .

corrosion of starting battery terminal connections

air bound fuel injectors

a leaky fuel pump relief valve

a defective engine governor

450

If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two-stroke/cycle diesel engine will develop approximately .

the same indicated horsepower as a four- stroke/cycle engine

twice the indicated horsepower as a four- stroke/cycle engine

one half the indicated horsepower as a four- stroke/cycle engine

one power stroke for every two crankshaft revolutions

451

If an analysis of a sample of used engine lube oil shows a high concentration of ethylene glycol, this probably indicates that .

the air filtration is inadequate

engine coolant is leaking into the lube oil

fuel oil is leaking into the lube oil

the piston rings are excessively worn

452

If an analysis of a sample of used engine lube oil shows a high concentration of sodium nitrite, this probably indicates that .

the air filtration is inadequate

engine coolant is leaking into the lube oil

fuel oil is leaking into the lube oil

the piston rings are excessively worn

453

If an auxiliary diesel engine coolant temperature is higher than normal, but the thermostat is determined not to be defective, you would suspect a/an .

cavitation erosion in the water jackets

excess corrosion inhibitor in the coolant

dirty jacket water cooler

defective turbocharger

454

If an auxiliary diesel engine equipped with an electric starting system cranks very slowly after repeated attempts to start, the cause could be a/an .

low lube oil viscosity

low compression pressure

ring gear with broken teeth

overheated motor windings

455

If an auxiliary diesel engine frequently stalls, the trouble may be caused by .

low exhaust back pressure

air in the fuel system

gasket blow-by or leakage

incorrect assembly of idler springs

456

If an auxiliary diesel engine will not crank but can be barred over, the trouble may be .

starting batteries

water in the cylinder

the driven component is seized

sea suction valve is closed

457

If an auxiliary diesel engine will not crank but can be barred over, the trouble may be in the .

starting batteries

fuel injectors

fuel pump

engine governor

458

If an auxiliary diesel engine will not crank but can be barred over, the trouble may be due to .

corrosion on the battery connections

stuck fuel injectors

air bound fuel pump

low oil level in the engine governor

459

If an auxiliary diesel engine will not crank but can be barred over, the trouble may be in the .

corroded battery connections

fuel injectors

fuel pump

engine governor

460

If an small auxiliary diesel engine will not crank but is able to be barred over, the trouble may be .

corrosion on the starting battery connections

water accumulation in a cylinder

the driven component is seized

sea suction valve is closed

461

If clearance between a piston and the cylinder wall is excessive, piston slap will occur. The slap itself is caused by .

alternation of side thrust

a breakdown of the lube oil film on the cylinder wall

worn piston boss piston pin bearings

fluctuating gas pressure in the combustion space

462

If cranking a diesel engine is too slow while attempting to start, it will result in .

insufficient heat of compression

fouling of the air intakes

improper injection timing

high exhaust temperatures

463

If diesel fuel was discharging from the waste water outlet of a disk type centrifugal purifier operating as a separator you should .

reprime the purifier

remove the discharge ring

slow the purifier to its proper speed

put in an additional discharge ring

464

If fuel injection in a diesel engine begins earlier than the design start of injection, ignition may be delayed because the .

fuel oil injection pressure may not be high enough

cylinder compression pressure may not be high enough

cylinder compression temperature may be too high

scavenge and purge process is incomplete

465

If fuel injection occurs too early, a diesel engine will lose power because the .

fuel will not be properly atomized in the cylinder

ignition will be delayed due to low compression pressure

maximum fuel expansion will occur on the compression stroke

fuel will ignite after top dead center

466

If fuel injection to a four-stroke/cycle diesel engine begins earlier than designed, ignition may be delayed because the .

cylinder compression pressure may not be high enough

cylinder compression temperature may be too high

fuel oil injection pressure may not be high enough

scavenge and purge process is incomplete

467

If fuel oil were being discharged from the waste water outlet of a fuel oil disk type centrifuge, operated as a separator, you should .

remove the discharge ring

reprime the purifier with sealing water

slow the centrifuge to its proper speed

install an additional discharge ring

468

If it becomes necessary to clean the spray holes in a diesel engine fuel injector, you should use a suitable size piano wire and .

gasoline

carbon solvent

degreasing compound

strong detergent

469

If it becomes necessary to cutout an individual cylinder of a large, low-speed, main propulsion diesel engine, the fuel to that cylinder should be secured and its .

fuel pump should be removed and all connections blanked off

cylinder oil feed rate should be increased slightly above that used at normal sea speed

cylinder oil feed rate should be reduced

cylinder oil feed rate should be increased to the maximum flow capable of the metering pump

470

If item "F" begins leaking during operation, which of the following operating conditions will NOT occur?

The oil/water interface will move outward from the vertical axis of the machine.

The water seal will be lost.

The oil/water interface will remain in the same neutral position.

The unit will not properly operate and should automatically shut down.

471

If lost motion is present in an individual fuel injection pump, which of the following problems will occur?

Fuel injection will be increased.

Fuel injection will remain unchanged.

Fuel injection will occur earlier.

Fuel injection will occur later.

472

If point #1 in the diagram shown is the beginning of gas compression, which of the cycles listed is being illustrated?

Otto

Diesel

Gas Turbine

Rankine

473

If sludge accumulates on the underside of a diesel engine piston, it will .

cause blow-by

chemically attack the piston skirt

form an emulsion of lube oil and water

raise the piston temperature

474

If the air supply to the 'liquid sensor' of the device shown in the illustration is secured accidently, which of the following alarms will be indicated?

AO6: liquid indication.

AO7: transducer fault.

Low pressure in oil inlet.

Low pressure in oil outlet.

475

If the analysis of used lube oil indicates a high content of iron particles, this could indicate .

corrosive deterioration of a bearing

inadequate air filtration

excessive ring and liner wear

excessive cooling of lubricating oil

476

If the back clearance of a piston ring is excessive, .

compression pressure in the cylinder will be higher

carbon will accumulate behind the ring

combustion gases will penetrate beneath the ring land

piston side thrust will be increased

477

If the bowl of a disk type centrifugal purifier when operated as a separator is not primed, the .

oil has a tendency to emulsify in the bowl

purifier will act as a clarifier at the discharge ring

oil will be lost through the water discharge ports

oil solids will be deposited only at the intermediate top disk

478

If the compression ratio is increased on any diesel engine, .

the expansion ratio will decrease

combustion will be slowed down

thermal efficiency will decrease

thermal efficiency will increase

479

If the compression rings on a diesel engine piston become stuck in the ring groove, the cause may be due to .

excessive ring action

excessive ring temperature

improper ring rotation

excessive ring face wear

480

If the control unit as shown in the illustration indicates alarm A01 'abnormal water content', the operator should suspect .

that the operating water tank is about to overflow

that the bowl is fouled and cleaning is necessary

an extremely high percentage of water in the fuel

faulty seals between the sliding bowl bottom and the paring disc assembly

481

If the coolant temperature is excessively low as it passes through the internally cooled fuel injectors, the injectors may be damaged by .

water condensation in the fuel

corrosion of the nozzle tip

carbon deposits on the leak off inlet

over lubrication of the needle valve

482

If the coolant temperature is too low as it passes through internally cooled fuel injectors, the injectors can be damaged by .

water condensation in the fuel

corrosion of the nozzle tip

decrease in fuel oil viscosity

inadequate lubrication of the needle valve

483

If the coolant temperature is too low as it passes through internally cooled fuel injectors, the injectors can be damaged by .

water condensation in the fuel

corrosion of the nozzle tip

low cylinder head temperatures

inadequate lubrication of the needle valve

484

If the coolant temperature of a closed cooling water system for a diesel engine gradually increases, the trouble usually is .

a broken shaft on the freshwater pump

excessive fouling of the heat exchanger

an incorrect thermostatic element operating range

lube oil in the cooling water

485

If the cooling water temperature and the lube oil temperature in a diesel engine are too high, the cause can be .

a dirty lube oil strainer

internal water leaks

an oil suction line restriction

excessive wear of the cooling water pump

486

If the demister used in the device shown in the illustration is improperly installed, which of the following will occur?

The vacuum of the device will increase.

The temperature of the device will decrease.

Interstage leakage will cause a decrease in output.

There will be an increase of chlorides measured at the distillate pump salinity cell.

487

If the detergent type lubricating oil being used in a diesel engine is black, the oil .

must be centrifuged

must be filtered

must be changed

is holding finely dispersed carbon in suspension

488

If the diesel engine fuel injection timing is changed to delay the start of injection until the pistons are at top dead center, the engine will .

backfire through the air intake

develop less power under load

have high firing pressures

lift its cylinder relief valves

489

If the diesel engine starter-drive mechanism fails to disengage after the engine starts, which of the following situations will occur?

The engine will stall.

The starter motor will have reverse current.

The engine flywheel will be burred.

The starter motor will overspeed.

490

If the discharge valve "F" of the fuel injection pump, shown in the illustration, allows fuel to leak out from the high pressure fuel line, which of the following conditions would occur?

Injection timing will be advanced

Air bubbles will form in the fuel return line

Effective length of stroke will be increased

Effective length of stroke will be decreased

491

If the discharge valve of the fuel injection pump, shown in the illustration, leaks during operation, which of the following conditions should be expected?

Injection timing will be increased.

Fuel will leak into the return line.

Effective length of stroke will be increased.

Effective length of stroke will be decreased.

492

If the firing pressures in a diesel engine are high, although the exhaust temperatures are normal, the cause may be .

late injection timing

worn orifices in the injection nozzles

carbon buildup on the piston

using a fuel with too high of a cetane number

493

If the interval of time associated with the ignition delay period occurring in the cylinder of a diesel engine is lengthened, what will be the result?

Less fuel will enter the cylinder.

The cylinder compression pressure will be lower.

The fuel combustion will be more complete.

The rise in combustion (firing) pressure will be more rapid.

494

If the jacket water temperature in an auxiliary diesel engine cooling system is lower than normal, the probable cause is .

air binding of the engine cooling system

a cracked water cooled exhaust manifold

blockage in the heat exchanger

faulty operation of the thermostat

495

If the jacket water temperature of an operating diesel engine suddenly rises above normal, the cause can be attributed to .

an overfilled expansion tank

excess chromate treatment of the jacket water

a clogged raw water sea suction

cavitation erosion of the heat exchanger tubes

496

If the jacket water temperature rises rapidly above normal in a diesel engine, you should FIRST .

place standby cooler in operation

reduce engine load

check thermostatic valve

clean sea water strainer

497

If the jacket water temperature rises rapidly above normal in a diesel engine, you should FIRST .

call the chief engineer

reduce engine load

check thermostatic valve

clean sea water strainer

498

If the low level alarm of the diesel fuel day tank fails to function, you can expect trouble from .

overheated injection pumps

water condensed in the cylinders

fuel dilution of the lube oil

air in the fuel system

499

If the manufacturer advises of a normal lube oil consumption for a 4000 horsepower (2982.8 kW) diesel engine to be .0001 gal/hp-hr, (.5076 mL/kW-hr), how much oil should the engine consume in one 24 hour period if operated at full load?

6.4 gallons (24.23 L)

9.6 gallons (36.34 L)

11.4 gallons (43.15 L)

14.4 gallons (54.51 L)

500

If the manufacturer's instructions do not state otherwise, which of the following progressions represent the best order for tightening the head bolts shown in the illustration?

1 5 3 7 2 6 4 8

1 2 3 4 5 6 7 8

2 4 6 8 1 3 5 7

7 2 3 6 5 8 4 1

501

If the needle valve in a fuel injection nozzle sticks open, .

fuel will leak into the nozzle drain line

no fuel will be delivered through the nozzle

the nozzle will overheat

injection lag will be increased

502

If the oil control rings were installed upside down on a diesel engine piston, which of the following conditions would result?

Excessive oil pumping would occur.

The rings would tend to overheat.

The ring grooves would be blocked.

Tendency for ring breakage is increased.

503

If the oil scraper ring drain hole in a diesel engine piston becomes plugged, .

blow-by will decrease

oil consumption will decrease

oil consumption will increase

the ring will immediately seize and buckle

504

If the operating element of a thermostatic valve installed in a diesel engine cooling system malfunctions, it may result in .

a low level in the engine expansion tank

excessively high coolant pressure

improper temperatures

malfunctioning of the jacket water heater

505

If the piston groove drain holes for the oil control rings become clogged, which of the following is likely to occur?

The oil control rings will seat improperly and wear rapidly.

The piston will overheat due to insufficient lubrication.

Excessive oil will remain on the cylinder wall.

Light brown smoke will emanate from the engine exhaust.

506

If the piston stroke in a four stroke cycle diesel engine is 10 1/2 inches and the speed of rotation of the crankshaft is 720 RPM, what is the average piston speed?

1200 feet/minute

1260 feet/minute

1320 feet/minute

1380 feet/minute

507

If the plunger or barrel of a fuel injection jerk pump becomes damaged, .

the entire pump must be replaced

the injection pump and injection nozzle must be replaced

either the barrel or plunger must be replaced

the barrel and plunger must be lapped and blued.

508

If the plunger or barrel of a fuel injection jerk pump becomes damaged, .

only the replacement of the entire pump would be acceptable

the injection pump and injection nozzle must be replaced

either the barrel or plunger must be replaced

the barrel and plunger must be replaced as a unit

509

If the raw water supply pressure for a diesel engine cooling system is below normal, you should check for a .

broken thermostat

clogged sea strainer

blown head gasket

cracked head

510

If the regulating valve V4 shown in the illustration vibrated open, which of the following alarm conditions would be indicated at the program unit panel?

Low pressure in oil outlet.

Low oil temperature after preheater.

High oil temperature after preheater.

No discharge.

511

If the relief valve on a diesel engine cylinder lifts, the cause could be due to .

liquid in the cylinder

low compression in the cylinder

high exhaust temperature

poor fuel penetration

512

If the separating temperature is to remain constant, what is the relationship between the specific gravity of the oil and the required size of the regulating ring?

For a constant operating temperature, the greater the specific gravity of the oil the larger the regulating ring.

The specific gravity of the oil and the size of the regulating ring are related only during the initial design stages of the centrifuge.

With oils of greater specific viscosities it is proper to select smaller regulating rings regardless of the operating temperatures desired.

The larger sized regulating rings are designed to be used with oils of lower specific gravities.

513

If the speed of the propeller is 135 RPM, the speed of the engine camshaft shown in the illustration will be .

135 RPM

270 RPM

variable depending on the camshaft gear train gear ratios

variable depending on the ratio between engine rpm and propeller shaft rpm

514

If the water level dropped rapidly in the expansion tank of a closed diesel engine cooling water system, you should suspect a .

loss of suction in the circulating pump

leak in the system heat exchanger

broken raw water pump shaft

burned or cracked piston in one cylinder

515

If the wearing rings of device "7" shown in the illustration become worn, how will the evaporation rate in "23" be affected?

The rate of evaporation will decrease.

The rate of evaporation is dependent on the level of vacuum maintained within the unit, and not the flow of water to the unit.

Device "7" does not use wearing rings, as these are normally positive displacement pumps.

The rate of evaporation will not be affected as the standby pump, labeled "8" will be used instead.

516

If uneven sludge deposits accumulate in the sludge space of the bowl assembly of the device shown in the illustration, .

an alarm for 'emergency stopping or vibrations' may be indicated

the machine will continue to operate indefinitely

the shoot cycle should be automatically be initiated at more frequent intervals

there are excessive quantities of micro- organisms in the fuel supply

517

If valve "D" is opened during the normal operation of the distiller shown in the illustration, which of the events listed will occur?

The amount of vapor formed in the evaporator will increase.

The jacket water cooler will be overloaded, eventually causing a critical engine alarm.

The output of pump "7" will increase with a corresponding increase in pressure.

The amount of vapor being formed in the evaporator will decrease.

518

If valve "H" shown in the illustration is opened wide while the distiller is in operation, .

the absolute pressure of the unit will increase with an associated decrease in shell temperature.

the absolute pressure of the unit will increase due to the increased affect of the air ejector.

the absolute pressure of the unit will increase with an associated increase in shell temperature.

the absolute pressure of the unit will not be affected, but the rate of condensation will be decreased.

519

If water is found in the crankcase of a diesel engine, the cause may be due to .

a cracked cylinder head

a leaky cylinder head gasket

a cracked cylinder liner

all of the above

520

If while attempting to start a diesel engine, the cranking speed is too low, .

the fuel timing will be too late

the heat of compression will be insufficient to ignite the fuel

the lube oil viscosity will be too low

the spark will be too early for the fuel

521

If you determine that entrained air in the fuel oil system is causing a diesel engine to stall, you should first check for .

fuel leakage in the injector pump's discharge lines

worn gaskets in the transfer pump discharge lines

partially clogged fuel oil discharge strainers

loose fittings in the booster fuel pump suction piping

522

If you notice smoke coming from the crankcase exhaust fan outlet of an operating diesel engine, you would suspect .

a cracked cylinder liner

clogged intake ports

broken piston rings

a faulty head gasket

523

If you suspect a diesel engine is misfiring due to air leakage into the fuel system, you should begin looking for the leak at the .

fuel line connections to the cylinder injection valves

gasket surfaces of the fuel oil filters

discharge fittings of the fuel injector pumps

suction side of the fuel oil booster pump

524

Immediately after any diesel engine is started, the engineer should first check the .

crankcase pressure

lube oil pressure

saltwater pressure

exhaust temperature

525

Immediately after starting a diesel engine, normal raw water and jacket water pressures are indicated. However, the jacket water temperature continues to rise. If there is no change in the sea temperature, you should suspect .

overloading in all cylinders

a jammed three-way thermostatic valve

chromate pH too low

a high level in the surge tank

526

Immediately after starting a diesel engine, you should first check and monitor the .

cooling water temperature

lube oil temperature

fuel pressure

lube oil pressure

527

Immediately after starting a small high-speed diesel engine, you should check the .

cooling water temperature

lube oil temperature

fuel pressure

lube oil pressure

528

Immediately at the end of the sludge ejection cycle, the bowl of the fuel oil centrifuge, shown in the illustration, will be closed only when the valve(s) .

V5' is closed, with 'V10,' 'V15,' and 'V16' are open

V5,' 'V10,' 'V15,' and 'V16' are closed

V10' and 'V16' are open, with 'V15' and 'V5' closed

V5,' 'V10,' 'V15,' and 'V16' are open

529

Improper cooling of a diesel engine cylinder liner due to the accumulation of scale deposits, may cause .

low compression pressure

increased piston wear

increased cylinder lube oil consumption

poor contact between compression rings and liner

530

Improper seating of an air starting check valve in an operating diesel engine is indicated by .

noise coming from the air starting valve

an overheated air supply pipe to the cylinder head

continuous operation of the starting air compressor

zero air pressure in the air starting system

531

Improperly fitted piston rings in a diesel engine can result in .

excessive lube oil consumption

lower than normal lube oil temperature

higher than normal exhaust back pressure

excessive crankshaft end play

532

In a Bendix starter drive, the pinion engagement with the flywheel ring gear is initiated by .

Bendix spring pressure

starter drive shaft rotation

a differential spring

solenoid throw out action

533

In a bypass type filtering system for a medium or high speed diesel engine, the lube oil bypassing the filter .

returns directly to the suction side of the pump

returns directly to the sump

flows to the engine bearings

flows through a second- stage strainer, reheater, and returns to the sump

534

In a bypass type filtering system for a medium or high speed diesel engine, the lube oil passing through the filter .

returns directly to the suction side of the pump

returns directly to the sump

flows to the engine bearings

flows through a second- stage strainer, reheater, and returns to the pump suction

535

In a bypass type lubrication system for a diesel engine, the clean oil line from the filter directs the oil to the .

lube oil sump

lube oil pump discharge line

lube oil pump suction line

outlet of the lube oil header

536

In a bypass type lubrication system for a diesel engine, the dirty oil line to the centrifuge should be taken from the .

lube oil pump suction line

lube oil pump discharge line

bottom of the lube oil sump

outlet from the lube oil header

537

In a closed cooling system for a turbocharged, four- stroke/cycle diesel engine, fluctuating water pressure can be caused by .

improper venting of the cooling system

carrying the expansion tank water level too high

a totally clogged impeller in the cooling water pump

an incorrectly set cooling system temperature control

538

In a closed cooling water system, which of the following problems can cause the water pressure to fluctuate?

An open vent in the cooling system.

A fouled sea chest.

A restricted water passage in the engine.

Air entrained in the cooling water.

539

In a diesel engine closed freshwater cooling system employing a radiator, proper water temperature can be obtained by .

adjusting the radiator louvers

passing cooling water through a space heater

passing cooling water through the lube oil cooler

piping exhaust gases across the radiator front

540

In a diesel engine closed freshwater cooling system, the amount of engine coolant flowing through the heat exchanger is controlled by the .

suction pressure regulator

thermostatic bypass valve

sea water temperature

water level in the expansion tank

541

In a diesel engine closed freshwater cooling system, the cooling water pressure drop through the engine is 10 psig, and the pressure drop through the heat exchanger is 4 psig at maximum flow rates. The cooling water pump must produce a discharge head of at least .

4 psig

6 psig

15 psig

28.7 psig

542

In a diesel engine cooling system, the high temperature alarm contact maker will be activated on excessively high water discharge temperature from the .

raw water pump discharge

expansion tank outlet

cooling water heat exchanger outlet

engine jacket water outlet

543

In a diesel engine cooling water system, a pH of 6.0 indicates a/an .

slightly acidic condition

slightly alkaline condition

overtreatment of water

neutral condition of water

544

In a diesel engine fuel oil jerk pump, the amount of fuel that will be forced through the spray nozzle on each upward stroke of the plunger depends upon .

the pump supply pressure

the slope of the fuel cam

how much the plunger had been rotated by the rack

the number of sleeve segments engaged with the rack

545

In a diesel engine jacket water cooler, with seawater cooling the fresh water, the .

sea water temperature must never be warmer than 40F

jacket water pressure should always be greater than the sea water pressure

jacket water temperature must always be less than 60F

jacket water pressure must always be less than the sea water pressure

546

In a diesel engine lube oil system, which of the following components should be lubricated first?

Wristpin bearings

Main bearings

Piston crowns

Crosshead guides

547

In a diesel engine lube oil system, which of the following parts should be lubricated first?

Wristpin bearings

Main bearings

Piston crowns

crankpin bearings

548

In a diesel engine mechanical-type fuel pump, the delivery check valve is opened by .

push rod action

cam action

hydraulic action

spring action

549

In a diesel engine starting motor equipped with a Bendix drive, the pinion moves and meshes with the flywheel ring gear due to .

shifting levers of solid mechanical linkage

the shaft sleeve spiral helix and relative rotation between pinion and starter shaft

centrifugal force developed from rotation

electromotive force developed at the flywheel

550

In a diesel engine, maximum lube oil system pressure under cold start conditions, is normally controlled by .

the capacity of the lube oil pump

the speed of the lube oil pump

the outlet pressure of the lube oil pump

a relief valve

551

In a diesel engine, a cylinder liner should be replaced if it is . I. scuffed II. scored

I only is correct

II only is correct

both I and II are correct

neither I or II are correct

552

In a diesel engine, after ignition of the fuel occurs, but before the piston reaches TDC, there is little change in the cylinder .

volume

pressure

temperature

energy

553

In a diesel engine, an integral liner is one in which the cooling water . I. flows through the cylinder liner jackets II. touches the outer side of the liner

I only

II only

both I and II

neither I nor II

554

In a diesel engine, blow-by .

increases exhaust back pressure

causes excessive crankcase pressure

can only be detected by a compression check

decreases fuel consumption

555

In a diesel engine, blow-by is a result of combustion gases leaking into the crankcase past the .

wrist pin bushings

compression rings

cylinder liner seals

cylinder liner sealing ring

556

In a diesel engine, blow-by is generally the result of worn .

valve guides

oil control rings

valve seats

compression rings

557

In a diesel engine, excessive cylinder liner wear will cause . I. increased blow by II. wear between the piston ring and groove

I only is correct

II only is correct

both I and II are correct

neither I or II are correct

558

In a diesel engine, internal combustion causes the piston to be moved by .

the simple admission of fuel and air into the combustion space only

the pressure of gases developed

specially designed parts connected to a shaft

the concept of reciprocity

559

In a diesel engine, pistons are attached to the crankshaft by .

push rods

piston rods

connecting rods

piston guides

560

In a diesel engine, pistons are attached to the crankshaft by .

push rods

lash adjusters

connecting rods

piston guides

561

In a diesel engine, the function of lubrication oil is to provide .

a film between the shafts and bearings

cooling of the pistons and bearings

for removal of dirt or metal particles resulting from wear

all of the above

562

In a diesel engine, the initial crosshatching of the cylinder liner surface aids in . I. rapid ring seating II. the retention of lube oil

I only is correct

II only is correct

both I and II are correct

neither I or II are correct

563

In a diesel engine, the main bearings are used between the .

connecting rod and the crankshaft

wrist pin and the connecting rod

camshaft and the engine block

crankshaft and the engine block

564

In a diesel engine, the piston compression rings make contact with the . I. back of the ring groove II. bottom of the ring groove

I only

II only

both I and II

neither I nor II

565

In a diesel engine, the spring force required for proper valve operation is determined by .

maximum firing pressure

minimum firing pressure

cam contour

length of the spring

566

In a diesel engine, the time period between fuel injection and ignition is usually defined as .

injection duration

ignition timing

precombustion lag

ignition delay

567

In a diesel engine, the time taken to heat the fuel particles, turn them into vapor, and bring about combustion is called .

injection lag

ignition delay

compression ignition

turbulence lag

568

In a diesel engine, what is the advantage of precombustion chambers over the open type of combustion chamber? I. Precombustion chambers permit coarser fuel atomization. II. Precombustion chambers allow lower fuel injection pressure.

I only

II only

both I and II

neither I nor II

569

In a diesel engine, when installing new piston rings it is important to check . I. ring gap clearance II. side clearance

I only

II only

both I and II

neither I nor II

570

In a diesel engine, when refitting piston rings you should . I. check the ring gap at the smallest diameter of the cylinder II. remove carbon from the ring groove

I only

II only

both I and II

neither I nor II

571

In a diesel engine, which type of wrist pin uses bearings in the piston bosses, but is fixed to the small end of the connecting rod?

Semi-floating

Full floating

Solid

Fixed

572

In a diesel engine, with the valves set to specification, the shape of the cam determines the valve .

point of opening

speed of opening

lift from its seat

all of the above

573

In a direct cylinder admission air starting system, once the engine begins to fire, the air starting check valve illustrated, is closed by .

the starting air pressure

the spring force and cylinder pressure

a valve actuating cam

a pneumatic bellows assembly

574

In a four-stroke/cycle diesel engine, after the completion of the power stroke, the piston will move .

up and draw in a fresh air charge

down to burn off fuel

down to compress the fuel air charge

up and force out the exhaust gases

575

In a four-stroke/cycle diesel engine, piston blow-by can result in increased .

crankcase pressure

compression pressure

scavenge air pressure

exhaust manifold pressure

576

In a four-stroke/cycle diesel engine, the camshaft rotates at .

twice the crankshaft speed

half the crankshaft speed

the same speed as the crankshaft

a speed independent of the crankshaft

577

In a four-stroke/cycle medium-speed diesel engine, fuel injection commences at 10 crankshaft degrees before top dead center. After fuel injection commences, approximately how many degrees will the camshaft rotate before the exhaust valve begins to open?

10- 25

30- 55

60- 80

100- 130

578

In a full floating wristpin, the pin is prevented from sliding against the cylinder walls by .

snap rings

seal welding

a press fitting

a tongue-and-groove

579

In a full flow type lube oil system, the bypass relief valve will lift due to .

a clogged filter element

excessive lube oil pump discharge pressure

excessive lube oil flow

excessively hot lube oil

580

In a hydraulic starting system, oil to the starting motor flows from the .

accumulator

reservoir

hand pump

electric pump

581

In a jerk pump, the amount of fuel that will be forced through the spray nozzle on each upward stroke of the plunger depends on .

the pump supply pressure

the slope of the fuel cam

the position of the helix groove relative to the spill port

the number of sleeve segments engaged with the rack

582

In a large low-speed diesel engine, excessive piston clearance from the cylinder head can be restored by .

decreasing the thickness of the cylinder head gasket

inserting shims between the crankpin bearing box and the connecting rod foot

replacing the complete bearing set

rotating the crankpin bearing until the proper end clearance is obtained

583

In a large main propulsion diesel engine, if an excessive amount of carbon has been found to be forming around the fuel injector nozzle holes, which of the following would correct this condition?

Increase fuel injection pressure.

Increase fuel preheat temperature.

Decrease load limit on the governor.

Increase injector cooling water temperature.

584

In a large slow-speed propulsion diesel engine, the force applied to the crosshead is .

against the crosshead during power stroke and away from the crosshead during the compression stroke

against the crosshead during the compression stroke and away from the crosshead during the power stroke

against the crosshead during the power and compression strokes

away from the crosshead during the power and compression strokes

585

In a large slow-speed propulsion diesel engine, the force applied to the piston is .

against the crosshead during power stroke and away from the crosshead during the compression stroke

against the crosshead during the compression stroke and away from the crosshead during the power stroke

against the crosshead during the power and compression strokes

away from the crosshead during the power and compression strokes

586

In a large slow-speed propulsion diesel engine, the side thrust on the crosshead is the direct result of .

the piston rod acting against the crosshead during the power stroke

the angularity of the connecting rod against the crosshead during the power stroke

the velocity of the crankpin during the power stroke

cylinder pressure acting against the piston crown

587

In a large, low-speed diesel engine the clearance between the piston crown and cylinder head is found to be excessive. In order to correct for this, you should .

build up the piston crown by metal spraying

build up the cylinder head by metal spraying

insert shims between the crankpin bearing box and the connecting rod foot

install a thinner head gasket

588

In a large, slow-speed, main propulsion diesel engine, which of the parts listed is under tension when the engine is running?

Bed plate

Column

Entablature

Tie rod

589

In a medium speed diesel engine, a trunk type piston may be cooled by . I. oil circulation though passages in the piston crown II. heat transfer through piston rings and liner wall

I only

II only

either I or II

neither I or II

590

In a medium-speed marine propulsion engine equipped with direct admission air starting valves, the cylinders without air starting valves fire first because the .

operation is under higher compression

fuel is admitted only to these cylinders during cranking

compression is released during starting by opening the exhaust valve

cylinders are not chilled by the expansion of the starting air

591

In a modern internal combustion diesel engine, the component carrying the torque load of the engine is referred to as the .

bedplate or base

sump or oil pan

cylinder block

frame

592

In a modern internal combustion diesel engine, the load carrying part of the engine is referred to as the .

bedplate or base

sump or oil pan

cylinder block

frame

593

In a normally operating diesel engine, the main source of lubricating oil contamination in the crankcase is a result of the .

metal particles loosened by wear

air when no air cleaners are used

condensation of water vapors

combustion byproducts removed from the cylinder walls

594

In a normally operating diesel engine, the main source of lubricating oil contamination in the crankcase is a result of the .

metal particles loosened by wear

trapped air when no air cleaners are used

condensation of fuel oil vapors

combustion byproducts removed from the cylinder walls

595

In a single acting, four-stroke/cycle diesel engine, the power impulse in an individual cylinder occurs .

once every crankshaft revolution

once every two crankshaft revolutions

once every piston stroke

twice every piston stroke

596

In a single acting, two-stroke/cycle, diesel engine, the power impulse in an individual cylinder occurs .

once every crankshaft revolution

once every two crankshaft revolutions

once every piston stroke

twice every piston stroke

597

In a single acting, two-stroke/cycle, diesel generator engine, the power impulse in an individual cylinder occurs .

once every crankshaft revolution

once every two crankshaft revolutions

once every piston stroke

twice every piston stroke

598

In a single-acting diesel engine, the cylinder liner area that is most difficult to lubricate is the .

major thrust side

minor thrust side

top circumference

bottom circumference

599

In a trunk type diesel engine piston, the thickness of the head or crown is determined by the . I. strength requirement II. heat dissipation requirement

I only

II only

both I and II

neither I nor II

600

In a two-stroke/cycle diesel engine, the camshaft rotates at .

twice the crankshaft speed

half the crankshaft speed

the same speed as the crankshaft

a speed independent of the crankshaft

601

In a two-stroke/cycle, opposed piston, diesel engine, one crankshaft operates several crank angles in advance of the other crankshaft to .

allow the exhaust ports to open and close before the inlet ports close

allow the scavenge ports to open and close simultaneously with the exhaust ports

prevent scavenge air pressure buildup in the cylinders

prevent the exhaust piston from reaching TDC and BDC before the intake piston

602

In a two-stroke/cycle, opposed piston, diesel engine, the lower crankshaft operates several crankshaft degrees in advance of the upper crankshaft to .

allow the exhaust ports to open before the inlet ports

allow the scavenge ports to open and close simultaneously with the exhaust ports

prevent scavenge air pressure buildup in the cylinders

prevent the exhaust piston from reaching TDC before the intake piston

603

In a unit injector, an upper helix and lower helix are machined in the lower part of the plunger for .

facilitating plunger rotation

positioning the control sleeve

accurate metering of the fuel oil

eliminating injection lag

604

In a unit injector, an upper helix and lower helix are machined in the lower part of the plunger for .

facilitating plunger rotation

positioning the control sleeve

variable beginning and variable ending of fuel injection

eliminating injection lag

605

In addition to the main starting air compressor, another air compressor, driven by a separate power source, is installed to .

provide air for engine scavenging

provide air for engine supercharging

supply a backup source of starting air

supply the independent source of reversing air

606

In an actual installation, the flange identified by the letter "U", shown in the illustration, can be directly connected from the brine ejector discharge to the .

saltwater inlet at "I"

upper flash chamber labeled "F"

feed water return labeled "K"

second effect tube bundle

607

In an actual installation, the flange identified by the letter "U", shown in the illustration, can be directly connected from the brine ejector discharge to the .

overboard discharge line

upper flash chamber labeled "F"

feed water return labeled "K"

second effect tube bundle

608

In an actual installation, which of the flanges are connected to the condenser section of the water maker?

I and M

I and Q

Q and R

R and M

609

In an actual installation, which of the flanges are connected to the engine jacket water system for the water maker shown in the illustration?

I and M

I and Q

Q and R

R and M

610

In an auxiliary diesel engine bypass type lubricating oil system, the main lube oil pump forces .

all of the oil used by the engine through a filter

some of the oil used by the engine through a filter

some of the oil used by the engine through a centrifuge

all of the oil used by the engine through a centrifuge

611

In an auxiliary diesel engine, one reason for knurling the piston skirt is to .

improve skirt lubrication

allow for heat expansion

transmit forces evenly

improve the piston seal

612

In an internal combustion engine, which of the devices listed will force the compression rings to seal the compression gases in the space above the piston?

Use of bimetallic piston rings

Ring gap pretensioning

Thermal increase in ring- end clearance

Gas pressure acting against the back of the ring

613

In an operating diesel engine, preignition can be caused by .

excessively late fuel injection

oil in the air charge

water in the fuel

injection continuing after the fuel charge is ignited

614

In an operating diesel engine, the sealing of the cylinder is the result of the compression rings being forced against the cylinder walls by .

oil pressure acting behind the ring

compression pressure acting beneath the ring

ring expansion from the heat of combustion

combustion gas pressure acting behind the ring

615

In an operating diesel engine, which of the following conditions is an indication of a leaking air starting valve?

Noise coming from that air starting valve.

Continuous operation of the starting air compressor.

Zero air pressure in the air starting system.

Overheated starting air pipe to the cylinder head.

616

In an operating diesel engine, which of the following is true concerning a tube and shell type jacket water heat exchanger?

fresh water circulates through the tubes and sea water around the outside of the tubes.

jacket fresh water pressure should always be greater than the sea water pressure.

zinc anodes installed in the heads should always be painted.

all of the above

617

In an opposed piston engine, the term 'crank lead' refers to .

one crankshaft turning faster than the other

the two crankshafts turning in different directions

the piston in one cylinder reaching inner dead center several crankshaft degrees before the other piston

the piston in one cylinder reaching dead center when the other reaches outer dead center

618

In certain cases, a cylinder liner can be refinished rather than replaced. When properly honed, the .

cylinder should be cleaned with kerosene

cylinder liner should have a glazed appearance

liner surface should have a crosshatch pattern

counter bore is slick and smooth

619

In comparing engines of equal horsepower, higher exhaust gas temperatures occur in a/an .

opposed-piston engine

double-acting engine

two-stroke/cycle engine

four-stroke/cycle engine

620

In describing basic diesel engine operation, the term 'event' refers to .

the production of high pressure gases

the removal of expended combustion gases

the admission of air to the cylinder

All of the above

621

In describing engine operation, what does the term 'cycle' mean?

The sequence of events that produce a power pulse.

One rotation of the engine crankshaft.

One stroke of a piston.

All of the above.

622

In diesel engineering practice, the term used to express the ignition quality of a particular fuel is .

cetane number

octane number

ignition index number

volatility point

623

In diesel engines designed with a crosshead, the motion of the piston rod can be described as .

reciprocating at the piston pin, rotary at the crank pin

reciprocating at the crank pin, rotary at the piston pin

straight reciprocation

straight rotation

624

In diesel engines, hydraulic valve lifters are used to .

reduce valve gear pounding

increase valve operating lash

obtain greater valve lift

create longer valve duration

625

In diesel engines, the four basic events (intake, compression, power and exhaust) are performed once in .

two crankshaft revolutions in a two- stroke/cycle engine

two power strokes in a two-stroke/cycle engine

one power stroke in a two-stroke/cycle engine

two piston strokes in a two-stroke/cycle engine

626

In diesel engines, the four basic events (intake, compression, power, and exhaust) are performed once in .

one complete crankshaft revolution in a two-stroke/cycle engine

two crankshaft revolutions in a two- stroke/cycle engine

two power strokes in a two-stroke/cycle engine

two piston strokes in a four-stroke/cycle engine

627

In extremely cold weather, an engine turns over too slowly and fails to start. This problem is most likely the result of .

high fuel oil viscosity

excessive starting air pressure

high lube oil viscosity

low lube oil viscosity

628

In large, low-speed, main propulsion diesel engines, piston ring groove wear usually occurs at the .

top of the ring groove

back of the ring groove

bottom of the ring groove

piston ring end clearance

629

In order for microbiological growths to thrive in a fuel tank it is necessary for .

vanadium to be present

low temperatures to exist

moisture or water to be present

electrolysis to be occurring

630

In order for the self-cleaning fuel oil centrifuge, shown in the illustration, to properly operate during the desludge cycles, the .

bowl locking ring alignment mark should be approximately 1/4 inch to the left of the bowl alignment mark

sliding bowl bottom and operating slide seal rings should be coated with main engine lube oil

sliding bowl bottom and operating slide seal rings should be coated with a high temperature lubricating paste

all of the above

631

In order to determine the fuel pump rack setting for individual fuel pumps on the diesel engine shown in the illustration, you must .

secure the engine and remove the fuel pump crosshead cover

remove the fuel pump crosshead cover and observe the rack setting with the engine running

secure the engine, remove the fuel pump crosshead cover, and compare rack setting to master pump setting

run engine at idle, remove cover, and secure engine while observing rack movement

632

In order to keep excess oil from the intake ports in two- stroke/cycle diesel engines, .

wide compression rings are used

oil rings are located above the piston pin

dense chromium plating is used on all piston rings

oil rings are located near the bottom of the piston skirt

633

In order to maximize the performance of a centrifuge, you can adjust the . I. Number of disks in the stack II. Frequency of shooting the bowl

I only

II only

Both I and II

Neither I nor II

634

In order to reverse the rotation of a two-stroke/cycle loop scavenged, direct reversing, propulsion diesel engine, the cam positions must be changed for the .

starting air and fuel pumps

piston cooling pumps

exhaust valves

all of the above

635

In order to start a large, low-speed, main propulsion diesel engine on high viscosity fuel after an extended shutdown, the .

fuel must be preheated

intake air should be preheated

lube oil outlet temperature should be increased 20 above normal

none of the above

636

In some Bendix drive electric starting systems, the sudden shock of the pinion gear being engaged with the flywheel is absorbed by the .

action of the overrunning clutch

pinion when it engages the ring gear

action of the friction clutch

action of the starter solenoid

637

In some modern large slow speed diesel engines, which of the following is used as the support for the main bearings?

Bedplate

End plates

Tie rods

Sump

638

In the auxiliary diesel engine, shown in the illustration, the .

camshaft rotates at the same speed as the crankshaft

governor is linked to the fuel injection pump by vertical linkage

explosion relief doors are clearly visible on both sides of the crankcase

engine oil filter is outboard of the electric starter

639

In the chart shown in the illustration, a right hand rotation engine has the #9 piston on top dead center; therefore, the #1 piston is .

on the exhaust stroke

on the compression stroke

on the power stroke

at bottom dead center

640

In the common rail system, excessive pressure in the header may be caused by .

improper adjustment of the bypass valve

a dribble in the fuel injection nozzle

insufficient leak off through injection nozzle packing

a malfunctioning injection nozzle

641

In the cylinder head illustrated, the valves are seated by .

gas pressure

valve springs

air pressure

a rocker arm not shown

642

In the cylinder of a diesel engine, fuel is ignited by the .

spark from a plug in the precombustion chamber

electrical discharge from the distributor

heat of compression within the cylinder

heat from the fuel injection nozzle

643

In the device shown in the illustration, the component lettered "A" is the .

heavy phase discharge port

light phase discharge port

dirty oil input port

seal water input port

644

In the diesel engine illustrated, what part is under compression when firing is taking place in a particular cylinder?

Tie rod

Piston rod

Piston rod nut

Lubrication telescopes

645

In the diesel engine shown in the illustration, the space below the cylinder liner lower seals is subjected to .

scavenge air pressure

lube oil pressure

cooling water pressure

crankcase pressure

646

In the diesel engine shown in the illustration, what part is under compression when the cylinder is firing?

Tie rod

Piston rod

Turbocharger

Lubrication telescopes

647

In the diesel engine shown in the illustration, which of the following statements is true?

The camshaft turns at the same speed as the crankshaft.

The engine utilizes dry type cylinder liners.

The engine cylinder position shown is at the end of its exhaust cycle.

All of the above.

648

In the diesel engine shown in the illustration, which of the following statements is true?

The camshaft turns at half the speed of the crankshaft.

The engine utilizes wet cylinder liners.

The intake valves are operated with a valve bridge.

All of the above.

649

In the engine shown in the illustration, the part labeled "W" is cooled by .

seawater

air

lube oil

convection

650

In the illustrated diesel engine, which label points to the piston?

K

3

4

6

651

In the illustrated engine, the fuel camshaft gear drive housing is indicated as letter .

B

F

G

Z

652

In the illustrated engine, the fuel camshaft gear drive housing is letter .

C

D

E

F

653

In the illustrated engine, the main camshaft controls the timing of which of the following components?

Intake valves

fuel pumps

exhaust valves

all of the above

654

In the illustrated polar timing diagram for a four-stroke cycle diesel engine, relative to crank degrees of travel with respect TDC or BDC as appropriate, when does the intake valve open?

75 degrees before TDC

85 degrees before TDC

45 degrees after BDC

55 degrees before BDC

655

In the illustrated polar timing diagram for a four-stroke diesel engine, relative to the number of crank degrees before or after TDC or BDC as appropriate, when does the intake valve close?

75 degrees before TDC

85 degrees after TDC

45 degrees after BDC

55 degrees before BDC

656

In the illustration shown, if a crankcase explosion occurs in a diesel engine, which of the following will occur?

Piece #2 will move to the right

Piece #5 will rotate counterclockwise as viewed from the right

Piece #7 will move to the left

Spring #11 will be compressed

657

In the illustration shown, moving the component labeled "E", further to the left, will result in .

an increase in the cylinder mean effective pressure

a shorter fuel injection cycle

a greater quantity of fuel injected

an increase in fuel pump delivery pressure

658

In the illustration shown, under what conditions would valves "2" and "3" be closed and valve "6" be opened?

When the HFO centrifuges are being run as separators and clarifiers respectively.

When the HFO purifier is being run as DO purifier.

When the DO purifier is being is being run as the HFO purifier.

When the HFO purifiers are being run in parallel.

659

In the illustration, pieces #31 and #29, have 16 and 55 teeth respectively. In order to start the engine, the Bendix drive must turn 3000 RPM. Therefore, the air motor assembly must rotate at .

872.72 RPM

5516.3 RPM

10312.5 RPM

26400 RPM

660

In the large slow-speed main propulsion diesel engine shown in the illustration, the part labeled "G" is the .

lube oil pump

fuel oil pump

jacket water pump

crankcase exhaust fan

661

In the large slow-speed main propulsion diesel engine shown in the illustration, the part labeled "G" is the .

jacket water pump

lube oil pump

fuel oil pump

crankcase exhaust fan

662

In the large, slow-speed diesel engine frame shown in the illustration, firing forces are absorbed by the ,

crosshead guide rails

tie rods

entablature

column

663

In the Otto cycle, the fuel/air mixture is ignited at what point and by what means?

At TDC by heat generated by compression.

Just before TDC by heat generated by compression.

Just before TDC by spark ignition.

At TDC by spark ignition.

664

In the overrunning clutch shown in the illustration, if "A" was rotating faster than "B", the clutch is considered to be .

engaged

disengaged

worn out

stripped

665

In the past, the interior sides of most centrifugal purifier bowls were straight. However. the interior side of the bowl shown in the illustration, as compared to a straight interior vertical side bowl, is designed to .

allow a greater volume of sealing water to be carried

assist in the self- cleaning process

assist in reducing the thickness of the emulsion interface

eliminate the need for a discharge ring

666

In the pressure-volume diagram shown in the illustration, fuel injection occurs at point .

c

d

e

f

667

In the pressure-volume diagram shown in the illustration, the atmospheric pressure line is indicated by line .

A

B

C

de

668

In the pressure-volume diagram shown in the illustration, curve 'A-d' indicates .

fuel injection after dribble

combustion at approximately constant pressure

opening of exhaust valves

start of fuel injection

669

In the pressure-volume diagram, shown in the illustration, what is indicated to have occurred by the line connecting points "d" and "e"?

The combustion gases have expanded.

The crankshaft has rotated 90.

Pressure and volume have increased.

The fuel/air charge is compressed.

670

In the pressure-volume diagram, shown in the illustration, what occurs between points "e" and "f"?

The exhaust valve closes.

Exhaust blow down occurs.

Pressure in the cylinder increases.

Volume in the cylinder decreases.

671

In the pressure-volume diagram, shown in the illustration, what occurs between points "e" and "f"?

The exhaust valve closes.

The intake ports close.

Pressure in the cylinder decreases.

Volume in the cylinder decreases.

672

In the pressure-volume diagram, shown in the illustration, the volume line is divided into 16 units indicating .

a cylinder volume of 166 cubic inches

16 of crankshaft motion between lines A and B

a 16 to 1 compression ratio

a 15 to 1 compression ratio

673

In the pressure-volume diagram, shown in the illustration, the volume line is divided into 16 units indicating .

a cylinder volume of 166 cubic inches

16 of crankshaft motion between lines A and B

a 16 to 1 compression ratio

compression pressure is 1600 PSI

674

In the slow speed diesel engine shown in the illustration, the part labeled "E" is the .

high pressure lube oil line

low pressure lube oil line

high pressure fuel line

low pressure fuel line

675

In the starting process of a diesel engine, the main object is to attain the compression conditions sufficient to .

turn the flywheel

reduce friction

overcome inertia

ignite the fuel

676

In the theoretical diesel cycle, shown in the illustration, which of the listed conditions normally takes place between points "3" and "4"?

Compression

Combustion-constant volume

Combustion-constant pressure

Expansion

677

In what figure of the illustration does the crosshead experience the greatest side thrust?

Figure 1

Figure 2

Figure 5

Figure 6

678

Incomplete combustion in a running diesel engine can cause piston rings to become stuck as a result of .

residual carbon deposits

lube oil viscosity breakdown

uneven heat expansion of the rings

uneven heat expansion of the piston

679

Incorrect timing of the fuel injection system is similar to the effects of poor .

metering of the fuel flow to the injector

control of the rate of fuel injection

control of atomization of the fuel

distribution of the fuel throughout the combustion chamber

680

Increasing the compression ratio of a diesel engine while maintaining the designed rate of fuel flow will result in .

increased horsepower

reduced efficiency

increased heat loss

lower cylinder pressures

681

Increasing the compression ratio of a diesel engine while maintaining the designed rate of fuel flow will result in .

increased horsepower

reduced mean effective pressure

decrease in heat loss

lower cylinder operating temperatures

682

Increasing the compression ratio of a diesel engine while maintaining the designed rate of fuel flow will result in .

reduced efficiency

increased thermal efficiency

increased heat loss

lower cylinder pressures

683

Increasing the load on an engine using a double-helix type injection pump varies the effective stroke of the pump to start .

earlier and end later

later and end earlier

and end later

and end earlier

684

Indirect cooling of fuel injector nozzle holders for diesel engines is accomplished primarily by .

heat conduction into the injected fuel oil

heat conduction into the water jacket wall

water circulation through passages in the holder

fuel oil circulation through passages in the holder

685

Injection lag can be caused by .

improper timing of the intake valves

setting of the pump plunger

compressibility of the fuel

position of the needle valve

686

Injection lag in a diesel engine may be caused by .

a change in the cetane number of the fuel

a decrease in the air temperature

a decrease in compression pressure

the flexibility of high pressure fuel lines

687

Injection pressure in a common rail fuel system is controlled by .

engine speed

varying the fuel pump piston stroke

varying the injector needle valve clearance

a pressure regulating bypass valve

688

Injection pressure in a common rail fuel system is controlled by .

engine speed

varying the fuel pump piston stroke

varying the injector needle valve clearance

a bypass valve

689

Injectors for use with heavy fuel oil may be internally cooled by either water or light oil to .

prevent heat corrosion to internal components

increase fuel delivery rate and economy

prevent preignition

avoid carbonization of the nozzle tips

690

Insufficient end clearance on newly fitted piston rings in a diesel engine will cause the rings to .

jam in the least worn part of the cylinder liner when the rings expand

jam in the most worn part of the cylinder liner when the rings expand

show excessive wear on the top face

show excessive wear on the bottom face

691

Insufficient piston cooling for a large, low-speed, main propulsion diesel engine burning heavy fuels, can result in .

high temperature corrosion and burning of piston crown metal

dangerous thermal expansion of the piston skirt

excessive crosshead temperatures

change in fuel cetane number

692

Integral cylinder liners constructed as part of the cylinder block, are characterized by which of the following disadvantages?

They conduct heat poorly.

They must operate with lower mean effective pressures.

They cannot be replaced.

They require special tools for removal.

693

Integral water jacket liners use O-rings near the bottom of the liner. These O-rings serve to .

form a water seal between the liner and engine block

allow for slight misalignment of the liner

prevent the escape of lubricating oil from the crankcase

ensure proper temperature flow between the liner and engine block

694

Intercoolers installed on starting air compressors, reduce the possibility of .

dust entering the first stage

lube oil carbonization

discharge pulsations

interstage vapor lock

695

Intercoolers installed on starting air compressors, reduce the possibility of .

dust entering the first stage

overheating the first stage

overheating the second stage

interstage vapor lock

696

Irregular engine speed in a diesel can be caused by .

low cooling water temperature

low fuel viscosity

high injection pressure

binding in the fuel control linkage

697

Irregular engine speed in a diesel generator can be caused by .

high generator load

low fuel viscosity

high injection pressure

binding in the fuel control linkage

698

It is easier to replace a dry cylinder liner than a wet one because .

of the thin wall thickness

honing makes it easier to maintain the desired oil film

water seals are not required

heat transfer from the liner to the engine block is not a critical factor

699

Item "10" shown in the illustration is used to .

prevent damage to device "9" by reducing turbulence

cancel the effects of improper regulation developed by device "11"

regulate flow from the drain pump

direct the flow from the distillate pump

700

Item "17" in the illustration is the dipstick. When should the length of the dipstick be changed?

In most situations this would never be done.

If the operating oil level of the engine is consistently below normal, it will be necessary to use a longer dip stick.

When changing the oil in an operating engine, it may become necessary to use a longer stick to obtain the exact location of the oil level at all times.

If sludge buildup on the bottom of the pan becomes excessive, it will become necessary to shorten the dipstick to accommodate for the false oil level reading.

701

Item "6" shown in the illustration would be identified as a .

sleeve bearing

spring bearing

thrust shoe

bearing collar

702

Item "7" shown in the illustration is identified as a .

magnetic pickup used to sense shaft speed

dip stick

thermometer

shaft deflection indicator

703

Item "M" shown in the illustration is the .

salt water inlet

feed water inlet

jacket water inlet

brine water outlet

704

Item "O" of the device shown in the illustration is the .

fair flow nut

inlet directional guide

spindle nut

impeller locking device

705

Item #16 of the piston shown in the illustration is a/an .

thrust plate or thrust washer

piston carrier pin

oil drain passage

bearing insert tang

706

Item labeled "L" as shown in section 6 of the illustration is identified as the .

air filter

after cooler

air blower

exhaust gas turbine

707

Item labeled "R" as shown in section 6 of the illustration is identified as the .

after cooler

non return scavenge valve

air filter

exhaust manifold

708

Item labeled "S" as shown in section 4 of the illustration is identified as the .

exhaust port

intake port

after cooler

scavenging valve

709

Jacket water heaters are used on diesel engines to .

help the engine start easier in cold weather

maintain the proper jacket water pH

maintain the proper expansion tank water level

keep the engine room warm

710

Keel coolers fouled with marine growth, will result in .

higher raw water temperatures

higher jacket water temperatures

a malfunctioning thermostat

higher fuel temperature

711

Late fuel injection occurring at, or after TDC in a diesel engine is indicated by excessive exhaust smoke and .

low exhaust temperature

low firing pressure

fuel knock in each cylinder

mechanical knock in each cylinder

712

Late fuel injection timing is indicated by .

lower than normal cylinder pressure and low exhaust temperature

lower than normal cylinder pressure and high exhaust temperature

higher than normal cylinder pressure and low exhaust temperature

higher than normal cylinder pressure and high exhaust temperature

713

Late fuel oil injection in a diesel engine can result in .

fuel knock

increased power

low compression pressure

high exhaust temperature

714

Line "K" shown in the illustration is the .

distillate pump suction

brine eductor suction

brine eductor inlet

feed water inlet

715

Line "P" in the illustration is called the .

exponential line

line of maximum horsepower

line of maximum speed

propeller curve

716

Line "P" in the illustration is the .

exponential line

line of maximum horsepower

propeller curve

line of maximum efficiency

717

Load control on a diesel engine is accomplished by .

regulating the speed of the turbocharger

regulating the amount of fuel admitted to the engine

regulating the speed of the fuel oil transfer pump

changing engine timing

718

Loss of lubricating oil pressure to the main propulsion diesel engine will actuate a/an .

overspeed trip

audible/visual alarm

the ships/boats general alarm

reserve oil storage tank

719

Low compression in a diesel engine can be caused by .

clogged coolant passages

a leaking cylinder head gasket

low fuel oil pressure

worn or broken cylinder liner sealing rings

720

Low compression in a diesel engine could be caused by .

worn or broken cylinder liner sealing rings

high cooling water temperature

worn or broken piston rings

low fuel oil pressure

721

Low compression in a diesel engine could be caused by .

worn or broken wet cylinder liner sealing rings

high fuel injection pressure

worn or broken piston rings

low fuel oil booster pump pressure

722

Low compression pressure in a diesel engine can be caused by .

improperly seating intake valves

leaking cylinder liner seal rings

late fuel injection timing

carbon deposits on the piston

723

Low compression pressure in a diesel engine cylinder can be caused by .

carbon deposits on the piston crown

leaking cylinder liner seal ring

poor quality fuel

worn crankshaft and crankpin bearings

724

Low compression pressure in a diesel engine is caused by .

low water in the expansion tank

improperly seated valves

low fuel oil pressure

worn or broken cylinder liner sealing rings

725

Low compression pressure in a diesel engine may be the result of .

insufficient fuel supply due to fuel pump valves sticking or leaking

excessive mechanical clearance between the piston crown and cylinder head

excessively worn fuel pump plunger

excessive exhaust back pressure

726

Low cylinder compression pressure and a high exhaust temperature may indicate .

early fuel injection timing

leaking valves

a continuously open scavenge air port

low cooling water temperature

727

Lube oil accumulating in the cooling water system of a diesel engine will result in .

lube cooler failure

poor heat transfer

mechanical lubricator failure

camshaft seizure

728

Lube oil cannot be efficiently filtered if its .

viscosity is too low

temperature is too low

pump discharge pressure is higher than the system's pressure

pump capacity is greater than the system's needs

729

Lube oil contamination will increase due to normal wear of engine components as a result of .

abrasive particles

metallic oxides

corrosive acids

any or all of the above

730

Lube oil filters can be used to remove most contaminants from lube oil. Which of the contaminants listed would remain in the lube oil after filtering?

Acid sludge

Fuel oil

Sediment

Water

731

Lube oil filters remove contaminants from oil more efficiently if the oil being filtered is .

heated to reduce viscosity

cooled to increase viscosity

pumped rapidly through the filter

pumped through the filter under high pressure

732

Lube oil filters remove contaminants more efficiently if the oil being filtered is .

under high pressure

under low pressure

heated to reduce viscosity

cooled to increase viscosity

733

Lube oil in the fresh water cooling system of a diesel engine may result from a .

camshaft seizure

lube oil pump failure

lube oil cooler failure

lube oil sump overflow

734

Lube oil pumps taking suction from the sump of most small marine engines are usually .

diaphragm type

centrifugal type

positive displacement type

eductor type

735

Lube oil pumps taking suction from the sumps of marine diesel engines are usually classified as .

diaphragm type

centrifugal type

positive displacement type

eductor type

736

Lubricating oil is supplied to the crankpin bearings in a marine diesel engine by .

internal crankshaft passages

immersion in oil

splash lubrication

injection lubrication

737

Lubricating oil systems for diesel engine journal bearings are usually lubricated by which of the following types of lubricating oil systems?

Splash

Gravity

Pressure

Bypass

738

Lubricating oil used in a diesel engine serves to .

reduce the wear of bearing surfaces

cool the bearing surfaces

assist in sealing bearing surfaces

all of the above

739

Lubricating oil viscosity in an operating diesel engine can be reduced by .

increasing cooling water flow

increasing lube oil flow

dilution by fuel oil

adding SAE 70 oil

740

Lubricating systems for diesel engines are usually designed to first provide a supply of lube oil to the engines .

crankpin journals

main bearings

piston crowns

cylinder wrist pins

741

Lubrication for the main reduction gears used with diesel engines is usually supplied by .

oil from the main engine sump

an independent lube oil system

the stern bearing head tank

the stern bearing sump tank

742

Maintaining the proper fuel oil temperature will result in .

the elimination of valve wear

improved atomization

a decrease in cylinder blow-by

a decrease in cylinder mean effective pressure

743

Many cast iron pistons are designed with heat dams, which serve to .

keep piston crown temperatures elevated for smoother combustion

reduce the possibility of overheating the top compression ring

help retain the heat of compression to prevent ignition delay

help retain the heat of compression to prevent combustion knock

744

Many diesel engines have pistons with concave heads to .

decrease air turbulence and improve fuel mixing

increase air turbulence and improve fuel mixing

prevent fuel afterburning when injection ends

prolong fuel afterburning when injection ends

745

Many lube oil filters have pressure gages installed on both the inlet and outlet in order to indicate the pressure drop across the filter. In normal operation, the pressure drop will .

slowly increase

slowly decrease

remain the same

have no effect on filter operation

746

Marine auxiliary diesel engine starters utilizing Bendix drive gear are powered by an electric starting motor or .

hydraulic starting motors

explosive cartridge motors

inertial flywheel motors

compound gear motors

747

Maximum lube system operating pressure for a diesel engine is normally regulated by a/an .

orifice in the pump suction

special filter design

pressure drop through the filter

relief valve

748

Maximum rated horsepower of a diesel engine is attained .

when the engine RPM is pulled down by overload

at rated engine RPM

at 50% of rated engine RPM

at the speed of maximum torque

749

Maximum rated horsepower of a diesel engine should be attained .

when the engine RPM is pulled down by overload

at rated engine RPM

at 50% of rated engine RPM

at the speed of maximum torque

750

Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are .

operated manually once each hour

operated until the engine has started

placed into operation only at maximum load

adjustable to meet lubrication requirements

751

Microbiological growths in marine fuel are a common occurrence that can be .

extremely detrimental to equipment and operating processes

prevented by maintaining higher storage temperatures

removed from emulsified fuel oil during the centrifuging processes

All of the above are correct.

752

Misfiring in a diesel engine at light loads can be caused by .

high lube oil temperature

low lube oil temperature

excessive cylinder cooling

high air injection pressure

753

Mist detectors used on large low-speed and medium speed main propulsion diesel engines monitor and check for the presence of .

fuel oil vapor at the sludge tank vent

unburned fuel vapors in the scavenge air receiver

lube oil vapors in the crank case

lube oil vapors in the engine room

754

Modern marine diesel engines equipped with mechanical fuel injection operate on a combustion cycle which is .

entirely constant pressure

entirely constant volume

a combination of constant volume and constant pressure

a combination of constant temperature and constant pressure

755

Modern marine diesel engines equipped with mechanical fuel injection operate on a combustion phase within the cycle which is .

entirely constant pressure

entirely constant temperature

a combination of constant volume and constant pressure

a combination of constant temperature and constant pressure

756

Modern marine diesel engines using mechanical fuel injection, operate on a combustion cycle which is .

a combination of constant volume and constant pressure

a combination of constant temperature and constant pressure

entirely constant pressure

entirely constant volume

757

Most fuel injection nozzles are opened by .

fuel oil pressure

a cam operated follower

a spring-loaded pressure plate

timing gears keyed to the crankshaft

758

Most large main propulsion diesel engines use a duplex lube oil strainer to .

decrease the time required between cleanings

remove all large and small foreign objects

ensure a positive flow of oil at all times

ensure that all lube oil has been treated twice

759

Most large main propulsion diesel engines use duplex lube oil strainers to .

decrease the time required between cleanings

remove water contamination

ensure a positive flow of oil at all times

ensure that all lube oil has been treated twice

760

Most practical diesel engines today operate on a cycle which is a combination of the Diesel and Otto cycles. In this process, compression ignition .

begins on a constant volume basis

begins on a constant pressure basis

ends on a constant volume basis

begins and ends on a constant volume basis

761

Most type(s) of microbiological growths in fuel are .

bacteria

fungi

yeasts

All of the above

762

Motor vessels usually have independent lube oil systems for main engine and main reduction gears because .

coolers are not needed for the gear system

contaminants produced by the engine could harm the reduction gears

non-additive oils are used in the main engine system

different type centrifuges are required for the main engine and reduction gear lube systems

763

Movement of the control rack of the fuel injector shown in the illustration, changes the .

fuel injection rate

fuel injection cycle

quantity of fuel injected

fuel pump delivery pressure

764

Movement of the pump control rack in a fuel injection system using individual plunger-type pumps .

changes the position of the fuel inlet ports

changes the length of the pump stroke

varies the quantity of fuel delivered

varies the compression of the delivery valve spring

765

Oil control rings are designed with slotted holes to .

decrease ring contact area and cut down heat transfer

decrease contact pressure between ring and cylinder wall

increase contact pressure between ring and cylinder wall

permit excess oil to drain back to the sump

766

Oil control rings function to .

allow proper lubrication of cylinders and compression rings

reduce the amount of lube oil burned in the combustion chamber

scrape excess lube oil from the liner on the down stroke

all of the above

767

Oil control rings used in two-stroke/cycle diesel engines are located near the bottom of the piston skirt in order to .

increase the liner area covered by the oil film

maintain an oil film on the lower liner where scuffing is prevalent

keep excess oil away from intake and exhaust ports

help cushion piston skirt side thrust by providing a hydrodynamic oil wedge

768

Oil oxidation as a result of excessively high lube oil temperature, is harmful to a diesel engine because .

oil foaming will always occur

large quantities of oil are consumed

lube oil viscosity always increases when the oil temperature is above normal

corrosive by-products are usually formed

769

Oil oxidation, as a result of excessively high lube oil temperature, is harmful to a diesel engine because .

oil foaming will occur

large quantities of oil are consumed

lube oil viscosity is always decreased

corrosive by-products are usually formed

770

On a diesel engine equipped with individual jerk type fuel pumps, adjustments should be made to the tappets (push rods) of the pumps to .

equalize effective delivery strokes

regulate combustion pressures

regulate exhaust temperatures

change from light to heavy fuel

771

On a diesel engine with direct-cylinder admission air starting, a leaking air starting valve would be indicated by .

an overheated starting air supply pipe

excessive smoke from the engine exhaust

carbon deposit on the exhaust valves

early fuel ignition

772

On a diesel engine, using a distributer type air starting system, that is not running, which of the following methods may be used to detect leaking air starting valves?

Open the cylinder test cocks and check for blowing air.

Check the position of the air start valve cams.

Stop the air compressor and check for pressure drop throughout the system.

Feel each air supply line to see which is warm from leaking air.

773

On a large low-speed main propulsion diesel engine, lower main bearing wear is usually measured by using a/an .

dial indicator

outside caliper

bridge gage

tram rod

774

On a main propulsion diesel engine, the instrument shown in the illustration would normally be attached to the .

cylinder blow down valve

exhaust manifold

turbocharger after cooler

engine crankcase

775

On a medium-speed main propulsion diesel engine, the crankpin or crank journal bearings receive lubricating oil from .

a spindle lubricator

an oil jet

internal splashing

drilled passages in the crankshaft

776

On an opposed-piston engine, increasing the lower crank lead will result in which of the listed operating conditions?

Exhaust ports will uncover after the air intake ports

Exhaust ports will uncover before the air intake ports

Duration of air intake will increase

Duration of air intake will decrease

777

On board supply vessels, a centrifuge is normally used to purify .

cooling water

fuel oil

sea water

diesel intake air

778

On most modern diesel engines, the main and connecting rod bearings receive their lubricating oil by .

banjo feed

splash feed

gravity feed

pressure feed

779

On small diesel engines, a noticeable decrease in the time interval between the replacement of the lube filter cartridge indicates .

piston ring blow-by

dirty air filter

excessive oil pressure

excessive oil temperature

780

On the cylinder indicator diagram illustrated, the dotted line indicated as "L" is describing the .

cylinder pressure without injection

firing pressure at 90 degrees crank angle