|
C |
Lube oil pumps
taking suction from the sump of most small marine engines are usually __________. |
diaphragm type |
centrifugal type |
positive displacement
type |
eductor type |
|
B |
Auxiliary diesel
engines can be automatically shut down as a result of __________. |
low lube oil temperature |
low lube oil pressure |
high exhaust temperature |
high cooling water
pressure |
|
C |
When a generator
diesel engine is operated at partial load, as compared to full load, a decrease
will occur in the average __________. |
piston speed |
fuel injection
pressure |
combustion pressure
on the power stroke |
compression pressure
on the compression stroke |
|
A |
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 |
|
D |
What is the best
way of stopping an over speeding diesel engine? |
Disconnect the
battery cables from the starting motor. |
Drain the hydraulic
fluid from the governor sump. |
Block the flow
of cooling air to the radiator. |
Secure the fuel
supply and block the air intake |
|
C |
Which of the listed
conditions will result in the failure of an auxiliary diesel engine to shut
down? |
Supplying high
temperature inlet air. |
Maintaining a
high exhaust back pressure. |
Lube oil entering
in the air intake manifold. |
Carbon buildup
on the over speed pawl. |
|
A |
In the auxiliary
diesel engine, shown in the illustration, the __________. Illustration MO-0006 |
governor is linked
to the fuel injection pump by vertical linkage |
explosion relief
doors are clearly visible on both sides of the crankcase |
camshaft rotates
at the same speed as the crankshaft |
engine oil filter
is outboard of the electric starter |
|
B |
Which of the following
test indicators should be considered the most significant factor in determining
as to whether or not a diesel generator's lube oil should be drained and
renewed? |
The oil appears
black in color. |
An extremely high
neutralization number. |
An extremely low
precipitation number. |
An increase in
flash point. |
|
B |
The valve cam
slope angle determines the __________. |
engine torque
characteristics |
acceleration rate
of valve opening and closing |
engine fuel efficiency |
diameter of intake
and exhaust valves |
|
D |
When two cams
of the same diameter, one with tangential flanks and the other with convex
flanks are compared, the cam with tangential flanks will cause___________. |
less valve seat
wear |
greater valve
lift |
more abrupt valve
action |
less valve gear
wear |
|
C |
The part labeled "G",
as shown in the illustration, is a __________. Illustration MO-0040 |
connecting rod
cap |
bearing shell |
connecting rod
bushing |
piston bushing |
|
C |
In diesel engines,
hydraulic valve lifters are used to __________. |
obtain greater
valve lift |
create longer
valve duration |
reduce valve gear
pounding |
increase valve
operating lash |
|
D |
The intake and
exhaust valves used in a diesel engine are returned to their seats by __________. |
combustion pressure |
push rod pressure |
exhaust pressure |
spring force |
|
A |
Before any auxiliary
diesel engine hydraulic starting system is opened for servicing or repair,
you must __________. |
bleed off all
hydraulic pressure from the system |
place all control
levers in the 'HOLD' position |
block all hydraulic
hoses using high pressure covers |
ensure that the
hydraulic fluid reservoir is full |
|
A |
The service life
of a worn aluminum piston for an auxiliary diesel, for which no spares are
readily available, can be extended by __________. |
knurling the piston
skirt surface |
increasing the
dimensions of the ring land grooves |
building up the
piston skirt with a liquid epoxy material and then remachining |
turning down the
piston skirt to concentric values |
|
A |
In an auxiliary
diesel engine, one reason for knurling the piston skirt is to __________. |
improve skirt
lubrication |
transmit forces
evenly |
allow for heat
expansion |
improve the piston
seal |
|
A |
A four-stroke
cycle auxiliary diesel engine fuel cam has shifted from its original position
during maintenance. To ensure correct timing of the fuel pump, the intake
and exhaust valves should be in what position when approaching top dead
center for injection? |
Intake and exhaust
valves closed |
Exhaust valve
open, intake valve closed |
Intake and exhaust
valves open |
Intake valve open,
exhaust closed |
|
A |
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 __________. |
overheated motor
windings |
ring gear with
broken teeth |
low lube oil viscosity |
low compression
pressure |
|
B |
In a four-stroke/cycle
diesel engine, badly worn intake valve guides can cause excessive __________. |
cooling water
temperatures |
lube oil consumption |
exhaust pressure |
exhaust temperatures |
|
D |
On small diesel
engines, a noticeable decrease in the time interval between the replacement
of the lube filter cartridge indicates __________. |
excessive oil
temperature |
excessive oil
pressure |
dirty air filter |
piston ring blow-by |
|
A |
A diesel engine
may fail to start when being cranked, due to __________. |
insufficient compression |
high cetane number |
low lube oil viscosity |
high lube oil
pressure |
|
C |
High exhaust temperature
and black smoke exhausting from an auxiliary diesel engine can be caused
by __________. |
plugged fuel nozzle
holes |
excessive compression
pressure |
engine overload |
low combustion
temperature |
|
A |
One remedy for
a high firing pressure, in addition to a high exhaust temperature in one
cylinder of a diesel engine, is to __________. |
adjust the fuel
rack |
retard fuel injector
timing |
reduce fuel booster
pump pressure |
increase scavenge
air pressure |
|
D |
Starting aids
such as glow plugs, are installed on __________. |
large, direct
drive diesel engines |
diesel engines
designed to burn residual fuels |
medium-speed,
four-stroke/cycle diesel engines |
small diesel engines
utilizing electric starting equipment |
|
D |
Precombustion
chambers, and energy cells in high-speed, small bore diesel engines all
serve to increase __________. |
firing pressure |
ignition quality
of fuel |
fuel/air ratio
during compression |
turbulence |
|
A |
Which of the combustion
chambers shown in the illustration is referred to as an "energy cell"
used in some small diesel engines? Illustration MO-0068 |
A |
B |
C |
D |
|
B |
The purpose of
the energy cell, or air cell, is to __________. |
cause auto ignition
in the cell rather than in the main combustion chamber |
create a high
turbulence within the main combustion chamber |
allow the spray
to hit the piston rim rather than the cooler cylinder wall |
make a blast in
the main chamber prior to the piston expansion stroke |
|
B |
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 |
|
A |
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 |
|
D |
Open combustion
chambers are designed to __________. |
eliminate carbon
buildup |
improve piston
cooling |
prevent air charge
turbulence |
provide proper
fuel/air mixing |
|
B |
What type of marine
engine has a fuel nozzle and combustion chamber located between two pistons
in a common cylinder liner? |
Horizontal reciprocating |
Vertical opposed
piston |
Single acting
in-line cylinder |
Double acting
in-line cylinder |
|
D |
Pre-combustion
chambers differ from turbulence chambers in that pre-combustion chambers
__________. |
allow fuel injection
directly into the space above the piston |
do not contain
the fuel injector nozzle tip |
contain the major
portion of the total clearance volume |
contain a smaller
portion of the total clearance volume |
|
D |
Starting aids,
such as glow plugs, are usually installed on __________. |
large, direct
drive diesel engines |
diesel engines
designed to burn residual fuels |
medium-speed,
four-stroke/cycle diesel engines |
small diesel engines
with electric motor starters |
|
C |
The combustion
of fuel for the illustrated engine is initiated by __________. Illustration
MO-0020 |
fuel injection
provided by a unit injector |
individual Bosch
fuel pumps |
a spray of fuel
into a turbulence combustion chamber |
fuel sprayed into
an energy cell |
|
A |
Which of the listed
types of pre-combustion chambers is used in the diesel engine shown in the
illustration? Illustration MO-0007 |
Turbulence chamber |
Energy cell |
Common rail |
Open type |
|
D |
The desirable
properties of a marine fuel oil should include __________. |
low heating value
and high sulphur content |
low flash point
and high viscosity |
high flash point
and high viscosity |
high heating value
and low sulphur content |
|
A |
With respect to
diesel fuel, the ease with which a cold engine will start is dependent upon
the __________. |
ignition quality
of the fuel |
high heating value
of the fuel |
amount of carbon
residue after combustion |
internal flow
resistance in the injectors |
|
D |
The ignition quality
of diesel fuel becomes LESS critical as __________. |
lube oil additives
are increased |
designed piston
speeds are increased |
designed injection
pressures are decreased |
designed engine
speeds are decreased |
|
B |
The cetane number
rates fuels for diesel engines according to its __________. |
antiknock characteristics |
ignition qualities |
rates of vaporization |
viscosity |
|
C |
Which of the following
statements is true concerning the cetane number of diesel fuel? |
The cetane number
affects the amount of injection lag. |
The cetane number
is an indication of the fuel's viscosity. |
Ignition lag is
reduced with fuels having a high cetane number. |
The cetane number
is of little significance in the combustion process. |
|
B |
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 |
|
C |
If a particular
liquid has a specific gravity of .96kg/dm3 at 77°F, what will be the specific
gravity of the liquid, as determined from the graph shown in the illustration,
if the temperature is increased to 167°F? Illustration MO-0113 |
.920 kg/dm3 |
.915 kg/dm3 |
.925 kg/dm3 |
.910 kg/dm3 |
|
B |
The minimum fuel
oil delivery pressure required for efficient injection depends primarily
on the __________. |
degree of cylinder
air turbulence |
maximum pressure
in the engine cylinders during injection |
quantity of the
fuel to be injected |
duration of the
injection delay period |
|
C |
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 |
|
A |
The degree of
fuel atomization in a diesel engine cylinder depends primarily on __________. |
the size of the
holes in the fuel nozzle |
timing of the
pump |
supply pressure
to the pump |
shape of the combustion
chamber |
|
A |
The purpose of
the delivery check valve used in a diesel fuel injection jerk pump is to
__________. |
assist in a quick
cutoff of fuel injection |
allow oil backflow
from the injector to the helix |
reduce fuel oil
pressure between injection strokes |
meter the quantity
of fuel delivered |
|
B |
Regarding the
fuel injector shown in the illustration, the purpose of piece #38 is to
__________. Illustration MO-0059 |
adjust the fuel
rack spring tension |
filter the fuel |
maintain fuel
pressure at a preset level |
relieve excess
fuel pressure to the suction side of the pump |
|
C |
The amount of
fuel delivered by a unit injector is controlled by the __________. |
camshaft |
main spring |
rack position |
engine speed |
|
C |
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 |
|
B |
The control rack
to a unit injector regulates fuel delivery by __________. |
altering spring
tension on the plunger |
rotating the plunger
and position of the helix |
regulating the
lift of the check valve |
altering the actual
length of the plunger stroke |
|
A |
Which type of
diesel engine fuel nozzle is shown in the illustration? Illustration MO-0059 |
Multi-hole |
Open |
Self-cleaning |
Pintle |
|
B |
The component
shown in the illustration would be identified as a __________. Illustration
MO-0097 |
slow speed engine
cylinder liner lubricator |
slow speed engine
fuel pump |
centrifugal flyweight
governor |
injector cooling
system pump |
|
B |
The component
identified as item #15 is used to __________. Illustration MO-0016 |
test injector
popping pressure |
stop fuel delivery
to the injector |
advance fuel pump
timing |
increase the fuel
pump delivery pressure |
|
A |
In the large slow-speed
main propulsion diesel engine shown in the illustration, the part labeled "G"
is the __________. Illustration MO-0003 |
fuel oil pump |
jacket water pump |
crankcase exhaust
fan |
lube oil pump |
|
A |
According to the
illustration, initial timing of fuel injection into the cylinder is controlled
with the component that is identified as the letter __________. Illustration
MO-0097 |
C |
H |
K |
I |
|
A |
According to the
illustration, fuel cutoff timing in the cylinder is controlled with the
component that is identified as the letter __________. Illustration MO-0097 |
I |
H |
C |
K |
|
D |
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 |
|
A |
Diesel engine
exhaust gas temperatures can be used to determine individual cylinder __________. |
performance |
horsepower output |
fuel consumption |
scavenge effect |
|
D |
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 |
|
A |
The instrument
shown in the illustration would be used on a diesel engine to __________.
Illustration MO-0031 |
measure cylinder
compression or firing pressures |
balance exhaust
gas temperature readings |
measure exhaust
gas pressure |
measure concentration
of chromate in jacket water |
|
D |
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 |
|
A |
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 |
|
A |
The diesel engine
shown in the illustration can be fitted with a pyrometer at each exhaust
elbow. If one of the cylinder pyrometers is reading significantly higher
than the others, which of the following should be your FIRST action? Illustration
MO-0005 |
Check the pump
rack setting. |
Examine the water
outlet header for evidence of blockage. |
Replace the fuel
injector nozzle. |
Examine the exhaust
valves for evidence of burning. |
|
B |
White smoke issuing
from the exhaust of an auxiliary diesel engine could mean __________. |
the engine is
overloaded |
the engine is
cold |
there is too much
lube oil in the cylinders |
the turbocharger
is fouled |
|
A |
A diesel engine
experiences a sudden loss in speed, accompanied by black exhaust smoke,
with the fuel rack at maximum, and the speed remaining below normal. The
probable cause is __________. |
engine overload |
leaky valves |
stuck or broken
piston rings |
low air injection
pressure |
|
A |
Heavy fuel oils
generally have an upper average ash content of 0.1% by weight. Which of
the following conditions could be expected if the ash content increases
above this amount? |
Increased exhaust
valve wear |
Increased MEP |
Excessive bearing
wear |
Glazing of the
cylinder liners |
|
B |
When running a
large, dual fuel, main propulsion diesel engine on heavy fuel, which of
the following precautions should be observed when switching from heavy fuel
oil to diesel oil? |
The diesel oil
must never be allowed to mix with the heavy fuel. |
The temperature
of the fuel from the preheater should be gradually reduced after switching
over the three-way valve. |
The heating steam
to the preheater should be increased as soon as the diesel fuel passes through
the three-way valve. |
The heating steam
must be secured before the diesel oil passes through the three-way valve. |
|
D |
When restarting
a heavy fuel diesel engine that has been stopped for some time, the engineer
should __________. |
increase the starting
air pressure |
use a higher than
normal cranking speed |
increase the fuel
injection pressure |
use a fuel having
a lower ignition temperature |
|
D |
One cause of diesel
engine fuel ignition delay is __________. |
mechanical flexibility
in the pump mechanism |
low fuel booster
pump pressure |
high fuel rack
setting |
ignition quality
of the fuel oil |
|
A |
When a fuel injection
nozzle overheats, which of the problems listed can be expected? |
The fuel metering
will vary. |
The fuel will
explode. |
The cylinder head
will crack. |
The engine will
stop. |
|
D |
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 |
|
A |
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 |
|
B |
Surface irregularities,
such as erosion and pitting on injection pump plungers, will __________. |
increase ignition
delay |
affect fuel oil
metering |
affect engine
performance at low speed only |
disappear due
to fuel oil abrasion |
|
A |
As shown in the
illustration, which of the following conditions would be responsible for
a "low pressure in oil outlet" alarm to be indicated? Illustration
MO-0127 |
Throughput too
low |
Separating temperature
too low |
Controller set
point changed |
Emergency stop
button not reset |
|
D |
While operating
the fuel oil centrifuge shown in the illustration, the bowl fails to open
for sludge ejection. The probable cause is that __________. Illustration
MO-0012 |
one or more of
the sludge ports is partially clogged |
the operating
water pressure is too high |
the bowl disk
set is clogged |
the seal ring
on the operating slide is defective |
|
A |
While operating
the fuel oil centrifuge shown in the illustration, the fuel oil is being
continuously ejected with the sludge and the seal water. The probable cause
is the __________. Illustration MO-0012 |
gravity disk inside
diameter is too large |
gravity disk inside
diameter is too small |
back pressure
is too low |
incorrect number
of disks have been place in the disk stack |
|
D |
Which of the following
statements describes what will occur if the annular spaces, indicated by
the letter "K" of the device shown in the illustration, became
restricted? Illustration MO0112 |
The bowl will
fail to close, but the unit will be capable of shooting while in operation. |
Operating water
will be supplied through port "S". |
The unit will
not start due to pressure/time delay relays. |
The bowl will
fail to close when starting and the unit will not shoot when operating. |
|
C |
For a diesel engine,
approximately how long can an electric starter motor be operated continuously
before damage may begin to occur due to overheating? |
Overheating the
motor cannot occur. |
Not more than
90 seconds |
Not more than
30 seconds |
Not more than
60 seconds |
|
A |
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 |
|
B |
Which of the following
conditions is most likely to occur if the electric starter motor pinion
gear fails to disengage from the flywheel of a diesel engine after the engine
has started? |
Engine will stop |
Starting motor
will dangerously over speed |
Flywheel will
be damaged |
Combustion gases
will enter the air starting system |
|
C |
When starting
air is admitted, a diesel engine turns over very slowly without firing.
The cause may be __________. |
an obstruction
in an engine cylinder |
water accumulation
in some engine cylinders |
low starting air
pressure |
low scavenge air
pressure |
|
B |
When an additional
load is applied to a diesel engine which is using an inadequately inflated
air bladder clutch unit, you can expect __________. |
pneumatic seizure |
overheating because
of slipping shoes |
chipped reduction
gear teeth |
excessive wear
on the thrust bearings |
|
B |
Misalignment of
the drive shaft and propeller shaft flanges can be detected by using a dial
indicator or __________. |
inside micrometer |
feeler gage |
adjustable trammel |
sighting device |
|
B |
The gear drive,
shown in the illustration, can have the backlash determined best by using
a __________. Illustration MO-0091 |
lead wire |
feeler gauge |
lash indicator |
red dye indicator |
|
D |
The thrust bearing
shown in the illustration has over eight years of ahead running time. Measurements
show "i1" is 4 mm and "i2" is 1mm. Which of the following
conditions is indicated and what steps should be taken, if any? Illustration
MO-0121 |
A wear rate of
1.6 mm per year occurred. Although not excessive, this condition may require
more frequent monitoring. |
The stops in which
the thrust bearing block rides are worn, and it is necessary to return these
to their original specifications. |
A wear rate of
1.6 mm per year is excessive and requires immediate assistance from the
manufacturer's field support. |
No appreciable
wear has occurred, and the proper maintenance procedures should continue
to be followed. |
|
A |
What could cause
the bypass valve in a full-flow lubrication system to open? |
Clogged filter
element |
Bypass valve setting
is too high |
Check valve stuck
open |
Fuel dilution
of the lubricant |
|
C |
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 |
|
A |
Which of the following
effects will excessively cold lube oil have on the operation of a diesel
engine? |
The engine will
crank slowly and may fail to start. |
The engine will
over speed when started. |
The fuel oil supply
will become diluted resulting in rough running. |
The cooling system
will overheat causing the engine to stall. |
|
D |
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 |
|
D |
Clogged or partially
obstructed exhaust ports on a diesel engine can cause __________. |
over speeding
of the engine |
failure of the
engine to shut down |
no effect of engine
performance |
high exhaust temperatures |
|
A |
A diesel engine
may be hard to start if the __________. |
air intake is
restricted |
engine is cranked
too fast |
vibration dampener
is faulty |
exhaust back pressure
is low |
|
B |
Combustion gas
venting through the expansion tank can be caused by a __________. |
leaking oil cooler |
cracked cylinder
head |
worn piston ring |
leaking exhaust
valve |
|
D |
Some diesel engines
are fitted with a thermometer in the cooling water outlet from each cylinder.
If the cooling water temperature from all cylinders begins to rise above
normal, you should suspect __________. |
insufficient fuel
delivery to all cylinders |
increased blow-by
in all cylinders |
incomplete combustion
in all cylinders |
overloading in
all cylinders |
|
D |
A diesel engine
cylinder head can crack as a result of __________. |
a leaking oil
control ring |
heat transfer
from exhaust valves |
overheated intake
valves |
restricted cooling
passages |
|
C |
Antifreeze solutions
containing ethylene glycol should not be mixed with corrosion protection
oils, as the resultant mixture __________. |
is dangerously
flammable |
has a higher chloride
content |
may cause frothing |
promotes scale
buildup |
|
B |
Oil accumulating
in the exhaust piping or manifold of a diesel engine can be caused by __________. |
collapsed hydraulic
valve lifters |
worn valve guides |
excessive crankcase
vacuum |
excessive lube
oil pressure |
|
B |
If there is a
'clicking' sound in the valve compartment of a diesel engine, the cause
may be __________. |
a worn wrist pin |
excessive valve
lash |
worn connecting
rod bearings |
All of the above. |
|
B |
Excessive wear
at part #11, as shown in the illustration, would result in __________. Illustration
MO-0027 |
improper timing |
increased oil
consumption |
lost compression |
low oil pressure |
|
D |
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 |
|
B |
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 |
|
A |
High exhaust temperature
and black smoke exhausting from an auxiliary diesel engine can be caused
by __________. |
engine overload |
low combustion
temperature |
plugged fuel nozzle
holes |
excessive compression
pressure |
|
A |
Crank web deflection
readings will give a positive indication of __________. |
worn main bearing
journals |
crankpin misalignment |
slack thrust bearings |
bearing shells
shim dimensions |
|
B |
Prior to starting,
the purpose of turning over a main propulsion diesel engine with the cylinder
test cocks open, is to __________. |
test the starting
system |
remove condensation
and other liquids from the cylinders |
check the compression |
check for proper
lube oil pressure |
|
A |
The thrust bearing
shown in the illustration has over eight years of ahead running time. Measurements
show "i1" is 4 mm and "i2" is 1mm. Which of the following
conditions is indicated and what steps should be taken, if any? Illustration
MO-0121 |
No appreciable
wear has occurred, and the proper maintenance procedures should continue
to be followed. |
A wear rate of
1.6 mm per year occurred. Although not excessive, this condition may require
more frequent monitoring. |
The stops in which
the thrust bearing block rides are worn, and it is necessary to return these
to their original specifications. |
A wear rate of
1.6 mm per year is excessive and requires immediate assistance from the
manufacturer's field support. |
|
B |
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. |
|
D |
Excessive vibration
from an auxiliary boiler could be caused by __________. |
combustion pulses |
insufficient air
to the burner |
loose hold-down
bolts |
All of the above. |
|
C |
High stack temperature
occurring in an auxiliary boiler could be a result of __________. |
insufficient air
for combustion |
complete combustion
in the furnace |
secondary combustion
in the uptake |
high fuel oil
temperature |
|
D |
Which of the following
conditions could cause the feed pump for an auxiliary boiler to lose suction? |
Increased suction
head pressure |
Decreased feed
water temperature |
Pump recirculating
line being open too much |
Excessive feed
water temperature |
|
A |
If the wearing
rings of device "7" shown in the illustration become worn, how
will the evaporation rate in "23" be affected? Illustration MO-0111 |
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. |
|
D |
If valve "D"
is opened during the normal operation of the distiller shown in the illustration,
which of the events listed will occur? Illustration MO-0111 |
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. |
|
A |
What would be
the first indication that a tube leak has occurred in area "23"?
Illustration MO-0111 |
The level in area "1"
would decrease. |
The level in area "1"
would increase. |
The level in area "3"
would increase. |
The level in area "3"
would decrease. |
|
D |
Which of the conditions
listed would indicate a large condenser tube leak within the distiller shown
in the illustration? Illustration MO-0111 |
A decrease in
the level of the main engine expansion tank as indicated by a low level
alarm. |
An increase in
distiller output resulting from the combination of jacket water and the
distillate produced. |
A slow continuous
rise in the lube oil cooler outlet temperature indicated at device "4". |
The activation
of the salinity monitoring equipment's annunciator circuit. |
|
D |
If the operating
speed of a diesel engine increases without an apparent change in the engine
control settings, you may suspect a __________. |
clogged intake
air intercooler |
control air leak |
leaking air starting
valve |
malfunctioning
governor |
|
D |
Governor hunting
is caused by __________. |
governor under-control |
excessive speed
droop |
insufficient speed
droop |
governor over-control |
|
D |
The hunting of
a diesel engine may be caused by __________. |
excessive speed
droop |
insufficient speed
droop |
excessive sensitivity |
low governor power |
|
C |
If the speeder
spring of a main propulsion diesel engine governor breaks while operating
at full load, the engine RPM will __________. |
increase until
the over speed trip actuated |
hunt until stabilized
by the droop rod |
decrease to a
slightly lower value |
remain the same
until manually changed |
|
C |
A diesel engine
operates erratically, over speeds, and fails to restart when cranked at
normal speed. Which of the following problems is the most likely cause for
the engine failing to restart? |
Improper governor
operation due to excess oil pressure |
Damage to the
governor due to excessive speed |
Failure to reset
the over speed trip |
Failure to reposition
the fuel rack |
|
A |
A propulsion engine,
using the speed control circuit shown in the illustration, fails to function
at speeds lower than the low end of the critical speed range. Which of the
following statements describes what should be done to correct this malfunction?
Illustration MO-0114 |
Device 17A needs
to be replaced, repaired, or reset to the set point coinciding with the
RPM value for the low end of the critical speed range. |
The critical speed
range will be varied as the set points of 17A or 17B are reset, therefore,
another segment of the speed control circuit must be repaired. |
To increase the
critical speed range of the engine, reduce the set point of 17A and 17B
respectively, to .80 bar and 1.0 bar. |
Both 17A and 17B
need to be reset to decrease the critical speed range, although this procedure
will increase the operating range of the engine. |
|
C |
The governor utilized
with the device shown in the illustration has become inoperative while the
vessel is underway at sea. Which of the following statements describes what
action should be taken? Illustration MO-0119 |
It is necessary
to disconnect the shuttle valve from the throttle lever horizontal bar,
in order to effectively jump out the pneumatic engine enable control circuit. |
The governor should
be replaced with one that has been proven to be useful in isochronous applications. |
The engine speed
can be controlled using the fuel control lever without changing the position
of the maximum fuel stop. |
The linkage to
the shut down servomotor and the governor output shaft must be disconnected
in order to operate the engine via the fuel control lever. |
|
C |
The power output
of a turbo-charged diesel engine will drop if the cooling water flow through
the after cooler is interrupted because the __________. |
turbocharger stalls |
exhaust pressure
increases |
air charge density
decreases |
scavenge effect
increases |
|
D |
Corrosion and
grooving on the blading of an exhaust driven turbocharger is caused by certain
components of residual fuel oils. These components are vanadium, sodium,
and __________. |
copper |
carbon |
hydrogen |
sulfur |
|
D |
Excessive mechanical
and pulsating vibrations developed in a main propulsion diesel engine may
be more likely to cause damage to an attached __________. |
scavenged air
pump because it is designed for steady state operation rather than pulsating
gas load |
reciprocating
scavenge pump because of its direct linkage to the crankshaft |
centrifugal cooling
water pump because of the close tolerances required between the impeller
rim and the volute |
gas driven turbocharger
because it has a wide speed range, high operating temperatures and close
tolerances. |
|
A |
Differential needle
valves used in fuel injectors are directly closed by __________. |
spring force |
firing pressure |
cam action |
fuel oil pressure |
|
B |
Carbon deposit
build up on the injection nozzle orifice is least likely to occur when using
which type of fuel injector nozzle? |
Hole |
Pintle |
Multi-pintle |
Multi-hole |
|
B |
The item labeled
#16 in the illustration is a stack of spring washers. Their function is
to __________. Illustration MO-0062 |
permit accurate
stretch gauge measurement of bolt elongation during installation |
maintain the same
hold-down force on the injector regardless of varying engine operating temperatures |
prevent bolt failure
by allowing limited movement of the injector when excessively high cylinder
pressures are developed |
absorb the high
pressure pulses developed during the fuel injection process |
|
A |
Regarding the
fuel injector shown in the illustration, the purpose of piece #38 is to
__________. Illustration MO-0059 |
filter the fuel |
adjust the fuel
rack spring tension |
maintain fuel
pressure at a preset level |
relieve excess
fuel pressure to the suction side of the pump |
|
D |
Which type of
diesel engine fuel nozzle is shown in the illustration? Illustration MO-0059 |
Open |
Pintle |
Self-cleaning |
Multi-hole |
|
D |
The amount of
fuel delivered by a unit injector is controlled by the __________. |
engine speed |
main spring |
camshaft |
rack position |
|
B |
The indicated
position of the fuel injection pump plunger as shown in the illustration
will provide fuel delivery to the diesel engine in an amount approximately
equal to __________. Illustration MO-0061 |
normal fuel flow |
maximum fuel flow |
zero fuel flow |
light fuel flow |
|
D |
Which of the following
statements represents the function of the plunger flange labeled "A"
shown in the illustration? Illustration MO-0061 |
It prevents the
plunger from rotating in the barrel. |
It limits the
actual stroke of the plunger. |
It takes the plunger
off stroke when injection is completed. |
It transmits the
control rack setting to the plunger. |
|
A |
As shown in the
illustration of the fuel injection pump, the section designated as "M"
is referred to as the __________. Illustration MO-0061 |
plunger helix |
plunger relief
shoulder |
plunger control
tab |
plunger sleeve |
|
A |
As shown in the
illustration of the fuel injection pump, the component labeled "N"
would be identified as the __________. Illustration MO-0061 |
Barrel |
Sleeve |
Control Rack |
Plunger |
|
C |
As shown in the
illustration of the fuel injection pump, the function of the area designated
as "L" is to __________. Illustration MO-0061 |
relieve excessive
injector discharge pressure |
control the fuel
injection rate |
allow excess fuel
oil to return to the fuel oil system |
provide for plunger
lubrication |
|
A |
In the illustration
shown, moving the component labeled "E", further to the left,
will result in __________. Illustration MO-0061 |
a shorter fuel
injection cycle |
a greater quantity
of fuel injected |
an increase in
the cylinder mean effective pressure |
an increase in
fuel pump delivery pressure |
|
D |
What is the purpose
of the "window" installed in the housing of an individual jerk
pump? |
To set up the
fuel rack calibration in cubic millimeters. |
To check that
fuel oil return passages are clear. |
To check for sludge
on the pump barrel. |
To allow the pump
to be timed to the engine. |
|
A |
Injection pressure
in a common rail fuel system is controlled by __________. |
a bypass valve |
varying the injector
needle valve clearance |
engine speed |
varying the fuel
pump piston stroke |
|
C |
The component
shown in the illustration would be identified as a __________. Illustration
MO-0097 |
slow speed engine
cylinder liner lubricator |
centrifugal flyweight
governor |
slow speed engine
fuel pump |
injector cooling
system pump |
|
C |
The component
shown in the illustration would be identified as a __________. Illustration
MO-0097 |
slow speed engine
cylinder liner lubricator |
centrifugal flyweight
governor |
slow speed engine
fuel pump |
injector cooling
system pump |
|
C |
The component
identified as item #15 is used to __________. Illustration MO-0016 |
test injector
popping pressure |
advance fuel pump
timing |
stop fuel delivery
to the injector |
increase the fuel
pump delivery pressure |
|
A |
In the large slow-speed
main propulsion diesel engine shown in the illustration, the part labeled "G"
is the __________. Illustration MO-0003 |
fuel oil pump |
jacket water pump |
lube oil pump |
crankcase exhaust
fan |
|
A |
According to the
illustration, initial timing of fuel injection into the cylinder is controlled
with the component that is identified as the letter __________. Illustration
MO-0097 |
C |
H |
I |
K |
|
D |
According to the
illustration, fuel cutoff timing in the cylinder is controlled with the
component that is identified as the letter __________. Illustration MO-0097 |
H |
K |
C |
I |
|
D |
When disassembling
or assembling an injection pump plunger and barrel you should __________. |
work over a linoleum-type
surface |
always keep the
plunger and barrel as a matched set |
keep the parts
immersed in diesel fuel |
All of the above. |
|
A |
You are testing
a closed fuel injection nozzle using a nozzle tester. A pressure slightly
less than design valve opening pressure is applied. If no fuel appears at
the spray tip, the __________. |
needle valve is
operating properly |
nozzle orifices
are too small |
needle valve spring
is defective |
nozzle orifices
are eroded |
|
A |
Because of the
close tolerances used in diesel engine fuel oil pumps, a worn plunger requires
__________. |
replacing the
plunger and the barrel |
highly polishing
both the plunger and barrel |
grinding the spare
plunger to the barrel |
replacing plunger
only |
|
C |
Uneven bolt tightening
during the installation of a fuel injection pump can result in __________. |
high torsional
shock to fuel lines |
ignition delay |
binding of pump
moving parts |
improper pump-to-engine
timing |
|
C |
Which of the fuel
nozzles listed requires the LEAST maintenance? |
Open |
Single hole |
Pintle |
Multi-hole |
|
A |
Which of the following
statements concerning the factors affecting ignition delay is correct? |
An increase in
coolant temperature will decrease ignition delay. |
An increase in
intake air temperature will increase ignition delay. |
An increase in
compression ratio will increase ignition delay. |
An increase in
combustion chamber turbulence will increase ignition delay. |
|
B |
One cause of diesel
engine surging can be a result of __________. |
low compression |
injection pump
fuel rack binding or sticking |
solenoid stuck
open |
fuel booster pump
pressure too high |
|
A |
Heat damage to
fuel injection nozzles can be prevented by avoiding __________. |
long periods of
engine overload |
metallic contact
between nozzles and cylinder heads |
hard carbon deposit
and varnish on the nozzles |
excessive fuel
oil temperature |
|
B |
One cause of diesel
engine surging can be a result of __________. |
low compression |
injection pump
fuel rack binding or sticking |
solenoid stuck
open |
fuel booster pump
pressure too high |
|
C |
In the common
rail system, excessive pressure in the header may be caused by __________. |
a malfunctioning
injection nozzle |
insufficient leakoff
through injection nozzle packing |
improper adjustment
of the bypass valve |
a dribble in the
fuel injection nozzle |
|
B |
High firing pressures
and a low exhaust temperature in a diesel engine may result from __________. |
increased exhaust
system back pressure |
early fuel injection
timing |
early exhaust
valve opening |
low scavenge air
temperature |
|
A |
Surface irregularities,
such as erosion and pitting on injection pump plungers, will __________. |
affect fuel oil
metering |
affect engine
performance at low-speed only |
disappear due
to fuel oil abrasion |
increase ignition
delay |
|
C |
While examining
a used fuel injection nozzle(s), one finds worn and enlarged orifices. What
does this indicate about that cylinder's performance prior to nozzle replacement(s)? |
Volume of atomization
is increased, penetration is reduced, vaporization is increased, efficiency
is not effected. |
Volume of fuel
injected is increased, reduced injection pressure, decreased ignition delay. |
Reduced combustion
efficiency, increased ignition delay, reduced atomization, prolonged penetration. |
Penetration is
increased, air/fuel mixture is increased, cylinder efficiency is not substantially
effected. |
|
A |
Injection lag
in a diesel engine may be caused by __________. |
the flexibility
of high-pressure fuel lines |
a decrease in
the air temperature |
a decrease in
compression pressure |
a change in the
cetane number of the fuel |
|
C |
Poor combustion
in a diesel engine can be caused by __________. |
high scavenge
air pressure |
low exhaust pressure |
low compression
temperature |
high compression
pressure |
|
C |
Diesel fuel oil
having a low cetane rating can result in __________. |
smoother engine
operation |
reduce ignition
lag |
combustion knock |
improved cold
weather starting |
|
B |
Faulty operation
of diesel engine fuel injection nozzles can be a direct cause of __________. |
excessive fuel
nozzle holder cooling |
sediment in the
fuel supply |
improper atomization
of the fuel |
distortion of
the fuel spray pattern |
|
C |
Which of the following
problems is the main source of fuel pump and injection system malfunctions? |
Coated fuel lines |
Improper lubrication |
Air in the fuel
system |
Excessive vibration |
|
D |
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 |
|
D |
Problems with
the diesel engine fuel injection pump are usually caused by __________. |
kinked fuel lines |
excessive engine
vibration |
improper adjustment |
contaminated fuel |
|
C |
When is fuel injected
into a cylinder of diesel engines? |
After combustion
gases in the cylinder have expanded. |
As air is taken
into the cylinder. |
After air in the
cylinder is compressed. |
Before air in
the cylinder is compressed. |
|
A |
The time between
injection and ignition of the fuel is known as __________. |
ignition delay |
after burning
ratio |
injection lag |
turbulence lag |
|
B |
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
ignition lag will increase the compression ratio. |
A decrease in
compression ratio will decrease the ignition lag. |
|
B |
The rate of pressure
rise during the period following fuel ignition in a diesel engine is influenced
by the length of the ignition delay period and the __________. |
volumetric efficiency |
turbulence of
the air charge |
fuel efficiency |
valve overlap |
|
D |
The pressure in
an operating diesel engine cylinder continues to rise for a short period
after the piston passes top dead center as a result of the __________. |
fuel injection
occurring at that point and combustion begins |
exhaust and intake
valves just closing |
maximum compression
pressure is just being attained |
expansion during
the combustion process |
|
D |
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 |
be completed exactly
at top dead center |
end at bottom
dead center |
continue through
the after-burning period |
|
D |
Which statement
about diesel engine combustion is true? |
Maximum combustion
pressure is reached before TDC. |
Combustion does
not begin until the piston starts down on the power stroke. |
Turbulence in
the cylinder causes a delay in ignition. |
Maximum cylinder
firing pressure is not developed until the piston passes TDC. |
|
D |
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 |
be completed exactly at top
dead center |
end at bottom
dead center |
continue through
the afterburning period |
|
C |
Catalytic fines
comprised of aluminum oxide and/or silicon dioxide are a common contaminant
of residual fuels. Which diesel engine components would be most effected
by catalytic fines in fuel? |
High pressure
fuel pumps and cylinder liners. |
Fuel injectors
and piston rings. |
High pressure
fuel pumps and fuel injectors. |
Fuel injectors
and turbocharger blading. |
|
C |
Does sulfur content
of heavy fuel oil effect the fuel rate of a diesel engine and why or why
not? |
No, it only effects
possible acid corrosion of engine components. |
Yes, it may increase
wear of engine components and thus piston ring blow-by. |
Yes, high sulfur
content decreases calorific value of fuel. |
No, it does not
effect efficiency of combustion. |
|
C |
As Chief Engineer
of a slow speed diesel propelled vessel operating with constant slip, when
considering the effect on the fuel consumption in barrels per mile of a
planned increase in operating RPM you utilize which of the following? |
fuel consumption
varies as the square of the shaft RPM |
fuel consumption
varies directly proportional to the shaft RPM |
fuel consumption
varies as the cube of the shaft RPM |
fuel consumption
varies inversely with the shaft RPM |
|
B |
You are on board
a vessel with a slow speed crosshead type engine. The fuel just received
has a significantly lower sulfur content then the previous bunkers. Which
of the following would be a concern due to the reduced sulfur content? |
Fuel injection
temperature |
Base number of
the cylinder oil |
Fuel supply system
pressure |
Purifier gravity
disk size |
|
A |
Heavy fuel oils
generally have an upper average ash content of 0.1% by weight. Which of
the following conditions could be expected if the ash content increases
above this amount? |
Increased exhaust
valve wear |
Increased MEP |
Excessive bearing
wear |
Glazing of the
cylinder liners |
|
B |
While bunkering
heavy fuel, what quick/easy test can one perform onboard to determine the
compatibility of 'old' with 'new' fuel? |
Take equal samples
of both fuels, elevate their temperature, mix them vigorously. If no frothing
occurs, they are compatible. |
Use blotter paper
with a single concentric drop of 'old' and 'new' fuel, if they do not form
separate circles, the fuels may be deemed compatible. |
Mix two equal
samples of the two fuels at elevated temperatures and determine if they
become a homogeneous mixture. |
Perform a running
viscosity test of both fuels, at the same temperature, if the viscosities
are equal, they should be compatible. |
|
D |
The purpose of
the interlocked three-way valve shown in the illustration is to __________.
Illustration MO-0058
|
recirculate fuel
through the heater during warm-up |
control the rate
of fuel oil flow to the engines |
act as an emergency
fuel shut off, regardless of the fuel being used |
change fuel from
heavy to light oil or vice-versa while insuring that oil is returned to
the proper day tank |
|
A |
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 |
|
A |
Which of the listed
substances can be satisfactorily removed from diesel fuel by centrifuging? |
Sludge |
Gasoline |
Fuel oil |
Lube oil |
|
C |
Which factor determines
the size of the ring dam for a fuel oil centrifugal purifier? |
The viscosity
of the fuel. |
The quantity of
water to be removed from the fuel. |
The specific gravity
of the fuel. |
The quantity of
dirt to be removed from the fuel. |
|
B |
Whether using
a centrifuge or a simple filter, oil cleaning and filtration will be the
most effective when the oil is at a __________. |
high temperature
and a high viscosity |
high temperature
and a low viscosity |
low temperature
and a high viscosity |
low temperature
and a low viscosity |
|
B |
The temperature
of the contaminated fuel oil fed to the centrifuge shown in the illustration
should be __________. Illustration MO-0012 |
greater than 212°F |
203°F to less
than 212°F |
160°F to 180°F |
selected according
to the oil's viscosity index |
|
B |
All alarms occurring
on the control unit of the device shown in the illustration will __________.
Illustration MO-0127 |
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 |
|
A |
How may water
be removed from the bowl of the separator as shown in the illustration?
Illustration MO-0127 |
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. |
|
A |
Which of the following
statements represents the working principle of the water transducer used
with the separator shown in the illustration? Illustration MO-0127 |
The probe and
sensor measure the dielectric constant through capacitive reactance of the
process fluid.
|
As the water content
in the oil decreases, the dielectric constant increases.
|
The capacitor
completes part of the inductive circuit which monitors pressure changes.
|
All of the above. |
|
D |
The device shown
in the illustration can be automatically or manually desludged. The closing
sequence at the end of the desludging cycle is initiated by opening which
of the labeled components listed below? Illustration MO-0012 |
R |
P |
F |
Q |
|
A |
The greatest difference
between the centrifuge bowl shown in the illustration and that of a tubular
bowl, with straight, vertical, interior surfaces, is that the illustrated
unit __________. Illustration MO-0012 |
is self desludging
|
rotates at 1000
rpm higher than the old tubular bowl type
|
rotates at 1000
rpm slower than the old tubular bowl type
|
does not require
a discharge ring when operated as a separator |
|
A |
Which of the labeled
figures illustrated, represents the correct alignment mark relationships
of a properly reassembled centrifuge bowl? Illustration MO-0022 |
A |
B |
C |
D |
|
D |
Which of the following
precautions should be taken prior to starting the separator shown in the
illustration? Illustration MO-0127
|
Make sure the
separator is properly assembled.
|
Check for the
correct oil level in the gear housing. |
Release the bowl
brake and confirm proper valve line up. |
All of the above. |
|
C |
How is oil supplied
to the device shown in the illustration? Illustration MO-0127 |
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. |
|
C |
Which of the following
statements is accurate concerning the vibration sensing device used with
the separator shown in the illustration? Illustration MO-0127 |
Vibration sensors
are not used with centrifuges currently installed on diesel vessels due
to excessive vibrations developed by the main propulsion units.
o |
The vibration
switch is sensitive to vibration in a direction horizontal to its mounting
base and is normally installed low on the separator where movement is magnified. |
The detector mechanism
consists of an armature suspended on a flexure pivot and restrained from
motion by a permanent magnet acting through a small air gap.
o |
The detector is
so arranged to prevent abnormal harmonic frequencies from being developed
while the separator is passing through its critical speed range. |
|
B |
The system shown
in the illustration utilizes a water transducer which is __________. Illustration
MO-0127 |
a mechanical/electrical
device with a variable dc output |
located in the
oil outlet piping
|
similar to those
used in sonar systems
|
essential in monitoring
the amount of water entering the separator |
|
D |
In the device
shown in the illustration, the component lettered "A" is the __________.
Illustration MO-0012 |
seal water input
port
|
heavy phase discharge
port |
light phase discharge
port |
dirty oil input
port |
|
C |
The device labeled "A",
shown in the illustration, is known as the __________. Illustration MO-0112 |
centripetal pump
cover |
bowl assembly
hood |
regulating ring |
kinetic converter |
|
B |
Which of the following
statements describes "N" shown in the illustration? Illustration
MO-0112 |
the included angle
of oil flow |
the centrifuge
disc stack |
the sole direction
of heavy phase flow |
the relative size
of the separation zone |
|
C |
Item "O"
of the device shown in the illustration is the __________. Illustration
MO0112 |
fair flow nut |
inlet directional
guide |
spindle nut |
impeller locking
device |
|
D |
The wear liner
shown in the illustration is indicated by the letter __________. Illustration
MO-0112 |
"G" |
"N" |
"P" |
"R" |
|
C |
The discharge
nozzle shown in the illustration, is indicated by the letter __________.
Illustration MO-0112 |
A |
K |
S |
X |
|
D |
The gasket "U"
shown in the illustration, is used to seal the liquid space below the __________.
Illustration MO-0112 |
ring dam |
inner bowl |
outer bowl |
sliding piston |
|
D |
The port "X"
shown in the illustration allows water to enter the adjoining chamber. During
what cycle of operation will this occur? Illustration MO-0112 |
Operating back
flush cycle |
Bowl retention
cycle |
Clarification
cycle |
Sludge discharge
cycle |
|
D |
The area indicated
by the letter "W", shown in the illustration is correctly termed
the __________. Illustration MO-0112 |
closing chamber |
parting chamber |
upper sliding
piston chamber |
opening chamber |
|
D |
What is used as
the primary operating medium during the sludge discharge cycle, shown in
the illustration? Illustration MO-0112 |
Light phase liquid
o |
Heavy phase liquid |
Hydraulic fluid |
Water |
|
C |
Where does the
shoot cycle operating liquid first come in contact with the rotating forces
of the device shown in the illustration? Illustration MO-0112 |
While traveling
under disc stack "N". |
At the inlet cone
labeled "O". |
In the opening
chamber labeled "L".
|
At the inlet orifice
labeled "S". |
|
B |
The unit shown
in the illustration is beginning the sludge discharge cycle. The operating
liquid solenoid valve has been energized and space "J" is filling
up. Which of the following actions should occur next? Illustration MO-0112 |
The liquid enters
the opening space, controlled by the discharge port "S", thereby
causing the sliding bowl bottom to move upwards. |
The liquid enters
via port "X" into the opening space with the net resultant force
causing the piston slide to move down. |
The liquid enters
via port "X", travels through the closing chamber, and exits port "S",
maintaining an upward force against the bowl bottom, |
The liquid remains
trapped in space "J", developing an upward force to open the bowl. |
|
A |
The device labeled
'C' shown in the illustration is known as the __________. Illustration MO-0112 |
upper locking
ring
|
lower paring device
|
upper paring gasket
|
pump lock |
|
C |
What terminates
the sludge discharge cycle of the device shown in the illustration? Illustration
MO-0112 |
The solenoid valve
opens, directs high pressure fluid into the closing chamber, and results
in an upward movement of the sliding piston. |
The solenoid valve
closes, reduces the water pressure to the paring chamber, and allows the
spring force to move the sliding piston upward. |
The solenoid valve
closes, allows the water in the opening chamber to bleed off through "S",
and the sliding piston moves upward due to the force developed in area "J". |
The solenoid valve
closes, allows the weight of the sliding piston to oppose the low water
pressure, and moves it along the axis of the spindle. |
|
B |
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?
Illustration MO-0112 |
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. |
|
D |
The device labeled "B",
shown in the illustration, is known as the __________. Illustration MO-0112 |
upper ring chamber |
set of regulating
rings |
comminuting device |
centripetal pump
chamber cover |
|
B |
The device labeled "D",
as shown in the illustration, is the bowl __________. Illustration MO-0112 |
hood |
top |
cover |
hub |
|
D |
The item indicated
by the letter "F" of the device shown in the illustration is the
__________. Illustration MO-0112 |
guide band |
guide pin |
locating dowel
pin |
upper bowl gasket |
|
B |
The device labeled "H",
shown in the illustration is referred to as the __________. Illustration
MO-0112 |
upper chamber
bowl gasket |
centrifugation
chamber bottom gasket |
sliding piston
upper seal |
sliding piston
lower seal |
|
C |
The force developed
by the liquid within space "J" of the device shown in the illustration
depends upon __________. Illustration MO-0112 |
the speed of the
bowl and the condition of seal "H" |
the angular velocity
at which the liquid travels |
the speed of the
bowl and the condition of seal "U" |
inertia forces
during starting and stopping |
|
A |
During normal
operation, the liquid retained in space 'J' of the device shown in the illustration
is __________. Illustration MO-0112 |
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 |
|
D |
The area indicated
by the letter "L" of the device shown in the illustration is properly
called the __________. Illustration MO-0112 |
pre-injection
chamber |
operating water
reservoir |
channeling chamber |
injection chamber |
|
D |
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?
Illustration MO-0113 |
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. |
|
D |
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 68°F, and the separating temperature is 158°F __________.
Illustration MO-0113 |
117 mm |
104 mm |
86 mm |
110 mm |
|
C |
Using the graph
shown in the illustration, the oil being separated has a specific gravity
of .87 kg/dm3 at 72.5°C. What will be the specific gravity if the temperature
is lowered to 40°C? Illustration MO-0113 |
0.872 kg/dm3 |
0.882 kg/dm3 |
0.892 kg/dm3 |
0.902 kg/dm3 |
|
C |
From the graph
shown in the illustration, if the separating temperature required is to
be 167°F, and the specific gravity of the oil is .98 kg/dm3 at 59°F, what
size regulating ring is required? Illustration MO-0113 |
86 mm |
89 mm |
92 mm |
95 mm |
|
D |
The replacement
piping for diesel engine high pressure fuel systems must be the same length
and diameter as the original piping to __________. |
avoid unnecessary
parts inventory |
keep torsional
vibration constant |
use existing supports
and braces |
maintain specified
injection characteristics |
|
D |
Which of the listed
types of gasket material should be used on high pressure fuel oil lines
on a diesel engine? |
Fiberglass |
Sheet asbestos |
Neoprene |
Soft copper |
|
A |
The diesel engine
shown in the illustration has the highest fuel pressure developed in the
part labeled __________. Illustration MO-0003 |
E |
X |
Y |
Z
|
|
D |
To minimize corrosion,
fuel oil strainer disks, spacers and scraper blades are made of __________. |
brass |
copper |
iron |
monel metal or
stainless steel |
|
D |
The purpose of
the interlocked three-way valve shown in the illustration is to __________.
Illustration MO-0058
|
recirculate fuel
through the heater during warm-up |
control the rate
of fuel oil flow to the engines |
act as an emergency
fuel shut off, regardless of the fuel being used |
change fuel from
heavy to light oil or vice-versa while insuring that oil is returned to
the proper day tank |
|
A |
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 |
|
B |
As shown in the
illustration, the viscosimeter would be used to directly control the output
of which of the following components? Illustration MO-0077 |
Outflow from HFO
day tank. |
Final heaters. |
Injector pumps. |
HFO purifiers. |
|
C |
Heavy fuel oil
used in the system shown in the illustration, will have the lowest viscosity
__________. Illustration MO-0058 |
in the settling
tank |
at the transfer
pump discharge |
at the main engine
fuel oil header |
in the three-way
valve
|
|
C |
In pre-treating
fuel oil on a motor vessel, what would you consider the most important factor
to prevent high temperature corrosion on an engine's combustion components? |
Recycle the fuel
between the settling tank(s) and service tank via centrifuges more than
once. |
Monitor engine(s)
exhaust temperatures more closely. |
Run one centrifuge
as a purifier at a reduced rate to minimize water, especially salt water,
in
the fuel. |
Drain settling
tank(s) and service tank more often only. |
|
A |
The temperature
of the contaminated fuel oil fed to the centrifuge shown in the illustration
should be __________. Illustration MO-0012 |
203°F to less
than 212°F |
greater than 212°F |
160°F to 180°F |
selected according
to the oil's viscosity index |
|
D |
The greatest difference
between the centrifuge bowl shown in the illustration and that of a tubular
bowl, with straight, vertical, interior surfaces, is that the illustrated
unit __________. Illustration MO-0012 |
does not require
a discharge ring when operated as a separator |
rotates at 1000
rpm slower than the old tubular bowl type |
rotates at 1000
rpm higher than the old tubular bowl type |
is self desludging |
|
A |
In the device
shown in the illustration, the component lettered "A" is the __________.
Illustration MO-0012 |
dirty oil input
port |
heavy phase discharge
port |
seal water input
port |
light phase discharge
port |
|
A |
The device labeled "D",
as shown in the illustration, is the bowl __________. Illustration MO-0112 |
top |
hood |
hub |
cover |
|
C |
The area indicated
by the letter "W", shown in the illustration is correctly termed
the __________. Illustration MO-0112 |
upper sliding
piston chamber |
closing chamber |
opening chamber |
parting chamber |
|
D |
What terminates
the sludge discharge cycle of the device shown in the illustration? Illustration
MO-0112 |
The solenoid valve
opens, directs high pressure fluid into the closing chamber, and results
in an upward movement of the sliding piston. |
The solenoid valve
closes, reduces the water pressure to the paring chamber, and allows the
spring force to move the sliding piston upward. |
The solenoid valve
closes, allows the weight of the sliding piston to oppose the low water
pressure, and moves it along the axis of the spindle. |
The solenoid valve
closes, allows the water in the opening chamber to bleed off through "S",
and the sliding piston moves upward due to the force developed in area "J". |
|
D |
Which of the following
precautions should be taken prior to starting the separator shown in the
illustration? Illustration MO-0127 |
Check for the
correct oil level in the gear housing. |
Make sure the
separator is properly assembled. |
Release the bowl
brake and confirm proper valve line up. |
All of the above. |
|
D |
Which of the following
statements is accurate concerning the vibration sensing device used with
the separator shown in the illustration? Illustration MO-0127 |
The vibration
switch is sensitive to vibration in a direction horizontal to its mounting
base and is normally installed low on the separator where movement is magnified. |
Vibration sensors
are not used with centrifuges currently installed on diesel vessels due
to excessive vibrations developed by the main propulsion units. |
The detector is
so arranged to prevent abnormal harmonic frequencies from being developed
while the separator is passing through its critical speed range. |
The detector mechanism
consists of an armature suspended on a flexure pivot and restrained from
motion by a permanent magnet acting through a small air gap. |
|
C |
How may water
be removed from the bowl of the separator as shown in the illustration?
Illustration MO-0127 |
The separator
is used to remove solids from the processed liquid, therefore the accumulation
of water does not present a problem. |
Water may only
be removed from the bowl when the unit is secured and the bowl hood is removed. |
The water may
be removed through the water drain valve or through the sludge ports during
the sludge discharge cycle. |
When the unit
is secured and the bowl stops rotating, the water is drained off the bottom
of the bowl through orifice ports. |
|
D |
Heavy fuel oil
used in the system shown in the illustration, will have the lowest viscosity
__________. Illustration MO-0058 |
at the transfer
pump discharge |
in the settling
tank |
in the three-way
valve |
at the main engine
fuel oil header |
|
B |
The purpose of
the interlocked three-way valve shown in the illustration is to __________.
Illustration MO-0058
|
control the rate
of fuel oil flow to the engines |
change fuel from
heavy to light oil or vice-versa while insuring that oil is returned to
the proper day tank |
act as an emergency
fuel shut off, regardless of the fuel being used |
recirculate fuel
through the heater during warm-up |
|
B |
When changing
over from residual to distillate fuel on a slow-speed diesel main engine,
what is a good guideline to follow regarding the change over? |
Change over time
should not be less than six hours. |
Rate of temperature
change of fuel to the engine should not exceed 2 degrees C per minute. |
Change over should
be accomplished as quickly as possible as dictated by engine load. |
Change over time
should not exceed two hours. |
|
A |
When changing
over from residual to distillate fuel on a slow-speed diesel propelled vessel,
you should limit the rate of temperature change of the fuel in order to
prevent what operational difficulty? |
Seizing and scuffing
of fuel pump plungers and injector needle valves due to thermal effects
on close clearance components. |
Dezincafication
of the fuel in the mixing tank. |
Surging/hunting
of the governor due to rack sticking. |
Carbonization
in the fuel heater. |
|
B |
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?
Illustration MO-0113 |
For a constant
operating temperature, the greater the specific gravity of the oil the larger
the
regulating ring. |
The larger sized
regulating rings are designed to be used with oils of lower specific gravities. |
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. |
|
D |
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 68°F, and the separating temperature is 158°F __________.
Illustration MO-0113 |
86 mm |
117 mm |
104 mm |
110 mm |
|
B |
Using the graph
shown in the illustration, the oil being separated has a specific gravity
of .87 kg/dm3 at 72.5°C. What will be the specific gravity if the temperature
is lowered to 40°C? Illustration MO-0113 |
0.902 kg/dm3 |
0.892 kg/dm3 |
0.882 kg/dm3 |
0.872 kg/dm3 |
|
B |
From the graph
shown in the illustration, if the separating temperature required is to
be 167°F, and the specific gravity of the oil is .98 kg/dm3 at 59°F, what
size regulating ring is required? Illustration MO-0113 |
86 mm |
92 mm |
89 mm |
95 mm |
|
D |
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? Illustration MO-0112 |
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 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. |
Disassemble the
entire unit, clean all components, replace any defective gaskets and use
the proper lubricants where required. |
|
C |
When tightening
the lock ring "G" of the device shown in the illustration, two
events are simultaneously accomplished. Which of the following statements
represents these events? Illustration MO-0112 |
The lock ring
insures proper contact between the bowl top and the sliding bowl bottom,
in addition to compressing the disc stack. |
The lock ring
forces the disc stack onto the spindle, providing a positive means of rotation
and locating the bowl top to seal the separation chamber. |
When tightened,
the lock ring allows for movement of the sliding piston and positions the
sliding piston within the bowl bottom. |
The lock ring
insures proper positioning of the disc stack and maintains a positive contact
of the bowl top and bowl bottom. |
|
D |
Which of the following
conditions would be the most probable cause for the 'low oil temperature
after preheater' LED indicators, as shown in the illustration, to be illuminated?
Illustration MO-0127 |
Too high a temperature
in settling tank. |
Improper steam
trap selection. |
Too low a temperature
in day tank. |
Incorrect steam
control valve setting. |
|
B |
On a slow-speed
diesel engine vessel equipped with an ALCAP fuel oil purification system,
what would be a symptom of an opening solenoid valve leaking by? |
An increase in
RPM. |
An increase in
the rate at which the purifier sludge tank is rising. |
An increased in
the voltage at the EPC control cabinet. |
An increased amperage
draw. |
|
C |
Your ship is equipped
with ALCAP heavy fuel oil purifiers. The watchstander reports excessive
water drained from the fuel oil service tank. Which component should he
check? |
The water transducer
located in the dirty oil supply line. |
The bowl RPM. |
The water transducer
located in the clean oil discharge line. |
The closing water
solenoid valve in the fresh water line. |
|
B |
As shown in the
illustration, which of the following conditions would be responsible for
a "low pressure in oil outlet" alarm to be indicated? Illustration
MO-0127 |
Controller set
point changed |
Throughput too
low |
Emergency stop
button not reset |
Separating temperature
too low |
|
B |
If item "F"
begins leaking during operation, which of the following operating conditions
will NOT occur? Illustration MO-0112 |
The unit will
not properly operate and should automatically shut down. |
The oil/water
interface will remain in the same neutral position. |
The oil/water
interface will move outward from the vertical axis of the machine. |
The water seal
will be lost. |
|
A |
While operating
the fuel oil centrifuge shown in the illustration, the bowl fails to open
for sludge ejection. The probable cause is that __________. Illustration
MO-0012 |
the seal ring
on the operating slide is defective |
the operating
water pressure is too high |
the bowl disk
set is clogged |
one or more of
the sludge ports is partially clogged |
|
C |
When reassembling
the bowl of the centrifuge, shown in the illustration, the alignment mark
on the locking ring passes the bowl cover mark in excess of the manufacturer's
specifications. This is due to __________. Illustration MO-0012 |
the paring devices
have been reinstalled in the wrong order |
too many disks
being left out of the bowl during reassembly |
excessive wear
of the locking ring and/or bowl threads |
the disks have
not been placed back in the bowl in numerical sequence |
|
B |
While operating
the fuel oil centrifuge shown in the illustration, the fuel oil is being
continuously ejected with the sludge and the seal water. The probable cause
is the __________. Illustration MO-0012 |
gravity disk inside
diameter is too small |
gravity disk inside
diameter is too large |
back pressure
is too low |
incorrect number
of disks have been place in the disk stack |
|
C |
If the bowl of
a disk type centrifugal purifier when operated as a separator is not primed,
the __________. |
purifier will
act as a clarifier at the discharge ring |
oil solids will
be deposited only at the intermediate top disk |
oil will be lost
through the water discharge ports |
oil has a tendency
to emulsify in the bowl |
|
A |
Which of the following
statements describes what will occur if the annular spaces, indicated by
the letter "K" of the device shown in the illustration, became
restricted? Illustration MO0112 |
The bowl will
fail to close when starting and the unit will not shoot when operating. |
The unit will
not start due to pressure/time delay relays. |
The bowl will
fail to close, but the unit will be capable of shooting while in operation. |
Operating water
will be supplied through port "S". |
|
A |
As Chief Engineer
of a slow speed diesel engine vessel equipped with an ALCAP fuel oil purification
system. You note a definite increase in the rate at which the purifier sludge
tank is rising. One of the first items to check on your system would be
which of the following? |
The opening water
solenoid for leak through. |
The water transducer
located in the dirty oil supply line. |
The RPM of the
bowl. |
The voltage to
the EPC control cabinet. |
|
D |
During the change
over period from residual to distillate fuel the final fuel filters clog
at a decreasing time interval. What is the most likely cause? |
Gasification of
the fuel in the fuel heater. |
Carbonization
of the cylinder oil. |
Stratification
of the fuel in the mixing tank. |
Incompatibility
of the fuels resulting in asphaltenes of the residual fuel precipitating
out. |
|
B |
What operational
difficulties are associated with fuel incompatibility? |
Reduced rack settings. |
Frequent clogging
of final fuel filters and sticking/scuffing of fuel pump plungers and nozzles. |
Carbonization
of the cylinder oil. |
Gasification of the fuel in
the fuel heater. |
|
D |
The principal
hazard to personnel when using a diesel engine fuel nozzle tester is __________. |
electrical shock |
toxic fumes |
explosion |
blood poisoning |
|
B |
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 |
|
C |
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 |
|
B |
The bore of a
diesel engine cylinder describes the __________. |
swept volume of
the cylinder |
inside diameter
of the cylinder |
piston displacement
in the cylinder |
length of the
piston stroke |
|
D |
The cubic inch
(or liter) displacement of a cylinder is determined by the diameter of the
piston and the __________. |
length of the
crankshaft |
volume of the
clearance space |
weight of the
piston |
length of the
stroke |
|
B |
The compression
ratio of a diesel engine refers to the ratio between the __________. |
piston area to
connecting rod length |
cylinder volumes
at top dead center and at bottom dead center |
engine cylinder
size to piston size |
the number of
compression strokes for a given horsepower |
|
D |
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 |
|
B |
The theoretical
minimum compression ratio necessary to ensure compression ignition in a
direct injection diesel engine is __________. |
10 : 1 |
12 : 1 |
16 : 1 |
20 : 1 |
|
A |
Which of the following
relationships exists between the temperatures developed in a combustion
space, and the compression ratio of the engine? |
Higher compression
ratios create higher temperature. |
Higher temperatures
create higher compression ratios. |
Lower temperatures
create higher compression ratios. |
Higher compression
ratios create lower temperatures. |
|
B |
The ratio of the
brake horsepower to the indicated horsepower of a diesel engine is its __________. |
thermal efficiency |
mechanical efficiency |
brake thermal
efficiency |
volumetric efficiency |
|
B |
The most important
factor in engine performance is the actual power output at the end of the
crankshaft available for doing work. This is known as __________. |
indicated horsepower |
brake horsepower |
net horsepower |
friction horsepower |
|
B |
The average pressure
exerted on a piston during each power stroke is termed __________. |
indicated horsepower |
mean effective
pressure |
exhaust back pressure |
compression pressure |
|
D |
The thermal energy
produced by an internal combustion engine is transformed into __________. |
combustion energy |
internal energy |
external energy |
mechanical energy |
|
B |
What determines
the number of events occurring in a cycle of operation in an internal combustion
engine? |
Crankshaft revolution |
Method of air
charging a cylinder and expelling exhaust gases |
Distance a piston
travels during a stroke |
Number of pistons |
|
A |
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. |
|
C |
The highest pressure
in a diesel engine cylinder normally occurs __________. |
at TDC |
before TDC |
after TDC |
during air starting |
|
C |
Modern marine
diesel engines equipped with mechanical fuel injection operate on a combustion
cycle which is __________. |
entirely constant
volume |
entirely constant
pressure |
a combination
of constant volume and constant pressure |
a combination
of constant temperature and constant pressure |
|
A |
The load is always
placed on the lower half of the main bearings in a/an __________. |
two-stroke/cycle
engine |
four-stroke/cycle
engine |
reverse cycle
engine |
double acting
engine |
|
B |
The camshaft drive
is designed to maintain proper camshaft speed relative to crankshaft speed.
In maintaining this relationship, the camshaft drive causes the camshaft
to rotate at __________. |
one-half crankshaft
speed in a two-stroke cycle diesel engine |
crankshaft speed
in a two-stroke cycle diesel engine |
two times crankshaft
speed in a two-stroke cycle diesel engine |
one-fourth times
crankshaft speed in a four-stroke cycle diesel engine |
|
B |
Which of the terms
listed below represents the operational speed at which excessive engine
vibration is created? |
Non-harmonic speed. |
Critical speed. |
Maximum speed. |
Design maximum
speed. |
|
A |
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 |
|
B |
The pressure-volume
diagrams illustrated are of four internal combustion engine cycles. Which
one represents the theoretical diesel cycle? Illustration MO-0102 |
A |
B |
C |
D |
|
B |
If point #1 in
the diagram shown is the beginning of gas compression, which of the cycles
listed is being illustrated? Illustration MO-0036 |
Otto |
Diesel |
Gas Turbine |
Rankine |
|
A |
When calculating
the indicated power developed in a diesel engine cylinder, 1 horsepower
is equivalent to '33,000 foot-pounds per minute'. What conversion factor
would be used if the values are based on metric 'kilogram-meters per minute'? |
4500 kg-meters
per minute = 1 HP |
5500 kg-meters
per minute = 1 HP |
11000 kg-meters
per minute = 1 HP |
16500 kg-meters
per minute = 1 HP |
|
B |
What is the average
piston speed of a five cylinder low-speed engine with a bore of 29.5 inches
(75 cm), a stroke of 63 inches (160 cm), and a rated speed of 123 RPM? |
645 ft/min (196
m/min) |
1291 ft/min (393
m/min) |
2582 ft/min (787
m/min) |
7749 ft/min (2362
m/min) |
|
A |
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 |
|
C |
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 |
|
B |
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 |
|
B |
The speed of the
camshaft in a two-stroke/cycle diesel engine, running at 950 RPM, is __________. |
475 RPM |
950 RPM |
1900 RPM |
2400 RPM |
|
A |
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 |
|
B |
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 |
|
A |
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
o |
4644 kW
o |
7296 kW
o |
9290 kW |
|
B |
Line "P"
in the illustration is the __________. Illustration MO-0126 |
line of maximum
horsepower |
propeller curve
|
line of maximum
efficiency
|
exponential line |
|
D |
Which of the following
conditions will cause the engine to operate in area "A" of the
diagram shown in the illustration? Illustration MO-0126 |
Fouled hull
|
Damaged propeller
blades |
Inclement weather |
Excessive propeller
cavitation |
|
C |
The diagram shown
in the illustration may be used to determine the proper operation of the
engine. Which of the following statements represents an accurate interpretation
of the diagram? Illustration MO-0126
|
The engine may
be operated in any area of the diagram provided steps are taken to reposition
the load indicator. |
Operation within
area "B" is permitted for extended time periods provided no changes
are made to the air intake system. |
Ideally the engine
should be operated in area "A", however, it is permissible to
intermittently operate the engine in area "B".
|
Assuming the load
indicator reads 90% and the engine speed is at 80% the engine can be operated
until maintenance requirements become apparent.
National Maritime Center Assistant Engineer-DDE
.
13. (2.3.1.6-4) Which of the following conditions would NOT be considered
a valid reason for the diesel engine to operate in the area indicated by
letter "B" shown in the illustration? Illustration MO-0126 |
|
D |
Which of the following
conditions would NOT be considered a valid reason for the diesel engine
to operate in the area indicated by letter "B" shown in the illustration?
Illustration MO-0126
|
Operating the
vessel in shallow water
|
Operating with
a fouled or damaged propeller |
Operating the
vessel against high winds and current |
Operating with
minimal hull drag and under light draft |
|
D |
In the pressure-volume
diagram shown in the illustration, fuel injection occurs at point __________.
Illustration MO-0035 |
e |
d |
f |
c |
|
D |
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 |
|
A |
The indicator
card shown in the illustration is produced with a/an __________. Illustration
MO-0108 |
rotating drum |
sliding camshaft |
oscillating drum |
balanced-diaphragm
indicator |
|
D |
On the indicator
card shown in the illustration, lines 'A' and 'B' indicate __________. Illustration
MO-0108 |
the end of ignition |
bottom dead center |
the end of injection |
top dead center |
|
C |
In the pressure-volume
diagram, shown in the illustration, what occurs between points "e"
and "f"? Illustration MO-0035 |
The exhaust valve
closes. |
The intake ports
close. |
Pressure in the
cylinder decreases. |
Volume in the
cylinder decreases. |
|
C |
In the pressure-volume
diagram, shown in the illustration, the volume line is divided into 16 units
indicating __________. Illustration MO-0035 |
a cylinder volume
of 166 cubic inches |
compression pressure
is 1600 PSI |
a 16 to 1 compression
ratio |
16° of crankshaft
motion between lines A and B |
|
A |
In the pressure-volume
diagram shown in the illustration, curve 'A-d' indicates __________. Illustration
MO-0035 |
combustion at
approximately constant pressure |
opening of exhaust
valves |
fuel injection
after dribble |
start of fuel
injection |
|
A |
In the pressure-volume
diagram, shown in the illustration, what is indicated to have occurred by
the line connecting points 'd' and 'e'? Illustration MO-0035 |
The combustion
gases have expanded. |
The crankshaft
has rotated 90°. |
Pressure and volume
have increased. |
The fuel/air charge
is compressed. |
|
A |
On the cylinder
indicator diagram illustrated, the dotted line indicated as "L"
is describing the __________. Illustration MO-0033 |
cylinder pressure
without injection |
firing pressure
at 90 degrees crank angle |
beginning of compression |
power expansion
curve |
|
A |
Which of the indicator
diagrams illustrated depicts the condition that should be corrected by retarding
only the timing? Illustration MO-0029 |
A |
B |
C |
D |
|
A |
On the indicator
card shown in the illustration, lines 'A' and 'B' indicate __________. Illustration
MO-0108 |
top dead center |
bottom dead center |
the end of injection |
the end of ignition |
|
D |
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 |
|
D |
In a diesel engine,
after ignition of the fuel occurs, but before the piston reaches TDC, there
is little change in the cylinder __________. |
temperature |
pressure |
energy |
volume |
|
C |
Turbulence of
the compressed air charge in a diesel engine cylinder increases __________. |
ignition lag |
piston side thrust |
the efficiency
of fuel combustion |
compression pressure |
|
A |
The greatest turbulence
in a diesel engine cylinder is created by the __________. |
shape of the combustion
chamber |
fuel injection
spray pattern |
cylinder swept
volume |
degree of penetration
of the fuel oil droplets |
|
C |
The main operating
characteristic of diesel engines which distinguishes them from other internal
combustion engines is the __________. |
method of supplying
air |
cooling system |
method of igniting
fuel |
valve operating
mechanism |
|
B |
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 |
|
C |
The formation
of carbon monoxide in diesel exhaust gases is reduced by __________. |
spraying water
into the exhaust pipe |
keeping the exhaust
system free of carbon deposits |
maintaining proper
combustion and scavenging |
avoiding light
load operation |
|
D |
Theoretical perfect
combustion in a diesel engine yields by-products of __________. |
aldehydes and
carbon dioxide |
water vapor and
carbon monoxide |
nitrogen and carbon
monoxide |
water vapor and
carbon dioxide |
|
D |
The minimum speed
an engine must attain before ignition can occur depends upon __________. |
the type and size
of the engine
o |
the condition
of the engine |
ambient temperature |
All of the above. |
|
B |
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 |
|
D |
What is the term
given to the process of breaking up fuel oil into very fine particles for
better combustion? |
Settling |
Straining |
Spraying |
Atomizing |
|
B |
Proper atomization
of fuel in diesel engine combustion chambers will __________. |
affect the injection
pressure |
improve combustion |
reduce compression
pressure |
decrease power
output |
|
B |
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 |
|
C |
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 |
|
A |
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 |
|
B |
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 |
|
C |
According to the
diagram shown in the illustration, the lube oil system can best be described
as a __________. Illustration MO-0007 |
bypass system |
dry sump system |
wet sump system |
shunt system |
|
D |
On most modern
diesel engines, the main and connecting rod bearings receive their lubricating
oil by __________. |
banjo feed |
splash feed |
gravity feed |
pressure feed |
|
D |
A well-lubricated
bearing surface always appears __________. |
well knurled |
slightly streaked |
lightly glazed |
highly polished |
|
A |
Proper lubrication
of the main bearings is more easily obtained in a single acting fourstroke/cycle
diesel engine than in a single acting two-stroke/cycle diesel engine because
__________. |
bearing pressure
in a four-stroke/cycle single acting diesel engine is continually reversed |
bearing pressure
in a two-stroke/cycle single acting diesel engine is continually reversed |
the maximum bearing
pressure is higher in a single acting two-stroke/cycle diesel engine |
two-stroke/cycle
diesel engines require more complicated lubrication piping |
|
C |
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 |
|
C |
Which of the following
should always be checked prior to starting a diesel engine? |
Air filters |
Fuel oil strainers |
Crankcase oil
level |
Pyrometer readings |
|
C |
Which of the listed
diesel engine operating conditions should be checked immediately after any
diesel engine is started? |
Exhaust temperature |
Lube oil level |
Lube oil pressure |
Water level in
the expansion tank |
|
C |
The most crucial
time for any bearing with regards to diesel engine lubrication is __________. |
during periods
of low load |
during first warm
up |
during initial
starting |
after load reversals |
|
D |
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 |
|
C |
Before starting
a diesel engine that has an engine driven lube oil pump, the operator 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 |
|
C |
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 |
|
C |
Which of the following
devices is normally provided to prevent oil starvation in a diesel engine
lubrication system utilizing the 'full flow' principle? |
Duplex strainer |
Three-way valve |
Pressure relief
bypass line around the filter |
Mechanical straining
filter |
|
D |
The lube oil pump
used in a diesel engine is normally a __________. |
volute pump |
centrifugal pump |
diaphragm pump |
gear pump |
|
A |
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 |
|
D |
Two important
considerations for the proper lubrication of a diesel engine include, the
delivery of the oil in sufficient amount, and the __________. |
cetane number |
pour point |
viscosity temperature |
quality of the
oil |
|
D |
A diesel engine
should use which type of lubricating oil? |
Low viscosity |
Cutting oil |
High grade vegetable
oil |
Detergent oil |
|
A |
The highest indicated
lube oil pressure in a diesel engine should be expected when the engine
oil is __________. |
cold at idle |
warm at idle |
warm at full speed |
warm at full speed
and no fuel dilution exists |
|
C |
The TBN value
of diesel engine lube oil refers to its ability to __________. |
resist changes
in viscosity with changes in temperature |
resist emulsification |
neutralize acids |
resist oxidation
at high temperatures |
|
C |
Which lubricating
oil additive is used in diesel engines to reduce the tendency for sludge
and varnish to form on the engine parts? |
Flash point improvers |
Pour point improvers |
Inhibitors |
Foam suppressors |
|
C |
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 |
|
D |
The lube oil strainer
shown in the illustration is used on the reduction gear of a mid-size diesel
engine. The strainer elements consist of __________. Illustration MO-0057 |
pleated paper |
wire mesh |
fibrous braid |
metal disks |
|
C |
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 |
|
C |
A magnetic strainer
is primarily used in diesel engine reduction gear oil systems to remove
small particles of __________. |
copper |
Babbitt |
ferrous materials |
acidic materials |
|
D |
Where would a
coarse screen wire-mesh strainer normally be found on a diesel engine lubrication
system? |
pump discharge
line |
gravity tank inlet
line |
filter bypass
return line |
pump suction line |
|
C |
How is the illustrated
strainer element cleaned during engine operation? Illustration MO-0057 |
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. |
|
C |
What type of engine
lubrication oil filter system sends filtered oil directly to the high pressure
supply gallery? |
centrifugal purifier
system |
bypass system |
shunt system |
batch system |
|
C |
In a by-pass type
lubrication system for a diesel engine, the dirty oil line to the filter
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 |
|
D |
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 |
|
A |
The lube oil cooler
is located after the lube oil filter in order for __________. |
the filter to
operate more efficiently |
the lube oil cooler
to be bypassed |
positive lube
oil pump suction to be assured |
galvanic action
in the cooler to be minimized |
|
C |
Which of the following
statements is true concerning a main diesel engine oil cooler? |
The oil temperature
is less than the cooling water temperature. |
The oil pressure
is less than the cooling water pressure. |
The oil pressure
is greater than the cooling water pressure. |
The oil flow control
valve is always installed in the oil input line. |
|
D |
Heat exchangers
are most commonly found in a small auxiliary diesel engine __________. |
fuel oil system |
governing system |
air starting system |
lube oil system |
|
B |
Reduction gear
lube oil temperatures for keel cooler installations are generally __________. |
lower than raw
water cooled installations |
higher than raw
water cooled installations |
identical to raw
water cooled installations |
lower than raw
water cooled installations, but the pressure will be higher |
|
C |
One advantage
of a vacuum feed sight glass indicator used on cylinder lubricators over
the discharge side liquid filled type sight glass is __________. |
there are fewer
moving parts |
adjustments are
not required |
better visual
metering adjustment |
a lower grade
of cylinder oil may be used |
|
D |
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 |
|
C |
The rate of cylinder
lubricating oil metered to each cylinder of a large, low-speed, main propulsion
diesel engine is __________. |
the same, whether
at sea, or during maneuvering |
adjusted during
each hour of operation while at constant RPM |
reduced during
periods of low load operation |
lower at sea than
while maneuvering |
|
C |
The device shown
in figure "A" of the illustration is used to __________. Illustration
MO-0042 |
inject fuel into
the cylinder |
admit starting
air to the cylinder |
provide lubrication
to the cylinder |
provide an adapter
to obtain combustion pressure readings |
|
A |
The illustrated
device is used to __________. Illustration MO-0050 |
supply cylinder
lubricating oil to the engine |
meter fuel oil
to the injectors |
admit the correct
amount of starting air to the cylinders in proper order |
actuate exhaust
valves in the correct sequence |
|
C |
The component
labeled as part #20 in the illustration is used to __________. Illustration
MO-0050 |
meter the amount
of oil flow to the cylinder lubricating quill |
adjust the timing
of the cylinder lubricating oil to the cylinder |
indicate the quantity
of oil flow to the cylinder |
prevent the backflow
of oil and combustion gases |
|
C |
The adverse effects
of burning high sulfur fuel can be compensated for by using a cylinder oil
having sufficient __________. |
dispersant additives |
floc point depressive
additives |
alkalinity |
ignition quality |
|
A |
The device shown
in the illustration is classified as a/an __________. Illustration MO-0008 |
comparator type
mist detector |
exhaust gas vapor
condenser |
Ringleman exhaust
gas analyzer |
reflective type
explosion meter |
|
C |
The device shown
in the illustration is a __________. Illustration MO-0008 |
rotary type mist
detector, designed for use in four-stroke, high speed diesel engines |
photo-electric,
explosive gas indicator, for use in high speed, two-stroke, trunk type piston
engines |
comparator type
mist detector for large low speed, crosshead type engines |
level type explosimeter,
for small medium speed, trunk piston type engines |
|
A |
The purpose of
an oil mist detector in a main propulsion diesel engine is to warn of __________. |
a possible overheated
bearing |
excessively high
crankcase vacuum |
low cylinder oil
pressure |
excessive carbon
buildup in the lube oil |
|
D |
Which of the following
problems could develop due to the accumulation of oil vapors in the crankcase
of a diesel engine? |
Reduced lubrication |
Poor fuel economy |
Combustion knock |
Crankcase explosion |
|
D |
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 |
|
A |
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 |
|
D |
Shaker, circulation,
and spray are the three general methods used in __________. |
pre-injection
fuel oil treatment |
lube oil filtration |
lube oil purification |
piston cooling |
|
A |
The upper piston
rings in large, slow-speed, two-stroke/ cycle diesel engines are most effectively
lubricated by oil __________. |
fed from mechanical
lubricators |
thrown off from
the main bearings |
supplied from
wick fed drip lubricators |
flow from a centrifugal
or banjo oiler |
|
D |
Wristpin bearings
are difficult to lubricate because of their oscillating motion and __________. |
their free-floating
design |
their relatively
small size |
the reciprocating
motion of the piston |
their position
in the lubrication system |
|
C |
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 |
|
B |
Which of the following
test indicators should be considered the most significant factor in determining
as to whether or not a diesel generator's lube oil should be drained and
renewed? |
The oil appears
black in color. |
An extremely high
neutralization number. |
An extremely low
precipitation number. |
An increase in
flash point. |
|
C |
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 |
|
C |
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 |
|
A |
What type of engine
lubrication oil filter system sends filtered oil directly to the high pressure
supply gallery? |
shunt system |
batch system |
centrifugal purifier
system |
bypass system |
|
A |
In a by-pass type
lubrication system for a diesel engine, the dirty oil line to the filter
should be taken from the___________. |
bottom of the
lube oil sump |
lube oil pump
discharge line |
lube oil pump
suction line |
outlet from the
lube oil header |
|
A |
The device shown
in the illustration is classified as a/an __________. Illustration MO-0008 |
comparator type
mist detector |
Ringleman exhaust
gas analyzer |
reflective type
explosion meter |
exhaust gas vapor
condenser |
|
C |
The device shown
in the illustration is a __________. Illustration MO-0008 |
level type explosimeter,
for small medium speed, trunk piston type engines |
rotary type mist
detector, designed for use in four-stroke, high speed diesel engines |
comparator type
mist detector for large low speed, crosshead type engines |
photo-electric,
explosive gas indicator, for use in high speed, two-stroke, trunk type piston
engines |
|
A |
The purpose of
an oil mist detector in a main propulsion diesel engine is to warn of __________. |
a possible overheated
bearing |
low cylinder oil
pressure |
excessively high
crankcase vacuum |
excessive carbon
buildup in the lube oil |
|
C |
Which of the following
problems could develop due to the accumulation of oil vapors in the crankcase
of a diesel engine? |
Poor fuel economy |
Combustion knock |
Crankcase explosion |
Reduced lubrication |
|
C |
One advantage
of a vacuum feed sight glass indicator used on cylinder lubricators over
the discharge side liquid filled type sight glass is __________. |
a lower grade
of cylinder oil may be used |
adjustments are
not required |
better visual
metering adjustment |
there are fewer
moving parts |
|
B |
Mechanical lubricators
for diesel engine cylinders are usually small reciprocating pumps which
are __________. |
operated manually
once each hour |
adjustable to
meet lubrication requirements |
placed into operation
only at maximum load |
operated until
the engine has started |
|
D |
The rate of cylinder
lubricating oil metered to each cylinder of a large, low-speed, main propulsion
diesel engine is __________. |
adjusted during
each hour of operation while at constant RPM |
lower at sea than
while maneuvering |
the same, whether
at sea, or during maneuvering |
reduced during
periods of low load operation |
|
B |
The device shown
in figure "A" of the illustration is used to __________. Illustration
MO-0042 |
admit starting
air to the cylinder |
provide lubrication
to the cylinder |
inject fuel into
the cylinder |
provide an adapter
to obtain combustion pressure readings |
|
A |
The illustrated
device is used to __________. Illustration MO-0050 |
supply cylinder
lubricating oil to the engine |
actuate exhaust
valves in the correct sequence |
meter fuel oil
to the injectors |
admit the correct
amount of starting air to the cylinders in proper order |
|
A |
The component
labeled as part #20 in the illustration is used to __________. Illustration
MO-0050 |
indicate the quantity
of oil flow to the cylinder |
adjust the timing
of the cylinder lubricating oil to the cylinder |
meter the amount
of oil flow to the cylinder lubricating quill |
prevent the backflow
of oil and combustion gases |
|
B |
The adverse effects
of burning high sulfur fuel can be compensated for by using a cylinder oil
having sufficient __________. |
ignition quality |
alkalinity |
dispersant additives |
floc point depressive
additives |
|
D |
A 'Blotter test'
is a test performed on the lube oil of a diesel engine which can determine
__________. |
the flash point
of the oil |
the specific gravity
of the oil |
the TBN number
of the oil |
a change in the
oils viscosity |
|
A |
If the analysis
of used lube oil indicates a high content of iron particles, this could
indicate __________. |
excessive ring
and liner wear |
inadequate air
filtration |
excessive cooling
of lubricating oil |
corrosive deterioration
of a bearing |
|
A |
A decrease in
the flash point of diesel engine lube oil indicates the lube oil has become
__________. |
diluted with fuel
oil |
contaminated with
sludge |
diluted with water |
contaminated with
carbon |
|
A |
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 __________. |
water contamination
of the lube oil system |
proper break-in
wear |
improper break-in
wear |
relocation of
the overlay flashing |
|
A |
While underway,
a slow-speed diesel engine lube oil sump level slowly begins to decrease.
Which of the following should be checked? |
The lubricating
oil cooler for leakage into the cooling system. |
The standby lube
oil pump to ensure it is not operating. |
The tank heating
coils to ensure they are secured. |
The piston oil
scraper rings for excessive wear. |
|
A |
What could cause
the bypass valve in a full-flow lubrication system to open? |
Clogged filter
element |
Bypass valve setting
is too high |
Check valve stuck
open |
Fuel dilution
of the lubricant |
|
D |
A dirty lube oil
strainer can result in __________. |
excessive oil
consumption |
low lube oil temperature |
crankcase dilution |
low bearing oil
pressure |
|
C |
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 |
|
C |
Oil oxidation,
as a result of excessively high lube oil temperature, is harmful to a diesel
engine because __________. |
lube oil viscosity
is always decreased |
oil foaming will
occur |
corrosive by-products
are usually formed |
large quantities
of oil are consumed |
|
A |
Which of the following
effects will excessively cold lube oil have on the operation of a diesel
engine? |
The engine will
crank slowly and may fail to start. |
The engine will
overspeed when started. |
The fuel oil supply
will become diluted resulting in rough running. |
The cooling system
will overheat causing the engine to stall. |
|
C |
Oil analysis for
a crosshead type diesel engine indicates the TBN of the crankcase lubricating
oil is increasing. This is most likely associated with which of the following? |
Excessive purification
temperatures |
Increase in the
water content of the crankcase lubricating oil |
Leaking stuffing
boxes introducing cylinder lubricating oil into the crankcase |
Bearing wear |
|
D |
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 |
|
A |
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 |
|
B |
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. |
|
D |
The time between
injection and ignition of the fuel is known as __________. |
turbulence lag |
after burning
ratio |
injection lag |
ignition delay |
|
B |
When is fuel injected
into a cylinder of diesel engines? |
Before air in
the cylinder is compressed. |
After air in the
cylinder is compressed. |
After combustion
gases in the cylinder have expanded. |
As air is taken
into the cylinder. |
|
C |
Which area of
the indicator diagram illustrated, indicates the ignition delay period in
a diesel engine cylinder? Illustration MO-0033 |
G |
H |
J |
K |
|
A |
The pressure in
an operating diesel engine cylinder continues to rise for a short period
after the piston passes top dead center as a result of the __________. |
expansion during
the combustion process |
exhaust and intake
valves just closing |
maximum compression
pressure is just being attained |
fuel injection
occurring at that point and combustion begins |
|
C |
The rate of pressure
rise during the period following fuel ignition in a diesel engine is influenced
by the length of the ignition delay period and the __________. |
valve overlap |
volumetric efficiency |
turbulence of
the air charge |
fuel efficiency |
|
D |
On the cylinder
indicator diagram illustrated, the maximum rise in pressure occurs during
the period labeled as __________. Illustration MO-0033 |
J |
K |
G |
H |
|
D |
Which statement
about diesel engine combustion is true? |
Combustion does
not begin until the piston starts down on the power stroke. |
Maximum combustion
pressure is reached before TDC. |
Turbulence in
the cylinder causes a delay in ignition. |
Maximum cylinder
firing pressure is not developed until the piston passes TDC. |
|
C |
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 |
|
C |
On the cylinder
indicator diagram illustrated, the dotted line indicated as "L"
is describing the __________. Illustration MO-0033 |
power expansion
curve |
beginning of compression |
cylinder pressure
without injection |
firing pressure
at 90 degrees crank angle |
|
C |
Which area of
the indicator diagram illustrated, indicates the afterburning period in
a diesel engine cylinder? Illustration MO-0033 |
J |
H |
K |
G |
|
D |
Item labeled "L"
as shown in section 6 of the illustration is identified as the __________.
Illustration MO-0025 |
air filter |
exhaust manifold |
non return scavenge
valve |
after cooler |
|
B |
While underway,
which of the following would be the FIRST step in reversing a direct reversing
large, slow-speed, main propulsion, diesel engine? |
Manually trip
the over speed device. |
Set the fuel rack
to zero. |
Disengage the
safety interlock. |
Slide the camshaft
to the neutral position. |
|
C |
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 |
|
D |
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 |
|
D |
Which of the following
procedures should be carried out when a large, low-speed, diesel engine
is operated with one cylinder secured? |
Lubrication to
the defective cylinder should be increased.
o |
Cooling water
temperature to the engine should be increased. |
Only the turbocharger
speed should be reduced. |
Engine speed should
be reduced. |
|
C |
In the slow speed
diesel engine shown in the illustration, the part labeled "E"
is the __________. Illustration MO-0003 |
high pressure
lube oil line |
low pressure lube
oil line |
high pressure
fuel line
|
low pressure fuel
line |
|
D |
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? |
The way of the
vessel |
Flywheel inertia |
Securing cylinder
lubricators |
Admission of reversing
start air |
|
B |
The line identified
as "I" in the illustration is used to __________. Illustration
MO-0066 |
deliver fuel oil
to the injector |
supply lubricating
oil for actuating the exhaust valve |
deliver cooling
water to the exhaust valve actuating device |
exhaust gas and
vapors from the power cylinder |
|
B |
Which letter represents
the scavenging air system non-return valve in the illustration? Illustration
MO-0003 |
Q |
P |
U |
W |
|
D |
Valve cages are
used on some large diesel engines to __________. |
reduce wear on
the valve stem |
permit the use
of alloy valve seat materials |
reduce heat transfer
from the valve seat |
facilitate valve
removal for servicing |
|
B |
In the diesel
engine shown in the illustration, the purpose of the part labeled "P"
is to __________. Illustration MO-0003 |
boost the scavenge
air pressure |
ensure one way
air flow into the air header |
provide turbulence
in the scavenge air |
cool the scavenge
air |
|
A |
In the illustrated
engine, the fuel camshaft gear drive housing is indicated as letter __________.
Illustration MO-0003 |
F |
Z |
G |
B |
|
B |
A diesel engine
crankcase ventilation system __________. |
prevents spark
generation |
removes combustible
gases |
determines the
level of combustible gases |
provides inert
gas generation in crankcase |
|
A |
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 |
|
C |
The part labeled "X"
shown in the illustration is a __________. Illustration MO-0003 |
fuel line |
water line |
lube oil line |
control linkage |
|
D |
According to the
illustration, fuel delivery to the cylinder is terminated and controlled
with the component that is identified as the letter __________. Illustration
MO-0097 |
C |
H |
K |
I |
|
A |
Which of the following
processes is indicated by the flow arrows shown in the illustration? Illustration
MO-0026 |
Relief of excessively
high pressure gases from the cylinder. |
Cooling water
bypass flow to the heat sink. |
Return flow of
excess fuel oil from the injector. |
Return air flow
during start-up upon achieving ignition. |
|
A |
Which of the listed
design features is most common with a two-stroke cycle, low-speed main propulsion
diesel engine? |
Piston rod and
crosshead construction |
90 degree 'V'
configuration |
Double acting
trunk type pistons |
Single reduction
gearing |
|
A |
There are two
glands provided where the piston rod exits the cylinder shown in the illustration.
The purpose of the top gland is to __________. Illustration MO-0083 |
seal against scavenge
air leakage |
prevent crankcase
oil leaking out |
maintain crankcase
vacuum |
maintain crankcase
pressure |
|
D |
The diesel engine
shown in the illustration, the exhaust manifold is indicated by the letter
__________. Illustration MO-0003 |
A |
B |
P |
U |
|
C |
The opening of
an exhaust valve on a modern, large, low-speed, main propulsion diesel engine,
may be actuated by __________. |
direct action
of the overhead cam shaft |
compressed air
pressure |
hydraulic "push
rods" |
direct action
of the main piston moving down |
|
B |
The exhaust ports
shown in the illustration are identified with the letter " ".
Illustration MO-0003 |
B |
Q |
T |
U |
|
D |
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 |
|
B |
The closing of
the exhaust valves used on a modern, large, low-speed, main propulsion diesel
engine may be directly provided by __________. |
mechanical push
rods |
compressed air
pressure |
hydraulic pressure |
exhaust gas pressure |
|
A |
The insertion
of shims between the foot of a marine type connecting rod and a bearing
box would result in __________. |
increased compression
ratio |
decreased compression
ratio |
increased bearing
clearance |
decreased bearing
clearance |
|
D |
In the diesel
engine illustrated, what part is under compression when firing is taking
place in a particular cylinder? Illustration MO-0003 |
Tie rod |
Piston rod nut |
Lubrication telescopes |
Piston rod |
|
C |
In the pressure-volume
diagram shown in the illustration, the atmospheric pressure line is indicated
by line __________. Illustration MO-0035 |
A |
B |
C |
de |
|
A |
Which of the indicator
diagrams illustrated depicts the condition that should be corrected by retarding
only the timing? Illustration MO-0029 |
A |
B |
C |
D |
|
D |
In diesel engines
designed with a crosshead, the motion of the piston rod can be described
as __________. |
reciprocating
at the crank pin, rotary at the piston pin |
straight rotation |
reciprocating
at the piston pin, rotary at the crank pin |
straight reciprocation |
|
D |
Which of the indicator
diagrams illustrated indicates the condition that should be corrected by
retarding the timing, and the fitting of thicker shims to the connecting
rod? Illustration MO-0029 |
A |
B |
C |
D |
|
B |
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 |
|
D |
Which of the bearings
listed below is most widely used for the main and connecting rod bearings
of a modern high-speed diesel engine? |
Poured Babbitt,
self-aligning |
Split roller |
Steel-lined |
Precision insert |
|
D |
Device "E"
shown in the illustration is known as the __________. Illustration MO-0122 |
lube oil manifold |
extrusion tube
assembly |
over speed trip
shaft |
fuel manifold |
|
A |
The injector rack
of the diesel engine shown in the illustration is indicated by the component
labeled __________. Illustration MO-0122 |
"G" |
"E" |
"F" |
"B" |
|
C |
The fuel injector
for the diesel engine shown in the illustration, is identified as __________.
Illustration MO-0122 |
"M" |
"Z" |
"19" |
"H" |
|
B |
Which letter represents
the exhaust gas exit point for the diesel engine shown in the illustration?
Illustration MO-0122 |
"J" |
"V" |
"N" |
"K" |
|
B |
The diesel engine
water inlet jumper illustrated is represented by the letter or number __________.
Illustration MO-0122 |
"W" |
"M" |
"N" |
"14" |
|
D |
The water inlet
manifold for the diesel engine shown in the illustration is represented
by the letter or number__________. Illustration MO-0122 |
"W" |
"M" |
"13" |
"N" |
|
A |
The main lube
oil manifold, for the diesel engine shown in the illustration, is represented
by the letter or number __________. Illustration MO-0122 |
"O" |
"N" |
"17" |
"11" |
|
B |
Component 'U'
of the diesel engine shown in the illustration is called the __________.
Illustration MO-0122 |
frequency tuner |
crankshaft counterweight
o |
frame stiffener
o |
main bearing support
assembly |
|
B |
The diesel engine
component labeled "1", shown in the illustration is called a/an
__________. Illustration MO-0122 |
external thread |
exhaust valve
spring
|
inlet valve spring
|
conical speed/surge
prevention device |
|
D |
The inlet valves
for the diesel engine shown in the illustration are indicated by the letter
or number __________. Illustration MO-0122 |
"2"
o |
"H" |
"19" |
none of the above
are correct |
|
D |
Which of the components
listed is only found in an opposed piston engine? |
Exhaust valves |
Scavenging ports |
Combustion chambers |
Upper and lower
crankshafts |
|
D |
The diesel engine
component labeled "3", shown in the illustration is called the
__________. Illustration MO-0122 |
scavenging air
space |
cylinder liner |
head valve assembly |
cylinder head |
|
D |
The diesel engine
component labeled "5", shown in the illustration is known as the
__________. Illustration MO-0122 |
heat sink space
o |
piston crown |
connecting rod
end assembly |
piston thrust
washer |
|
A |
The diesel engine
wrist pin in the illustration is indicated by the component labeled __________.
Illustration MO-0122 |
"7" |
"G" |
"S" |
"17" |
|
A |
The diesel engine
connecting rods shown in the illustration are distinctively named____________.
Illustration MO-0122 |
fork and blade |
male and female |
hook and nail |
left hand and
right hand |
|
B |
What is the function
of component "13" shown in the illustration? Illustration MO-0122 |
The inlet jumper
directs cooling water to the cylinder liner. |
The device delivers
the oil for piston cooling, in addition to liner lubrication.
o |
The water pipe
is the mechanism in which the 'shaker' method of piston cooling is accomplished.
o |
The sample tube
monitors the cylinder for evidence of piston blow by. |
|
A |
Item '17' in the
illustration is the dipstick. When should the length of the dipstick be
changed? Illustration MO-0122 |
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. |
|
A |
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 |
|
A |
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 crank
arm and crankpin |
between the master
and link connecting rods |
|
D |
Which of the listed
cylinder head design features is shown in the illustration? Illustration
MO-0013 |
The valve cages
are provided for the exhaust valves. |
The engine is
equipped with a dry liner. |
A gastight seal
is provided by a gasket between the cylinder head and cylinder liner. |
The engine cylinder
head is fitted with replaceable valve seats. |
|
A |
Which letter represents
the top deck (valve) cover of the engine shown in the illustration? Illustration
MO-0122 |
A' |
H' |
8' |
None of the above
are correct. |
|
B |
Which of the following
represents the diesel engine camshaft shown in the illustration and its
relative rotating speed? Illustration MO-0122 |
"B"
is the camshaft and it rotates at one half of the crankshaft speed. |
"B"
is the camshaft and its rpm will match that of the flywheel. |
"T"
is the camshaft and its speed equals crankshaft speed. |
"Y"
is the main camshaft drive and rotates at crankshaft speed. |
|
C |
The diesel engine
rocker arms shown in the illustration serve to __________. Illustration
MO-0122 |
convert rotational
energy to reciprocating pressures |
operate the exhaust
and starting valves |
open the exhaust
valves and operate the unit injectors |
open the intake
and exhaust valves |
|
D |
The rocker arms
of the diesel engine shown in the illustration are indicated by __________.
Illustration MO-0122 |
"D" |
"C" |
"B" |
"C"
and "Y" |
|
A |
Which of the listed
design features is most common with a two-stroke cycle, low-speed main propulsion
diesel engine? |
Piston rod and
crosshead construction |
90 degree 'V'
configuration |
Double acting
trunk type pistons |
Single reduction
gearing |
|
A |
If the speed of
the propeller is 135 RPM, the speed of the engine camshaft shown in the
illustration will be __________. Illustration MO-0003 |
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 |
|
B |
In the illustrated
engine, the main camshaft controls the timing of which of the following
components? Illustration MO-0003 |
exhaust valves |
fuel pumps |
Intake valves |
All of the above. |
|
B |
The lower end
of the piston rod, shown in the illustration, is fitted into the __________.
Illustration MO-0003 |
crank pin |
crosshead |
piston pin |
crosshead guide |
|
B |
There are two
glands provided where the piston rod exits the cylinder shown in the illustration.
The purpose of the top gland is to __________. Illustration MO-0083 |
prevent crankcase
oil leaking out |
seal against scavenge
air leakage |
maintain crankcase
vacuum |
maintain crankcase
pressure |
|
C |
The piston rod
scraper box incorporated in a two-stroke/cycle, crosshead diesel engine
serves to __________. |
eliminate the
necessity for an oil scraper ring |
prevent side thrust
and cylinder scoring |
prevent sludge
and dirty oil from entering the crankcase |
scrape oil and
carbon deposits off the cylinder walls |
|
C |
The item labeled "T"
as shown in figure 4 of the illustration is identified as the __________.
Illustration MO-0025 |
after cooler |
air blower |
exhaust gas turbine |
air filter |
|
B |
In what figure
of the illustration does the crosshead experience the greatest side thrust?
Illustration MO-0025 |
Figure 1 |
Figure 2 |
Figure 6 |
Figure 5 |
|
C |
Telescopic pipes
which are attached to water cooled pistons of large, slow-speed, main propulsion
diesel engines are designed to __________. |
overcome excessive
crankcase pressure |
prevent excessive
lube oil temperature |
allow piston cooling
water to efficiently enter the piston despite its reciprocating piston motion
without contaminating the engine lube oil |
prevent contamination
of the cylinder cooling water with engine lube oil |
|
B |
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 |
|
B |
The diesel engine
shown in the illustration utilizes the type of cylinder construction identified
as __________. Illustration MO-0007 |
a dry liner |
a wet liner |
integral with
a removable sleeve |
integral with
a non- removable sleeve |
|
D |
Why are some diesel
engine cylinder liners plated on the wearing surface with porous chromium? |
The chromium will
not wear out the piston rings. |
The chromium strengthens
the liners in the way of the scavenging air ports. |
Chromium eliminates
the need for oil scraper rings. |
Pores in the plating
aid in maintaining the lube oil film. |
|
A |
The lower water
seal on a diesel engine wet cylinder liner must allow for liner axial movement.
This seal is most commonly a __________. |
neoprene O-ring |
soft copper gasket |
precision ground
flange joint |
flexible metallic
seal ring |
|
A |
Which construction
detail is apparent in the connecting rod and piston assembly shown in the
illustration? Illustration MO-0011 |
The piston is
designed with a heat dam. |
It is a fork assembly. |
The piston is
water cooled. |
The wrist pin
is free floating. |
|
D |
The illustration
shown describes a __________. Illustration MO-0069 |
four cycle opposed
cylinder diesel engine |
four cycle opposed
piston diesel engine |
two cycle opposed
cylinder diesel engine |
two cycle opposed
piston diesel engine |
|
D |
Which of the following
statements is correct concerning the connecting rod and piston assembly
shown in the illustration? Illustration MO-0011 |
The piston is
free to rotate on the carrier thrust washer. |
The piston pin
is bolted to the connecting rod. |
The piston has
a heat dam. |
All of the above. |
|
D |
Item #16 of the
piston shown in the illustration is a/an __________. Illustration MO-0011 |
oil drain passage |
bearing insert
tang |
piston carrier
pin |
thrust plate or
thrust washer |
|
B |
Piston cooling
fins are located __________. |
on top of the
piston crown |
underneath the
piston crown |
at the base of
the piston skirt |
inside the cylinder
liner cooling water jacket |
|
A |
Ring groove inserts
are occasionally used on aluminum alloy pistons to __________. |
reduce the ring
groove wear rate |
seal against crankcase
vapors |
lessen the wear
on aluminum parts of the cylinder |
allow for the
greater expansion rate of aluminum |
|
D |
Which of the following
statements would apply when checking the valve clearance of the unit shown
in the illustration? Illustration MO-0074 |
The valve is mechanically
adjusted at point "D". |
The valve is mechanically
adjusted at point "E". |
Tappet clearance
is measured between points "A" and "B". |
Cold valve clearance
is measured between components "C" and "D". |
|
D |
When inspecting
the valve mechanism shown in the illustration, normal maintenance would
include __________. Illustration MO-0074 |
mechanically adjusting
the valve at point "D" |
mechanically adjusting
the valve at point "E" |
changing the tappet
clearance as measured between points "A" and "B" |
measuring the
cold valve clearance between components "C" and "D" |
|
A |
When a naturally
aspirated four-stroke/cycle diesel engine is converted for supercharging,
which of the following changes must be made to the valve timing? |
The intake valve
opening is advanced and the exhaust valve closing is retarded. |
The intake valve
opening is unchanged and the exhaust valve closing is advanced. |
The intake valve
opening is retarded and the exhaust valve closing is advanced. |
The intake valve
closing is retarded and the exhaust valve closing is advanced. |
|
A |
When a naturally
aspirated four-stroke/cycle diesel engine is converted for supercharging,
which of the following changes must be made to the valve timing? |
The intake valve
opening is advanced and the exhaust valve closing is retarded. |
The intake valve
opening is unchanged and the exhaust valve closing is advanced. |
The intake valve
opening is retarded and the exhaust valve closing is advanced. |
The intake valve
closing is retarded and the exhaust valve closing is advanced. |
|
D |
After testing
your medium-speed engine's exhaust valve springs you find one with a spring
constant that is lower than specified by design and a length that is reduced
in length from that specified by design. What is the recommended course
of action? |
Anneal spring
to restore the spring constant to the original value. |
Restore the spring
to its original length by stretching. |
Remove shims to
restore spring to its original length. |
Replace spring
and check the valves cam and follower for marring caused by bounce. |
|
A |
During main engine
performance testing it is noticed that the firing pressure in one cylinder
is lower than the average, but cylinder compression pressure and fuel pump
delivery rate are normal. Which of the following would most likely be the
cause? |
Late fuel injection |
Worn piston rings |
Early fuel injection |
Low engine load |
|
A |
During main engine
performance testing it is noticed that the firing pressure of one cylinder
is higher than the average, but cylinder compression pressure is normal.
Which of the following would most likely be the cause? |
Early fuel injection |
Worn piston rings |
High engine load |
Late fuel injection |
|
C |
During main engine
performance testing it is noticed that one cylinder has firing and compression
pressures lower than average. Which of the following would most likely be
the cause? |
Early fuel injection |
Low engine load |
Worn piston rings |
Late fuel injection |
|
B |
A motor vessel
has three centrifuges to pre-treat the fuel which can be configured to operate
in series, parallel, and series-parallel. A large quantity of water is determined
to be present in the fuel. How would you configure the centrifuges to deal
with this problem? |
Run all three
centrifuges as purifiers and decrease throughput. |
Run two centrifuges
in parallel as purifiers discharging to the third one in series as a clarifier. |
Increase 'shoot'
cycles and run two centrifuges in series as purifiers. |
Drain settling
and service tanks more often and run two centrifuges in series, purifier
and
clarifier. |
|
D |
A motor vessel
has two centrifuges to pre-treat fuel to the engine(s) which may be
configured to operate in series or parallel. A large quantity of water has
been determined to be
present in the fuel. What actions would you take to minimize the effect
of water prior to fuel
injection? |
Run both centrifuges
in series as purifiers and increase 'shoot' cycles. |
Maintain normal
fuel oil throughput through both centrifuges functioning as clarifiers and
increase the 'shoot' cycle of the two clarifiers. |
Drain settling tank(s) and
service tank more often only, and monitor reduction in water content |
Run first centrifuge as a purifier
in series with second as clarifier and reduce throughput and
increase 'shoot' cycles'. |
|
A |
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 |
|
B |
Oil accumulating
in the exhaust piping or manifold of a diesel engine can be caused by __________. |
collapsed hydraulic
valve lifters |
worn valve guides |
excessive crankcase
vacuum |
excessive lube
oil pressure |
|
C |
When one cylinder
has a lower compression pressure and higher exhaust gas temperature than
any of the other engine cylinders, which of the conditions listed will be
indicated? |
Advanced ignition |
Clogged air intake |
Leaky exhaust
valve |
High exhaust pressure |
|
B |
Excessive wear
at part #11, as shown in the illustration, would result in __________. Illustration
MO-0027 |
improper timing |
increased oil
consumption |
lost compression |
low oil pressure |
|
A |
If a valve seat
insert, similar to that shown in the illustration is cracked, this may be
indicated by __________. Illustration MO-0043 |
white vapor in
the exhaust gas |
high exhaust pyrometer
readings on that particular cylinder |
continuous spring
surge |
a jammed indicator
cock |
|
C |
Excessively worn,
or polished ends on a diesel engine valve spring, indicate __________. |
burned exhaust
valves |
excessive spring
compression |
spring surge |
worn valve seats |
|
B |
Bouncing of the
valve gear in a diesel engine can be caused by __________. |
prolonged high
speed operation |
spring surge |
worn valve seats |
excessively tightened
spring retainers |
|
D |
What will cause
valve stem blow-by to the valve section shown in the illustration? Illustration
MO-0030 |
A cracked lower
spring plate. |
Worn, broken or
stuck compression rings. |
Damaged rubber
rings on the valve seat insert. |
Defective rubber
seal rings in the valve guides. |
|
C |
Worn diesel engine
intake valve guides can result in __________. |
increased engine
breathing efficiency |
excessive valve
lash |
excessive lube
oil consumption |
lower than normal
fuel consumption |
|
C |
Worn main bearings
will cause the compression ratio of a diesel engine to __________. |
remain the same |
increase on compression;
decrease on expansion |
decrease |
increase |
|
B |
Which of the conditions
listed could cause the cylinder relief valves on a large, low-speed, propulsion
diesel engine to lift? |
Plugged injector
nozzles |
Excessive fuel
injection |
Incorrect crankshaft
clearances |
Very late injection
timing |
|
B |
The ring lands
on a large, low-speed, main propulsion diesel engine piston may crack due
to __________. |
high main lubricating
oil system temperature |
insufficient ring
groove clearance |
insufficient cylinder
liner wear |
contaminated lubricating
oil |
|
B |
When inspecting
pistons, liners, and rings of a large two-stroke/cycle diesel engine through
the cylinder ports, a wet piston crown would indicate a __________. |
faulty oil ring |
leaky fuel injector |
faulty piston
lubricator |
broken compression
ring |
|
D |
The most practical
way of detecting an overload in one cylinder of an operating large, low-speed,
main propulsion diesel engine is to __________. |
listen for combustion
knock in that cylinder |
isolate each cylinder
and inspect the injector |
check the cylinder
exhausts for black smoke |
check the cylinder
exhaust temperature frequently |
|
B |
One method of
determining crankshaft misalignment is by __________. |
laying a straight
edge across the crank webs at the crankpin and measuring the distance to
the crankpin in two places |
taking micrometer
readings between the crank cheeks opposite the crankpin every 90° of crank
angle rotation |
measuring the
crank drop on either side of each crank throw while the crankshaft is slowly
rotated through one revolution |
rotating the crankshaft
through one revolution, pausing each 90° of rotation to measure bearing
clearances, top and bottom |
|
A |
A main propulsion
diesel engine crankshaft bearing lacking sufficient 'crush', will __________. |
tend to rotate
with the journal |
pound under load |
have a thicker
layer of Babbitt |
be lubricated
more easily than with sufficient crush |
|
D |
Which of the following
procedures should be carried out to permit the continued operation of a
crosshead engine with a leaky after cooler? |
Bypass the after
cooler to operate at sea speed. |
Switch to diesel
fuel and run at reduced speed. |
Nothing needs
to be done due to the low heating value of heavy fuel. |
Blank off the
cooling water lines and run at reduced speed. |
|
A |
While at sea,
the first engineer reports the jacket water expansion tank water has become
discolored and has a smell of exhaust on a slow speed two stroke engine.
Which would be the most likely cause? |
A cracked cylinder
liner, cylinder head or exhaust valve cage |
An open turbocharger
casing drain valve |
A leaking exhaust
manifold |
A leaking waste
heat boiler tube |
|
C |
A diesel engine
emits blue exhaust smoke as a result of __________. |
a light load |
excessive compression
pressure |
excessive cylinder
lubrication |
cold intake air |
|
b |
While inspecting
diesel engine combustion space components, which components would you consider
for particular scrutiny for evidences of high temperature corrosion? |
Exhaust valves
and seats, upper circumference of cylinder liner. |
Exhaust valves,
exhaust valve seats, piston crowns, cylinder heads and upper circumference
of cylinder liners. |
High temperature
corrosion does not effect these components. |
Undersides of
cylinder heads, piston crown and exhaust valve. |
|
D |
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 |
|
D |
Starting a large
low-speed propulsion diesel engine on diesel fuel during cold weather conditions,
will be made easier by __________. |
increasing the
quantity of starting air |
increasing the
lube oil pressure |
heating the engine
fuel supply |
heating the engine
coolant |
|
A |
Which of the routine
maintenance procedures listed is required for starting air receivers? |
Frequent draining
of accumulated moisture. |
Frequent testing
of relief valves. |
A close watch
on temperature to prevent fluctuations in pressure. |
Frequent cleaning
to remove oil and foreign matter. |
|
C |
When starting
a diesel engine at temperatures below 70°F, the frictional resistance to
turning will be __________. |
reduced by increasing
lube oil pressure |
controlled by
reducing the compression ratio |
proportional to
the lube oil viscosity |
eliminated by
heating the intake air |
|
B |
Starting air check
valves are held firmly on their seats by __________. |
cam rollers on
the camshaft |
spring force |
air pressure on
top of the valve differential piston |
air pressure on
the bottom of the valve differential piston |
|
C |
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 |
|
B |
Where is the air
charge for an air starting system stored? |
Air compressor |
Pressurized tank |
Distributor assembly |
Cylinder check
valve |
|
D |
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 |
|
D |
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 |
|
C |
Which of the listed
diesel engine starting systems is most susceptible to difficulties in cold
weather? |
Direct cylinder
admission air start |
Hydraulic |
Electric |
Air motor starting |
|
C |
Starting systems
for large, direct reversing, main propulsion diesel engines are usually
__________. |
hydraulic starting
motor |
electric starting
motor |
direct air admission |
vane type air
motors |
|
B |
Which of the following
statements is true concerning the air starting valve, labeled "III",
as shown in the illustration? Illustration MO-0046 |
During normal
engine running, the air starting valve opens and closes constantly due to
cam
action. |
The air starting
valve is opened by cam action. |
When starting
air is secured, the air starting valve is closed. |
When starting,
the air starting valve is held open by air pressure. |
|
D |
The pilot valves
in an air pilot starting system for a two-stroke/cycle, direct-reversing,
main propulsion diesel engine are operated by either a ported distributor
disc or a/an __________. |
regulator valve |
quick opening
main air valve |
pilot air start
check valve |
individual cam
for each pilot valve |
|
A |
During the starting
of a diesel engine, compression gases are prevented from backing into the
air starting system, shown in the illustration, by the __________. Illustration
MO-0046 |
cylinder air starting
check valves |
individual distribution
valves |
high pressure
in the starting air manifold |
air starting control
valve |
|
A |
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 |
|
B |
In a direct cylinder
admission air starting system, once the engine begins to fire, the air starting
check valve illustrated, is closed by __________. Illustration MO-0107 |
the starting air
pressure |
the spring force
and cylinder pressure |
a valve actuating
cam |
a pneumatic bellows
assembly |
|
C |
When an air started,
four-stroke/cycle diesel engine is being cranked over, the starting air
is admitted to each cylinder during the beginning of its __________. |
intake stroke |
compression stroke |
power stroke |
exhaust stroke |
|
D |
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 |
|
B |
Air motors used
for starting some auxiliary diesel engines are generally the type known
as a/an __________. |
accumulator motors |
vane motors |
gear motors |
plunger motors |
|
A |
Which of the following
operating characteristics of the Bendix drive friction clutch is associated
with a Bendix drive starter? |
Helps absorb the
shock when the pinion engages the flywheel ring gear. |
Disengages the
pinion from the flywheel ring gear. |
Engages the pinion
with the air start distributor. |
Prevents the pinion
starter from overrunning on the starter shaft. |
|
B |
A Bendix drive
starting motor disengages the drive gear from the flywheel by __________. |
spring force |
having the flywheel
impart a torque to the starter pinion |
rotating of the
starting cam |
applying accumulator
pressure |
|
D |
The pinion of
an auxiliary diesel electric starting motor normally engages the flywheel
ring gear by means of a/an __________. |
automatic follow-up |
magnetic type
coupling |
muff coupling
and release |
Bendix drive or
similar mechanism |
|
B |
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 |
|
B |
Auxiliary diesel
engine electric starting motors use __________. |
400 cycle per
second motor-generator power |
battery power
direct current
|
low amperage,
high voltage AC power
|
alternating current
transformers |
|
C |
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 |
lower starting
temperatures |
higher compression
pressures
|
flywheel effect |
|
B |
Which internal
combustion engine starting system uses a vane type fluid motor? |
Jet flow |
Compressed air |
Electric |
Centrifugal |
|
A |
The illustration
is of a/an __________. Illustration MO-0044 |
air driven starter
motor assembly |
power take-off
driven, vane type, air compressor |
air driven DC
generator |
battery powered,
electric motor driven vane type, hydraulic pump |
|
D |
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 |
|
A |
Which type of
starter motor is normally used in a diesel engine hydraulic starting system? |
Axial piston |
Centrifugal |
Precision gear |
Turbine drive |
|
B |
When an engine
fitted with a hydraulic starting system starts up, the starter is protected
from the higher speed of the engine by __________. |
the immediate
increase in hydraulic pressure |
the overrunning
clutch |
closing the starting
check valves |
the pivoting of
the shaft from being engaged with the flywheel |
|
A |
The purpose of
the engine-driven hydraulic pump in an auxiliary diesel engine hydraulic
starting system is to __________. |
restore hydraulic
pressure in the accumulator after starting |
engage the starter
motor with the flywheel |
fill the sump
and prevent low level in the system |
bypass the hydraulic
motor when the engine is running |
|
B |
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 |
|
A |
In a diesel engine
starting motor equipped with a Bendix drive, the pinion moves and meshes
with the flywheel ring gear due to __________. |
the shaft sleeve
spiral helix and relative rotation between pinion and starter shaft |
shifting levers
of solid mechanical linkage |
centrifugal force
developed from rotation |
electromotive
force developed at the flywheel |
|
D |
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. |
|
A |
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. |
|
D |
The component
labeled "A" on the engine reversing device shown in the illustration,
performs its function by transmitting __________. Illustration MO-0125 |
an electric voltage
which energizes solenoids to de-clutch the engine
|
a fuel oil pressure
signal which reverses the engine governor control cylinder
|
a hydraulic pressure
which shifts an alternate set of camshaft followers to ride on the engine
camshaft |
a pneumatic signal
which activates a hydraulic control cylinder allowing the camshaft to shift
axially |
|
D |
The cylinders
labeled "B" and "C" in the illustration are used to
__________. Illustration MO-0125 |
provide oil to
lubricate component "F"
o |
supply a specific
volume of oil to the engine governor |
provide the required
quantity of grease at specified maintenance intervals |
supply the force
required to shift the engine camshafts axially to reverse engine rotation |
|
B |
Intercoolers installed
on starting air compressors, reduce the possibility of __________. |
dust entering
the first stage |
lube oil carbonization |
discharge pulsations |
interstage vapor
lock |
|
D |
Which of the following
statements is true concerning the air starting valve, labeled "III",
as shown in the illustration? Illustration MO-0046 |
When starting,
the air starting valve is held open by air pressure. |
When starting
air is secured, the air starting valve is closed. |
During normal
engine running, the air starting valve opens and closes constantly due to
cam
action. |
The air starting
valve is opened by cam action. |
|
A |
During the starting
of a diesel engine, compression gases are prevented from backing into the
air starting system, shown in the illustration, by the __________. Illustration
MO-0046 |
cylinder air starting
check valves |
air starting control
valve |
individual distribution
valves |
high pressure
in the starting air manifold |
|
D |
In a direct cylinder
admission air starting system, once the engine begins to fire, the air starting
check valve illustrated, is closed by __________. Illustration MO-0107 |
a pneumatic bellows
assembly |
the starting air
pressure |
a valve actuating
cam |
the spring force
and cylinder pressure |
|
C |
In a medium-speed
marine propulsion engine equipped with direct admission air starting valves,
the cylinders without air starting valves fire first because the __________. |
fuel is admitted
only to these cylinders during cranking |
operation is under
higher compression |
cylinders are
not chilled by the expansion of the starting air |
compression is
released during starting by opening the exhaust valve |
|
D |
Which internal
combustion engine starting system uses a vane type fluid motor? |
Jet flow |
Centrifugal |
Electric |
Compressed air |
|
D |
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 |
|
B |
When an engine
fitted with a hydraulic starting system starts up, the starter is protected
from the higher speed of the engine by __________. |
the immediate
increase in hydraulic pressure |
the overrunning
clutch |
closing the starting
check valves |
the pivoting of
the shaft from being engaged with the flywheel |
|
B |
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 |
|
B |
Which of the following
operating characteristics of the Bendix drive friction clutch is associated
with a Bendix drive starter? |
Engages the pinion
with the air start distributor. |
Helps absorb the
shock when the pinion engages the flywheel ring gear. |
Disengages the
pinion from the flywheel ring gear. |
Prevents the pinion
starter from overrunning on the starter shaft. |
|
D |
The pinion of
an auxiliary diesel electric starting motor normally engages the flywheel
ring gear by means of a/an __________. |
automatic follow-up |
muff coupling
and release |
magnetic type
coupling |
Bendix drive or
similar mechanism |
|
D |
Auxiliary diesel
engine electric starting motors use __________. |
low amperage,
high voltage AC power |
alternating current
transformers |
400 cycle per
second motor-generator power |
battery power
direct current |
|
D |
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. |
|
B |
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 __________. |
piston cooling
pumps |
starting air and
fuel pumps |
exhaust valves |
All of the above. |
|
D |
The component
labeled "A" on the engine reversing device shown in the illustration,
performs its function by transmitting __________. Illustration MO-0125 |
a hydraulic pressure
which shifts an alternate set of camshaft followers to ride on the engine
camshaft |
an electric voltage
which energizes solenoids to de-clutch the engine |
a fuel oil pressure
signal which reverses the engine governor control cylinder |
a pneumatic signal
which activates a hydraulic control cylinder allowing the camshaft to shift
axially |
|
D |
The cylinders
labeled "B" and "C" in the illustration are used to
__________. Illustration MO-0125 |
supply a specific
volume of oil to the engine governor |
provide oil to
lubricate component "F" |
provide the required
quantity of grease at specified maintenance intervals |
supply the force
required to shift the engine camshafts axially to reverse engine rotation |
|
D |
Intercoolers installed
on starting air compressors, reduce the possibility of __________. |
interstage vapor
lock |
discharge pulsations |
dust entering
the first stage |
lube oil carbonization |
|
C |
You are the Chief
Engineer on a Ro/Ro vessel powered by a MAN two stroke, direct reversing,
slow speed diesel engine. While maneuvering into New York with the main
engine in Bridge control status you receive low pressure alarms on both
main air receivers. Both ship's main air compressors are operational and
running at the time of the alarms. What should you do? |
Check the air
compressors to be sure they are operating correctly. |
Take control of
the main engine in the engine control room. |
Check the air
compressors to be sure they are operating correctly. Then inform the Captain
on the Bridge that the starting air supply is not keeping up with demand
and start air pressure should be monitored closely during the reminder of
the maneuver. |
Take control of
the main engine and operate the main engine from the engine side in emergency
mode. |
|
c |
A pre-arrival
test is being performed with the engine on bridge control. The vessel has
a slow speed engine with mechanical starting air system (not electronic).
After a stop order, the engine fails to restart in the next ahead direction
order. What would be your immediate actions to restart the engine, if the
order was still ahead? |
Inform the bridge
that all are working on the problem and they may have to consider anchoring
until the problem is resolved. |
Call the bridge
and inform them of the problem. Ascertain that the main starting valve is
open and functioning properly and start trouble shooting. |
Inform the bridge.
Take engine room control of the engine, change the engine's direction to
astern position and try to restart in that position. When the engine tries
to restart, switch back to
ahead and restart. |
Call the bridge
and inform them of the problem. Ascertain that starting air tanks are up
to pressure and are lined up and start trouble shooting. |
|
D |
During maneuvering
on a slow speed diesel engine vessel, a low starting air system pressure
alarm is activated. Local starting air receivers' pressure gauges indicate
proper pressures, and compressors are running and are 'loaded' up. What
could cause the alarm? |
Malfunctioning
starting air cylinder distributor valves. |
A stuck open air
starting valve on one of the engine cylinders. |
Malfunctioning,
stuck open, main engine air starting valve. |
Faulty system
alarm pressure switch and/or a fault in the alarm circuit. |
|
C |
The starter control
valve in the hydraulic system shown in the illustration is malfunctioning.
Before removing the valve, you must first __________. Illustration MO-0049 |
drain the reservoir |
remove all plugs
from the system |
bleed off all
accumulator pressure in "E" |
ensure that the
accumulator piston is in the charged position |
|
A |
Which of the listed
items should be secured before performing any maintenance on a solenoid
operated air start valve? |
Electric power
and starting air |
Lube oil standby
pump and control air |
Hydraulic switch
and engage jacking gear |
Motor drain and
pneumatic control system power |
