- The
color of the exhaust from a diesel engine should be
A. clear
B. hazy light brown
C. hazy light blue
D. hazy light grey - In
jerk type large fuel injection pumps, pulsations are absorbed by:
A. The fuel pump resilient foundation
B. The high pressure pipes
C. The shock absorbers mounted on fuel pumps
D. The shock absorbers mounted on high pressure pipes - Which
of the following can be a possible outcome of salt water contamination in
fuel?
A. Cavitation and erosion of fuel injection components.
B. High temperature corrosion in exhaust valves and turbochargers
C. Unstable combustion
D. All of the above - The
water in a steaming auxiliary boiler should be tested daily for
A. dissolved oxygen
B. chlorides
C. sludge
D. dissolved nitrogen - What
fittings do you normally find in a main engine turbocharger prior to
compressor inlet in the air flow path ?
A. Pre-filter and diffuser
B. Pre-filter , silencer and diffuser
C. Pre-filter , silencer and inducer
D. Pre-filter , silencer vibration damper - Unit
of kinematic viscosity
A.
centipoises
B.
centistokes
C.
CCAI
D.
none of above
- Exhaust
valve seat material
A.
stainless steel,
B.
invar,
C.
nimonic
D.
income
- Drop
in compression pressure with high scavange box temp in a cylinder
A.
late injection
B.
early injection,
C.
worn
piston ring
D.
leaky exh valve
- Which
of the following statements is true?
A. The higher the viscosity index of a lubricant, the higher is the change of viscosity with temperature.
B. The higher the viscosity index of a lubricant, the lower is the change of viscosity with temperature.
C. Viscosity index is not a measure of a fluid's change in viscosity with temperature.
D. None of the above - In
case of cross scavenged engines :
A. The exhaust ports are located above the scavenge ports and they open everytime the piston reaches near TDC and near BDC
B. The exhaust ports are located below the scavenge ports and they open everytime the piston reaches near TDC and near BDC
C. The exhaust ports are located above the scavenge ports and they open every time the piston reaches near BDC
D. The exhaust ports are located below the scavenge ports and they open every time the piston reaches near BDC - While
overhauling a piston rod stuffing box, if the butt clearance of scraper
rings is found below or near the minimum, the correct remedial measure
would be ______
A. To file the ends of the rings and increase the clearance
B. To renew the ring set or fit new lamellae
C. To swap the lower rings with the upper rings
D. To renew a segment or two of ring set to obtain the desired clearance - In
a electro- hydraulic steering gear, the movement of actuator is created by
___________
A. Starting the motors on both power units
B. Operating the isolating valves
C. Starting at least one power unit and actuating the direction valves
D. Starting both power units and actuating the direction valves
1)
Friction developing between the moving parts of a governor, governor
linkage and control valve will cause the governor to
a) React with insufficient speed
droop
b)
Fail to react to small speed changes
c) Have excessive sensitivity to
small speed changes
d) Remain in the neutral position
2) A
large change in ambient temperature, or using an oil of a viscosity different
than the one recommended by the manufacturer in a mechanical hydraulic
governor, will result in the need to adjust the
a)pilot valve opening
b)
compensating needle valve
c)compensating spring tension
d)accumulator spring tension
3)
Friction, engine wear, and oil consumption in a diesel engine are
directly related to the
A) acidity of the oil
b) Pour point of the oil
c) Flash point of the oil
D)
viscosity of the oil
4) When
the prime movers of two paralleled generators, equipped with
mechanical-hydraulic governors, are operating within their designed range, the
unit with the least amount of speed drop will –
a)
pick up more of any increase in load
b)pick up less of any increase in
load
c)share an equal amount of any
increase in load
d)drop an equal amount of any decrease
in load
5)
Clearance volume scavenging in a turbocharged, four-stroke/cycle diesel
engine is accomplished
a)
during the valve overlap period
b)with only the exhaust valve open
c)at a pressure below atmospheric
d)without cooling the cylinders or pistons
6)
Trunk-type diesel engine pistons are most effectively cooled by heat
a)conducted through the engine block
b)conducted
to water cooled cylinder walls
c)conducted through the piston crown
d)losses to escaping exhaust gasses
7)
Fuel oil is injected into the cylinder of a four-stroke/cycle diesel
engine during the
a)intake stroke
b)exhaust stroke
c)power stroke
d)compression
stroke
8)
A large, low-speed, main propulsion diesel engine uses sea water to
directly cool the
a)cylinder heads
b)exhaust valves
c)scavenging
air
d)injectors
9)
The total starting air capacity required for reversible main engines is
to be sufficient for a least
a)six consecutive starts
b)eight consecutive starts
c)ten consecutive starts
d)twelve
consecutive starts
10)
The light and medium fuels utilized in internal combustion engines
provide a source of
a)lubrication for pistons and rings
b)food
for microbiological organisms
c)gases most detrimental to the
ozone layer of the atmosphere
d)all of the above
11)
Which bearing half will receive the greatest load in a two-stroke/cycle
diesel engine?
a)Lower half of the connecting rod
bearing at the crankshaft end of the rod
b)Upper half of the main bearing
c)Lower
half of the piston pin bearing in the connecting rod
d)All bearing halves share an equal
load
12)
Maximum lube system operating pressure for a diesel engine is normally
regulated by a/an
a)orifice in the pump suction
b)special filter design
c)pressure drop through the filter
d)relief
valve
13)
A naturally aspirated diesel engine at full throttle will have an intake
manifold pressure
a)slightly
less than atmospheric pressure
b)approximately equal to exhaust
manifold pressure at all times
c)that is widely fluctuating
d)constantly decreasing as engine
load increases
14)
The output pressure of a diesel engine lube oil pump is regulated by
a/an
a)relief
valve
b)metering valve
c)variable speed pump drive
d)orifice in the lube oil header
15)
An increase in the air inlet manifold pressure of a diesel engine will
result in a/an
a)decrease in maximum cylinder
pressure
b)increase in ignition lag
c)decrease
in fuel consumption per horsepower-hour
d)decrease in exhaust manifold
pressure
16)
Maximum lube oil system pressure is normally controlled by
a)the capacity of the lube oil pump
b)the speed of the lube oil pump
c)the outlet pressure of the lube
oil pump
d)a
relief valve
17)
Which of the following statements is true concerning an oil cooler?
a)The oil temperature is less than
the cooling water temperature
b)The oil pressure is less than the
cooling water pressure
c)The
oil pressure is greater than the cooling water pressure
d)The magnets are installed to
remove metal particles
18)
The highest pressure in any closed diesel engine freshwater cooling
system is at the –
a)jacket water outlet
b)expansion tank inlet
c)heat exchanger inlet
d)cooling
water pump outlet
19)
Concerning diesel propelled vessels, the astern power is to provide for
continues operation astern
a)equal to that available for ahead
operation
b)at
70 percent of the ahead rpm at rated speed
c)while underway and under all
normal conditions
d)at 70 percent of the ahead rpm of
average continuous sea speed
20)
Maintaining the lowest possible scavenging air temperature at all times
is not recommended due to the possibility of the
a)air charge density becoming too
high
b)piston crown surfaces becoming too
cold
c)formation
of excessive quantities of condensate
d)compression pressure being greatly
reduced
21) The
nuts of main bearings, connecting rod bolts and all other moving parts are to
be secured by
a)hardened steel nut locks
b)cotter pins made of spring steel
c)split
pins or other effective means
d)hydraulic nuts as commonly found
on large low speed engines
22) If
the valve tappets in a diesel engine are set at greater clearances than those
specified by the engine manufacturer, those valves will
a)open
late and close early
b)open late and close late
c)fail to open when the engine is
cold
d)fail to open at normal operating
temperature
23)
Proper lubrication of the main bearings is more easily obtained in a
single acting four-stroke/cycle diesel engine than a single acting
two-stroke/cycle diesel engine because
a)bearing
pressure in a four-stroke/cycle single acting diesel engine is continually
reversed
b)bearing pressure in a
two-stroke/cycle single acting diesel engine is continually reversed
c)the maximum bearing pressure is
higher in a single acting two-stroke/cycle diesel engine
d)two-stroke/cycle diesel engines
require more complicated lubrication piping
24)
Increasing the valve clearance between a valve stem and rocker arm, will
result in the valve
a)closing later
b)opening sooner
c)staying
open for a shorter period of time
d)staying open for a longer period
of time
25)
Which of the following conditions can cause above normal air temperature
to develop in the intake manifold of a four-stroke/cycle, turbocharged, diesel
engine?
a)Clogged air intake filters
b)Piston blow-by
c)A
defective after cooler
d)Faulty exhaust valves
26)
Cooling the intake air supplied to a diesel engine will
a)reduce mean effective pressure
b)decrease average compression
pressure
c)decrease air charge density
d)increase
power output
27)
Which of the following condition may need to be reduced when operating a
large, low-speed, main propulsion, diesel engine at low loads?-
a)Injection pressures
b)Control air supply pressure
c)Cooling
water flow through after coolers
d)Lube oil temperature
28)
One function of the fuel pump delivery check valve is to
a)prevent carbon deposits from
forming on the injector nozzle
b)help
the injector needle reseat without dribbling at the nozzle holes
c)provide a prolonged pressure drop
in the high pressure steel piping to the injector
d)ensure a fuel leakoff between the
plunger and barrel which provides lubrication for relative movement
29) A
closed freshwater cooling system is commonly used with marine diesel engines
because the –
a)need for water treatment is
eliminated
b)cooling water temperature
differential is greater
c)cooling water pumps are directly
reversible
d)jacket
water temperature is more easily controlled
30)
Fuel droplets injected into a diesel engine cylinder must have adequate
penetration to
a)prolong the ignition delay period
b)ensure the beginning of fuel
injection
c)thoroughly
utilize the air charge
d)allow controlled fuel combustion
31)
The valve cam slope angle determines the –
a)engine torque characteristics
b)acceleration
rate of valve opening and closing
c)engine fuel efficiency
d)diameter of intake and exhaust
valves
32)
The rate of fuel injection in a diesel engine cylinder depends primarily
on
a)the
size of the holes in the fuel nozzle
b)timing of the pump
c)supply pressure to the pump
d)shape of the combustion chamber
33)
Which of the following devices is normally provided to prevent oil
starvation in a diesel lubrication system utilizing the "full flow"
principle?
a)Duplex strainer
b)Three-way valve
c)Pressure
relief bypass line around the filter
d)Mechanical straining filter
34)
A port-and-helix fuel injection pump having upper and lower plunger
helixes is designed to
a)vary fuel delivery and return
pressure
b)vary
the beginning and ending of injection
c)operate with residual fuels only
d)provide maximum fuel delivery rate
35)
One advantage of hydraulic clutches over mechanical clutches in diesel
engine installations is –
a)the power is transmitted at very
high efficiency of 60%
b)the torsional vibrations are
transmitted directly to the reduction gears
c)each clutch has a separate oil
gland for reverse operation
d)no
mechanical connection exists between the driving and driven elements
36) An
individual injection pump is designed for variable beginning and constant
ending of injection. For diesel engines operating at constant speeds, the start
of injection will
a)advance
as the load increases
b)retard as the load increases
c)remain unchanged regardless of
load
d)always occur at top dead center
37)
The amount of fuel injected in a particular time, or degree, of
crankshaft rotation is termed
a)metering
b)timing
c)rate
of injection
d)rate of distribution
38) In
a normally operating diesel engine, the main source of lubricating oil
contamination in the crankcase is a result of the –
a) metal particles loosened by wear
b)air when no air cleaners are used
c)condensation of water wapors
d)breakdown
of the lubricating oil by dilution
39)
On small diesel engines, a noticeable decrease in the time interval
between the replacement of the lube filter cartridge indicates –
a)piston
ring blow-by
b)dirty air filter
c)excessive oil pressure
d)excessive oil temperature
40)
When the lower edge of the spiral begins to uncover the release port in
a jerk pump, the
a)pumping continues until the
plunger travels its full stroke
b)effective
pumping stroke of the plunger ends
c)pres. drops slowly until the full
stroke is attained
d)plunger rotates to the zero
delivery position until next stroke
41)
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 –
a)increased blow-by in all cylinders
b)incomplete combustion in all
cylinders
c)overloading
in all cylinders
d)insufficient fuel delivery to all
cylinders
42)
Proper operation of the main engine reduction gear set requires the
operator to monitor
a)the sump oil level
b)oil flow sight glasses
c)bearing temperatures
d)all
of the above
43)
The duration of fuel injection developed by an individual port-and-helix
fuel injection pump, is determined by the –
a)total pump stroke
b)pump plunger diameter
c)plunger helix angle
d)effective
pump stroke
44)
Before starting a diesel engine using an attached lube oil pump, the
engineer should
a)open the bypass line
b)cut in the lube oil cooler
c)pressurize
the lube oil system
d)top off the expansion tank
45)
A diesel engine using lube oil with too high a viscosity will exhibit
a)increased
starting difficulty in cold weather
b)increased oil consumption
c)thickening at higher operating
temperatures
d)minimal friction losses
46)
If the main propulsion diesel engine governor works irregularly with a
jerking motion, a possible cause can be-
a)a
sticking fuel control linkage
b)a malfunctioning overload cam
c)an unlocked overspeed trip
d)floating valves
47)
During extremely cold weather, while starting an engine, it turns too
slowly and fails to start. This problem is most likely the result of
A) High fuel oil viscosity
b) Low fuel oil temperature
c)
High lube oil viscosity
d) Energized glow plugs
48)
Prolonged operation of a diesel engine with a closed cooling water
system, at lower than normal designed temperatures can –
a)increase power output
b)decrease lube oil viscosity
c)eliminate fuel knock
d)cause
sulfuric acid formation
49)
Which of the listed governor characteristics will greatly affect the
load sharing relationship between paralleled diesel generators?-
a)Sensitivity
b)Power
c)Speed
droop
d)Compensation
50) An
emergency diesel generator cooling system is equipped with an automotive type
thermostat. If the thermostat bellows loses its charge, the thermostat will
a)open, and the coolant temperature
will increase
b)open, and the coolant temperature
will decrease
c)close,
and the engine coolant temperature will increase
d)close, and the coolant temperature
will decrease
51)
Fuel oil penetration into the cylinder of a diesel engine is
a)dependent on air turbulence
b)reduced
by finer atomization
c)increased by finer atomization
d)non-existent in the pre combustion chamber system
52)
Pre combustion chambers, air cells, and energy cells in high-speed,
small bore diesel engines all serve to increase-
a) firing pressure
b) Ignition quality of fuel
c) fuel-air ratio during compression
d)
Turbulence
53).
Which of the following statements best describes the operational
characteristics of an isochronous governors?-
a)they are suitable for use on main
propulsion units
b)they
strive to maintain a constant engine speed for all values of steady load
c)they cause a proportional drop in
engine speed as the load is increased
d)they have poor sensitivity at high
RPM.
54). Theoretical perfect combustion in a diesel engine
yields by-products of
a)aldehydes and carbon dioxide
b)water vapour and carbon monoxide
c)nitrogen and carbon monoxide
d)water
vapour and carbon dioxide
55)
Combustion knock can occur in the cylinders of a diesel engine under any
condition permitting-
a)a shortened ignition delay period
b)a lean fuel/air mixture
c)excess
fuel in the combustion chamber
d)rapid vaporisation of injected
fuel droplets
56)
When exessive fuel dilution is noted in the lube oil, the oil should be-
a)centrifuged`
b)filtered
c)strained
d)changed
57) Sticking of diesel engine piston
compression rings may be caused by-
a)high compression pressure
b)excessive ring action
c)excessive
cylinder lubrication
d)improper ring rotation
58)
When fuel is injected late into a diesel engine cylinder,
a)the exhaust will be clear
b)fuel consumption will be low
c)all the fuel will be burned at top
dead center
d)fuel
consumption will be high
59) ME LO inlet temperature should
be—
a)40C
b)50C
c)60C
d)55C
60) Exhaust temp of one ME cylinder
high could mean
a)fuel valves need overhaul
b)exh valve leakage
c)piston ring blow past
d)all
of above
61)For a 2 stroke engine with
exhaust ports—
a)scavenge ports close
before exhaust ports
b)exhaust ports close before
scavenge ports
c)scavenge ports and exhaust ports
close at same time before BDC
d)scavenge ports and exhaust ports
close at same time after BDC
62)For a 2 stroke engine with
exhaust valves—
a) Scavenge valve closes before
exhaust ports
b) Exhaust valves close
before scavenge valves
c) Scavenge and exhaust valves close
at same time before BDC
d) Scavenge and exhaust valves close at same
time after BDC
63) The maximum amount of liner wear
occurs at—
a)top of liner
b)1/
3 downward from top centre
c)midway
d)bottom of liner
64) Which of the following cannot be
removed from fuel oil by centrifuging in the purifier and micro-filtration
a)sodium
b)aluminium and silicon
c)vanadium
d)ash
65)In the preheater before purifier
the recommended heavy oil preheat is-
a)85C
b)98C
c)110C
d)120c
66)For a ME which has a 5 micron
fuel filter, a homogenizer ( omega fire ) is usually fitted –
a)before the purifier
b)after the purifier
c)after the 5 micron filter to ME
d)before the horizontal clarifier
67)For a main engine fuel system
which has a 5 micron filter ,a super decanter is usually fitted—
a)before the purifier
b)after the purifier
c)after the 5 micron filter to ME
d)before the horizontal clarifier
68)For low sulphur 380 cst fuels the
TBN of MECC oil should be in the region of—
a)20
b)40
c)60
d)70
69)Using a MECC oil of high TBN can
cause—
a)improper centrifuging of water
b)Calcium laquer deposits on
bearings
c)sludge formation with water in ME
sump
d)all
of above
70)When using a high TBN MECYL oil
and suddenly the ship has to use low sulphur 380 cst HO in the ME, due to SECA
area entry—
a)reduce
the feed of MECYL
b)increase the feed of MECYL
c)do not change the feed rate
d)increase the TBN of the MECYL
71)ME scavenge air temperature is
adjusted by-
a)controlling the sea water inlet
b)controlling
the sea water outlet
c)keeping outlet valve 100% open
always.
d)none of above
72)The ME jacket FW cooling outlet
temperature is-
a)80C
b)95C
c)50C
d)55C
73)The scavenge air high temperature
set point for 2 stroke ME is
a)40C
b)55C
c)65C
d)35C
74) You see white smoke coming from
the ME funnel stack, this could be
a)one or more cylinders not getting
enough fuel
b)too low compression pressure
c)water
in fuel
d)all of above
75)The crank angles of a 2 stroke
engine are—
a)2 cylinder engine/ 90 degrees
b)4 cylinder engine/ 60 degrees
c)6 cylinder engine/ 90 degrees
d)4
cylinder engine/ 90 degrees
76)Crankcase explosions of main
engines can be due to-
a)over heating of MECC oil
b)poor condition of liners/ rings
c)crankshaft / thrust bearing
failure
d)
all of above
77)If there is air in the fuel oil
filter, the compression and re expansion of air will—
a)not allow the fuel injection valve
to close
b)not
allow the fuel injection valve to open
c)makes no difference
d)none of the above
78)
Which of the bearings listed are most widely used for the main and
connected rod bearings of a diesel engine?
a)roller
b)sleeve
c)precision
insert
d)needle
79)
Which of the following methods is normally used to lubricate bearings in
a small high-speed diesel engine?
a)splash lubrication
b)pressure
lubrication
c)sight feed lubricators
d)mechanical lubricators
80) In
a naturally aspirated diesel engine, the volume of air intake is directly
related to engine
a)compression ratio
b)valve
size
c)fuel pressure
d)cylinder clearance volume
81) In
a bypass filtering system for a medium or high speed diesel engine, the lube
oil bypassing the filter
a)returns directly to the suction
side of the pump
b)returns directly to the sump
c)flows
to the engine bearings
d)flows through a second-stage
strainer, reheater, and returns to the sump
82) In
a diesel engine, the main bearings are used between the
a)connecting rod and the crankshaft
b)wrist pin and the connecting rod
c)camshaft and the engine block
d)crankshaft
and the engine block
83)
Heat exchangers are most commonly found in a small auxiliary diesel
engine
a)fuel oil system
b)governing system
c)air starting system
d)lube
oil system
84)
Multiple concentric valve springs are often used with diesel engine
valves to
a)enable research and development of
cam contour to be simplified
b)operate
the valve gear where the larger force is required, but space limitations
restrict use of a large spring
c)allow for easier valve replacement
d)enable a total smaller valve
spring force to keep the valve tight on its seat
85)
Which of the listed bearing installations is subjected to swinging
motion?
a)crankshaft journal
b)crankpin bearings
c)wrist
pin bearings
d)thrust bearings
86)
One advantage of vacuum feed type cylinder lubricators over the liquid
sight type is-
a)there are fewer moving parts
b)adjustment is not required
c)better
metering accuracy
d)a lower grade of oil may be used
87)
Cooling water pumps driven by direct reversing diesel engines are
usually of the straight impeller vane type -pump with a concentric
housing to
a)provide
cooling water flow when the engine is running either ahead or aster
b)provide the greatest pump
efficiency
c)prevent pump clogging from marine
growth
d)prevent cavitation at the pump
outlet
88)
Motor vessels usually have an independent lube oil system each for the
main engine and main reduction gears because
a)coolers are not needed for the
gear system
b)contaminants
produced by the engine could harm the reduction gears
c)non additive oils are used in the
main engine system
d)different type centrifuges are
required for the main engine and reduction gear lube systems
89)
Which of the bearings listed is most widely used for main and connecting
rod bearings of modern diesel engines?
a)Steel-lined
b)Poured babbitt, self-aligning
c)Split roller
d)Precision
insert
90)
Directional intake ports in diesel engines are used to
a)reduce air charge turbulence
b)induce
air swirl
c)deflect hot combustion gas away
from the valves
d)oppose the effects of piston
induced squish
91)
Diesel engine main and connecting rod precision bearings are made in
halves. Each half exceeds one-half the bearing circumference by a small amount.
The small amount is termed
a)clearance
b)crush
c)pitch
d)thrust
92)
The piston rod scraper box incorporated in a single acting
two-stroke/cycle, crosshead diesel engine serves to
a)eliminate the necessity for an oil
scraper ring
b)prevent side thrust and cylinder
scoring
c)prevent
sludge and dirty oil from entering the crankcase
d)scrape oil and carbon deposits off
the cylinder walls
93)
The proper location for journal bearing oil grooves is
a)in the region of the load bearing
surface
b)as
a side relief where the two shells meet
c)at the bottom of the bearing
d)halfway between bottom and where
shells meet
94)
How are hydraulic valve lash adjusters on diesel engine rocker arm
assemblies lubricated?
a)Cup-fed grease
b)Sealed self-lubricators
c)Metered hydraulic oil supply
d)Forced
lube oil supply
95)
Main propulsion diesel engines having a bore exceeding 300 mm are to
have at least
a)two independent means of starting
the engine
b)five air starting valves to permit
the admission of starting air at any crank angle
c)one
(explosion relief) valve at the position of each main crank throw
d)two engine driven lube oil pumps
capable of parallel operation
96)
Integral water jacket liners use O-rings near the bottom of the liner,
these O-rings serve to
a)form a water seal between the
liner and engine block
b)allow for slight misalignment of
the liner
c)prevent
the escape of lubricating oil from the crankcase
d)ensure proper temperature flow
between the liner and engine block
97)
Telescopic pipes to the piston of a large slow-speed main propulsion
diesel engine are designed to prevent
a)excessive crankcase pressure
b)excessive lube oil temperature
c)contamination
of the lube oil by water
d)contamination of the cooling water
by lube oil
98)
A characteristic of a bearing material which permits small dirt
particles to become embedded in the surface &is
a)desirable,
as it will prevent damage to the journal surface
b)desirable, as it will assist in
keeping the lube oil filters clean
c)undesirable, since the embedded
particles will score the journal
d)undesirable, since the particles
will interfere with lube oil flow
99)
Most fuel injection nozzles are opened by
a)fuel
oil pressure
b)a cam operated follower
c)a spring-loaded pressure plate
d)timing gears keyed to the
crankshaft
100) Which of the following devices controls the
discharge flow rate of an attached, positive displacement, rotary gear, diesel
engine, lube oil pump?
a)A pressure regulating valve
b)A pressure relief valve
c)The
engine speed
d)An orifice
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