25 years ago my ship encountered very bad weather in the Mediterranean sea.
So as soon as my ship berthed at an Italian port Livorno, I had to go ashore to NOTE PROTEST.
In Italy, there is no notary public. So the captain has to go to the court , raise his hand and swear JURO-- and say whatever he wants to the judge.
There I noticed a British First Engineer in bad shape, literally he was frightened. So I asked him " May be if you can tell me your problem, I can help you out ".
He said in the same bad weather his ship's main engines failed and in the process of inspection his Chief Engineer got CRUSHED TO DEATH inside the crank case.
I asked him " Who else was there inside the main engine crank case with your Chief Engineer? This is to prove that you did NOT push him and murder him"
The poor guy clutched his head , literally got his head in a spin and sat on the floor.
Then he said " I was the only guy with him, there were NO witnesses!"
Then I asked him " Did your Chief Engineer engage the TURNING GEAR before he entered the crank case "
He looked puzzled
I said " This is to prevent the crankshaft from sudden spin when a wave hits the ship's propeller in rough seas . Cheer up buddy - you cannot be charged for murder "
Just an example --how a little knowledge is a dangerous thing.
Nowadays we have ship's engineers getting promoted very fast, by "nice nellies" who give more importance to THREE BAGS FULL of SIRS , than to merit.
If you are an engineer at sea find out what you are worth!
At sea you are only respected for what you are worth! A donkey on a throne is still a donkey!!
Correct- plus two marks
Wrong - minus one marks
Did not attempt- minus two marks
Time allowed- 90 minutes
If you score less than 20% marks -- you are NOT an engineer.
The lack of engineering awareness at sea in amazing. People keeping doing cures , with NO dang idea of prevention.
We keep talking about bust AE conrods, how to tighten the bolts etc-- without even understanding that this piece of metal is supposed to PUSH and not to PULL.
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
8) A large, low-speed, main propulsion diesel engine uses sea water to directly cool the
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
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
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 continiuos 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 continious 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
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
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?
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?
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
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 itself
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)pressure drops slowly until the full stroke is attained
d)plunger rotates to the zero delivery position until the 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
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
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?
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 precombustion chamber system
52) Precombustion chambers, air cells, and energy cells in high-speed, small bore diesel engines all serve to increase
b)ignition quality of fuel
c)fuel-air ratio during compression
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
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—
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
d)bottom of liner
64)Which of the following cannot be removed from fuel oil by centrifuging in the purifier and micro-filtration
b)aluminium and silicon
65)In the preheater before purifier the recommended heavy oil preheat is-
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—
69)Using a MECC oil of high BN 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 BN 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 BN 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-
73)The scavenge air high temperature set point for 2 stroke ME is
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 reexpansion 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?
79) Which of the following methods is normally used to lubricate bearings in a small high-speed diesel engine?
c)sight feed lubricators
80) In a naturally aspirated diesel engine, the volume of air intake is directly related to engine
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
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?
c)wrist pin 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 astern
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?
b)Poured babbitt, self-aligning
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
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?
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 and 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
101) The expansion tank for a diesel engine closed cooling system is designed to maintain a constant head on the system and
a)reduce water temperature
b)reduce water turbulence
c)provide an air cushion
d)allow for an increase in water volume as the engine warms up
102) To minimize corrosion, fuel oil strainer disks, spacers and scraper blades are made of
d)monel metal or stainless steel
103) Which of the following statements describes the function of an expansion tank in a diesel engine cooling system?
a)Maintains a constant head on the system
b)Reduces the air cock when fires are lighted
c)Provides a low pressure point for the addition of makeup cooling water
d)All of the above
104) On a large diesel engine installation, crankshaft axial alignment is maintained by the
a)piston rod guides
b)engine thrust bearing
d)main shaft flexible coupling
105) Scavenging in a four-stroke/cycle diesel engine occurs during the
a)last part of the exhaust stroke, and the first part of the intake stroke
b)last part of the intake stroke only
c)early part of the injection stroke only
d)early part of the power stroke
106) In a large, slow-speed, main propulsion diesel engine, which of the parts listed is under tension when the engine is running?
107) The lube oil cooler is located after the lube oil filter in order for
a)the filter to operate more efficiently
b)the lube oil cooler to be bypassed
c)positive lube oil pump suction to be assured
d)galvanic action in the cooler to be minimized
108) In two-stroke/cycle diesel engine, the process of scavenging begins as the
a)piston nears and passes TDC
b)early part of the upstroke
c)piston passes BDC
d)early part of the downstroke
109) With respect to the flow of lubricating oil through a diesel engine, the lube oil coolers are located after filters in order to
a)allow filtration of less viscous oil
b)decrease the pressure drop across the filter
c)improve overall filtration
d)all of the above
110) Passages are drilled in the crankshafts of diesel engines to provide lubricating oil to the
b)connecting rod bearings
c)piston pin bushings
d)All of the above
111) The outlet from an expansion tank of a closed freshwater cooling system should be piped to the
a)cylinder head water outlet header
b)cylinder jacket inlet main
c)heat exchanger inlet connection
d)jacket water pump suction line
112) The intake valves in diesel engine are reseated by
113) Small amounts of moisture are necessary to trigger the growth of microbiological organisms found in some marine fuels. Some sources of water contamination are
a)tank surface leakage
b)humidity and condensation
c)improper tank washing procedures
d)All of the above
114) The main function of tie rods in the construction of large, low speed diesel engines is to
a)stiffen the bedplate in way of the main bearings to increase the engine`s longitudinal strength
b)accept most of the tensile loading that results from the firing forces developed during operation
c)mount the engine frame securely to the hull to prevent shaft coupling misalignment
d)connect the crosshead solidly to the piston rod
115) On most modern diesel engines,the main and connecting rod bearings receive their lubricating oil by
116) A unit type fuel injector is used on a diesel engine to
a)meter the fuel
b)produce the proper fuel oil pressure
c)atomize the fuel
d)all of the above
117) Lubricating system for diesel engines are usually designed to initially provide lube oil to the engine
118) Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are
a)operated manually once each hour
b)operated until the engine has started
c)placed into operation only at maximum load
d)adjustable to meet lubrication requirements
119) Shacker, circulation, and spray are the three general methods used in
a)pre-injection fuel oil treatment
b)lube oil filtration
c)fuel oil purification
120) Fuel injector nozzles are usually of the multi-orifice type with the number and placement of the holes arranged according to the
a)type of piston rings
b)pressure of the fuel system
c)size of the pump plunger spring
d)design of the combustion chamber
121) What is the crank angle between any two crank throws in the firing order of a four-stroke/cycle, in line, eight cylinder diesel engine?
122) The main reason counterweights are added to crankshafts is to
a)reduce piston side thrust
b)reduce crankshaft end thrust
c)provide uniform loading and wear of main bearings
d)increase the strength of the crank webs
123) A viscous damper, as used on a marine diesel, is a sealed precision built device which dampens the torsional vibrations in the
124) A crankshaft whose center of gravity coincides with its center line is said to be
125) The possibility of damage from operating a diesel engine at critical speeds is reduced by the use of
a)an isochronous governor
b)elastic engine mounts
c)a vibration damper
d)a cast iron bed plate with good flexible qualities
126). In a diesel engine lube oil system, which of the following parts should be lubricated first?
127) When fuel oil heaters are required for engine operation,
a)each heater shall have the capacity to supply the main engine at full power
b)at least two heaters of approximately equal size are to be installed
c)the system shall be designed to permit series or parallel operation
d)none of the above
128) An advantage of aluminium pistons compared to cast iron pistons is:
a)greater high temperature strength
b)better heat conductivity
c)greater weight per cubic cm
d)increased resistance to wear
129) Which engine component increases air density and helps to improve engine operating efficiency?
130) An electric heater built into the cylinder water jacket would be used to
a)raise lube oil viscosity for easier starting in cold weather
b)increase air inlet temperature
c)increase compression ratio
d)increase water temperature for easier starting in cold weather
131) Which is found with both mechanical and hydraulic governors?
a)direct linkage between the ball head and fuel rack
c)a compensating device
132) Which of the following design features will reduce the possibility of overheating the top compression rings of a cast iron piston?
a)The top ring is located as close to the piston as possible
b)The inside surface of the piston head is rounded into the ring belt
c)A nickel-bearing insert is cast into the top ring groove
d)A heat dam design is sometimes used in the piston head
133) The purpose of heat dam used in some diesel engine cast iron pistons is to
a)concentrate all heat in the piston crown
b)increase the distance of travel for heat from the crown to the top ring groove
c)ensure that all heat in the piston crowns is conducted to the top ring
d)provide a short direct path for heat to flow from the crown to the top ring
134) Valves used in diesel engine fuel oil pressure piping are to be
a)installed to close against flow
b)solenoid released upon the failure of engine lubrication
c)either of the gate or globe valve type
d)forge constructed under the approval of the Marine Inspector
135). Cast iron pistons used in large propulsion engines are constructed with
a)no taper whatsoever
b)the skirt being tapered and smaller than the crown
c)the skirt being tapered and larger than the crown
d)the crown being tapered and smaller than the skirt
136) The diameter of a piston is usually less at the crown than at the skirt, in order to
a)facilitate the installation of piston rings
b)allow for the expansion of the piston during operation
c)prevent crankcase vapors from entering the combustion chamber
d)reduce wearing of the upper cylinder liner
137). Which of the following manufacturing methods is recommended for diesel engine fuel injection line piping?
b)Electric resistance welded
138) Exhaust pipes of multiple engine installations are not to be interconnected, but are to be run separately to the atmosphere
a)unless arranged to prevent the return of gases to an idle engine
b)to a point not lower than the highest load line
c)at a location segregated from other ventilation systems
d)and shall be protected by a rain guard or similar device
139) Which of the bearing types listed is most commonly used in smaller vessel main propulsion reduction gears as thrust bearings?
d)tapered roller bearings
140) The main reason for using bimetallic piston rings is to
a)increase engine thermal efficiency
b)reduce specific fuel consumption
c)reduce the probability of ring fracture
d)allow for ring expansion
141) A spring-loaded centrifugal flyweight governor responds to reduced engine load with an immediate increase in
a)pilot valve oil pressure
b)speeder spring force
c)compensation needle valve clearance
d)centrifugal force on the flyweights
142) The reason why the pneumatic reversible roller guide of fuel pump could oscillate is
a)incorrect clearance in the air cylinder guideway/ reverse arm bushing
b)too large air pressure drop
c)insufficient air supply
d)all of above
143) Reasons for exhaust valve hammering could be-
a)deficiency in oil supply
b)errors in air spring
c)excessive leakage in the HP oil system
d)all of above
144) error in the air spring system causing exhaust valve hammer can be due to—
a)air pressure too high
b)maladjusted safety/ drain valve
c)supply pressure not corresponding with safety valve opening pressure
d)all of above
145)deficiency in oil supply causing exhaust valve hammering can be due to-
a)foaming oil due to air leak at pump suction
b)too low oil supply pressure
c)too high oil temperature (MECC ) causing low viscocity
d)all of above
146) excessive difference between combustion pressure and compression pressure in a ME cylinder can be due to
a)low scavenge air pressure
b)change in exhaust valve timing
c)burnt exhaust valves
d)all of above
147)the difference between water washing and dry cleaning the TC turbine is
a)there is no difference one is wet, the other is dry
b)wet washing requires reduced load
c)dry cleaning requires reduced load
d)none of the above
148) oscillations of pneumatic reversible roller guide for fuel pump can cause-
a)mechanical damage to air cylinder
b)leakages on manoevering air
c)loss of engine manoeveribility
d)all of above
149) During manoevering the MECYL feed rate is usually
a)125% of service feed rate
150)The difference between the max combustion pressure and compression pressure in a 2 stroke engine cylinder unit is
151) The air spring pressure to prevent ME exhaust valve hammer is in the region of—
152.Your indicator diagram from one of the main engine cylinders is shown. P Comp normal, P Max is low--What kind of steps do you think is necessary to rectify the failure?
A Check fuel injector valve, fuel injection timing, fuel pump suction valve and fuel pump lead
B Clean air cooler and turbocharger air cooler
C Adjust fuel pump lead only during operation
D Increase fuel pump setting.
153.Your indicator diagram is as shown. What kind of steps do you think are necessary to rectify the failure? Pc normal pm high
A Check if fuel injection is too early or fuel pump lead too large
B Check if fuel injection valve is correctly by adjusted.
C Check that you have correctly viscosity/fuel preheating.
D Replace the fuel valve.
154.A drawn indicator diagram from one of the main engine cylinders is as shown. What kind of steps are necessary to rectify the failure?—pc and pm both low
A Overhaul the unit to determine faults such as: piston ring blow-by, exhaust valve malfunction, clogged scavenging ports, delayed ignition etc.
B Adjust fuel pump lead to inject more fuel so as to maintain power balance
C Change fuel injection valve
D Check fuel pump safety valve.
155.During inspection of piston and liners through scavenging ports, piston rings on all units were found as shown (micro seizure). The best way to stop its progress is:
A Increase cylinder oil consumption, determine fuel quality and readjust the fuel oil purifiers
B Increase cylinder oil consumption
C Replace all piston rings
D Run engine at lower load.
156.During inspection and calibration of one unit, you observe the situation shown. The conclusion is clover leafing. The main engine uses high grade TBN cylinder oil. What do you have to do in order to reduce wear?—depression on either side of all lub orifices—like 10 paise coin
A Decrease jacket cooling water temperature to avoid heat stress
B Increase the jacket cooling water temperature to avoid the sulphur dew point
C Increase cylinder oil consumption to neutralize the sulphur
D Contact engine maker for advice.
157.Your vessel is entering a tropical area and high humidity is expected. To avoid condensation in the main engine's air cooler, it is recommended to:
A Operate the engine with slightly open drain cocks, scavenging to get rid of the water
B Reduce speed.
C Decrease the air temperature so proper draining can be achieved from the air cooler
D Increase scavenging air temperature to above dew point
158.During inspection of the crank bearing for one of the units in the main engine, the bearing shell was found as follows: Surface of the white metal was black and very hard. Patches of black incrustations have worn grooves in the journal. What was the cause?
A Dirt in the lubricating oil
B Wrong casting of bearing shell
C Water in the lubricating oil during service
D Bearing shell service time exceeded.
159.When carrying out piston overhaul, it is important to clean the ring grooves properly. Why?
A To make sure gas pressure can enter freely on top of and behind the piston ring
B To make the rings fit in the groove
C All rings must be changed to maintain a perfect sealing
D That piston rings can move freely in the grooves.
160.During operation of the main engine, the exhaust temperature increases on one of the cylinders. The turbocharger starts surging and smoke from the turbocharger inlet air filter occurs. What is the probable cause?
A High back pressure in the exhaust system
B Turbocharger failure
C Fuel valve stick in open position.
D Scavenge box fire
161.You are having a blow-by on the main engine, but due to the circumstances, it is impossible to stop and do a piston overhaul. What is the correct action to take?
A Reduce speed.
B No action necessary.
C Reduce speed temporarily and increase cylinder oil consumption.
D Increase cylinder oil consumption.
162.You have installed a new bearing in the main engine. What is the necessary action to take in the running-in period?
A Stop after 30 min. running to hand feel the bearing.
B Allowance must be made for a running-in period with reduced speed and careful temperature monitoring.
C No necessary steps to be taken.
D Allow for 1 hr. running with appropriate temperature monitoring of the bearing.
163.You are experiencing large hunting on the fresh water cooling system. What is the reason?
A The fresh water circulating pump is worn out.
B The cooling water temperature is too low.
C You have a cracked liner, or cover.
D The expansion tank is empty.
164.Why is it important to check the timing on the cylinder oil lubricators?
A To avoid high temperature in the combustion chamber.
B To get the right amount of oil into the cylinder.
C To get the oil into the cylinder when the piston is in the right position
D To avoid excess lubrication.
165.Why do we use cylinder oil?
A To neutralize the sulphur and get a lubricating oil film between piston rings and liner.
B To get a lubricating oil film between piston rings and liner.
C To neutralize the sulphur in the fuel.
D To avoid blowby.
166.How large a deviation in opening pressure can be accepted in a diesel engine injection valve?
A 15 kg/cm2
B 40 kg
C 50 kg
D 70 kg
167.What will the effect be, if you have a fuel injector valve that is dripping after the injection is finished ?
A Less carbonizing.
B Damage to piston and liner.
C Greater output of the engine.
D Better combustion.
168.How is the quantity of fuel oil, in HP fuel oil pump adjusted when the engine is running ?
A By adjustment of the pressure valve in the pump.
B By adjusting the length of the pump stroke.
C Turning the plunger piston according to engine load
D Adjusting oil flow to the HP fuel oil pump.
169.When a changeover from HFO to diesel oil is going to take place, we want this to be carried out as follows
A as fast as possible to save HFO.
B as fast as possible to save steam.
C as quick as possible, to obtain a fast temperature reduction to cool the HP fuelpumps.
D slow to get slow cooling.
170.If you are going to enter the engines crankcase (go inside), how will you secure the engine after you have closed the main starting air valve ?
A Engage the turning gear on the engine.
B Close absolutely all valves on the starting air bottle.
C Close the instrument air supply.
D Keep a man posted in the control room to watch that nobody tries to start the engine
171.If you get a heavy scavenging air fire, which one of the following part is likely to take the most serious damage ?
A Stuffing box.
B Exhaust valve.
D Crosshead bearing.
172.Why are we blowing the engine before start (slow turning on air) ?
A To be sure that we do not have water collected in the cylinders.
B To be sure that no parts are loose, or that the engine is blocked from rotation.
C To get fresh air into cylinders ensuring a safe start of the engine.
D To be sure that all indicator cocks are closed, and no passage into the combustion chamber.
173.The cylinder oil for FO with high sulphur content is supposed to be:
D does not matter.
174.A 2 stroke engine is usually equipped with an auxiliary blower fan, which is supposed to be used:
A continuously, together with the turbochargers to ensure enough air to the engine during full speed running.
B during continuously reduced speed under a longer sea voyage.
C during manoeuvre and manoeuvre speed condition (arrival and departure)
D during a scavenging fire, to help put out the fire.
175.What do you consider as the most important task after a piston job ?
A A search inside the crankcase for tools and rags.
B Starting the auxillary blower to ventilate the scavenging belt, and the cylinder liners, to ensure that the engine has sufficient fresh air for starting.
C Patch up destroyed paint work on the crankcase doors.
D Starting the engine to see that it rotates
176.Why is it so important to keep the lub oil viscosity within safe limits?
A To keep the oil protective film between moving metal surfaces .
B The luboil viscosity has no influence on the oil's lubrication ability.
C To keep the additives in good condition.
D It is not important
177.Total Base Number ( TBN ) is important as a measure of neutralizing ability against strong Acids. What will You do if this TBN base number is reduced to a low level?
A Renew lub oil in the system.
B Send one lub oil sample to new analysis.
D Purify the oil system.
178.What can happen with a lub. oil cooled piston if you stop the lub. oil pump immediately after You stop the engine?
A Nothing happens.
B The oil flashpoint will be changed.
C Overheating of the piston, and oil coke deposits in the cooling chambers
D You save the oil sealings in the piston.
179.You have checked the oil viscosity in an auxiliary engine with the viscosity test kit. The result shows that the viscosity is high. What will you do?
A Decrease the cooling water temperature for the oil.
B Clean the system and change the oil
C Increase the cooling water temperature for the oil.
D Increase the lub oil pressure.
180.You have checked the oil viscosity in an auxiliary engine with the viscosity test kit. The result shows that the viscosity is low. What will you do?
A Clean the system and change the oil.
B Increase the oil temperature.
C Start to purify the oil.
D Decrease the oil temperature.
181.What could be the reason if the lub oil viscosity increase?
A Heavy fuel oil leakage to the lub oil system.
B The lub oil viscosity will not increase.
C Water-leakage to the lub oil system
D High lub oil temperature.
182.What could be the reason if the lub oil viscosity decrease?
A Heavy fuel oil leakage to the lub oil system.
B Diesel oil leakage to the lub oil system
C Low lub oil temperature.
D Wrong lub oil pressure
183.A water content greater than 2 % is detected in a lub oil system. What is the best action to do?
A Continuous purifying the system with the lub oil pumps running.
B Boil out the water by increasing the temperature.
C Segregate the oil in a seperate tank for continuous purifying.
D It is no danger before the water level reach 6-8%.
184.What long term effect will excessively high temperature have on lubricating oil quality?
A Cause oxidation which reduce viscosity.
B Evaporates the oil giving high consumption.
C The oil flashpoint will be changed.
D Cause oxidation which increase viscosity.
185.Which would be the most suitable place to obtain an oil sample for analysis?
A From the lub. oil pump suction line.
B From the system pipeline
C From the oil cooler drain.
D From the filter drain.
186.If water contamination occurs in the crankcase oil of an auxiliary engine the oil viscosity will:
B Nothing happens.
C Stay at the same.
187.What type of lubricating oils are generally used in auxiliary engines?
D It is not important.
188.In a Burmeister & Wain main engine, at what point is cylinder oil injected?
A Just before "Top Dead Centre".
B As the piston passes "The Lubrication Points" in a downward direction
C As the piston passes "The Lubrication Points" in an upward direction
D Just before "Bottom Dead Centre"
189.What differential pressure would you expect to find across an engine lub.oil filter?
A 1.2 Bar
B 3.0 Bar
D 0.2 Bar
190.You notice the sump level in an engine has increased and no new oil has been added. What action would you take?
A Drain some oil from the engine.
B Stop the engine and look for a fuel or water leak.
C Reduced the load, and look after fuel or water leak.
D Leave it the same.
191.Oil analysis results show a high level of tin. What could be the cause of this?
A Bearing damage.
B Water contamination.
C Fuel contamination
D Too high lub.oil temperature.
192.We have two kinds of turbocharging systems: constant pressure and impulse. The difference between these two can be found in:
A The exhaust gas receiver.
B Scavenging air coolers.
C The blades on the exhaust gas turbine.
D The scavenging valves of the engine.
193.We have a problem with surging in the turbocharger. Which of the following could be the cause?
A Worn out bearings on the turbocharger.
B The lubrication oil pump is malfunctioning.
C Dirty rotor blades.
D Dirty scavenging air cooler on the air side.
194.The revolutions on the turbocharger have increased during the night with unmanned engine. Could this be caused by:
A The viscosity of the fuel is to high.
B We have favourable winds and current.
C The current and wind are holding the vessel back
D Poor combustion due to malfunction of fuel valves
195.The turbocharger (constant pressure) is making "whoofing" noises. What might be the cause?
A Heavy seas from behind.
B A faulty turbocharger bearing.
C One or more leaking exhaust-valve(s).
D Strong current against
196.After how many hours would you consider changing the turbocharger bearings, even though all appears to be normal?
A 12.000 hours.
B 4.000 hours.
C 25.000 hours.
D 30.000 hours.
197.The timing of the engine is delayed. The exhaust temperatures are high. How would you expect this to affect the turbocharger?
A Decreased turbocharger revolutions.
B Surging of the turbocharger.
C Increased turbocharger revolutions
D Higher air and gas temperature after turbocharger.
198.We have a problem with vibration in the turbocharger. What might be the cause?
A Dirty air inlet filter.
B The turbine rotor is not balanced
C The lubricating oil needs to be changed.
D Worn out turbocharger bearings.
199.With full load on the main engine, the RPM for the turbocharger is too low. What may cause this?
A The diffuser ring is damaged.
B Exhaust temperatures on the main engine are too high.
C Dirty nozzle ring.
D The lubricating oil pump is malfunctioning.
200.With full load on the main engine, the turbocharger tachometer reads: Too low RPM. Why?
A Damaged connection between pick-up and tachometer unit
B Pick up is not connected to turbocharger.
C Turbocharger need to be cleaned/overhauled.
D Pick up for tachometer is wrongly adjusted.
201.The lubricating oil on the exhaust side of the turbine blower gets very dirty after only a few hours in service. What can the reason be?
A Exhaust gas leaking into the oil chamber.
B Wrong type of oil used.
C Lubricating oil is mixed with salt water
D Worn out bearing turbine side
202.After water-washing the turbocharger exhaust side, the blower starts to vibrate. What has happened?
A Water drain for washing system is clogged.
B Foundation bolts for the blower unit are loose
C The rotor blades are damaged or the blades are not properly cleaned
D Inlet filter partly clogged.
203.The blower's air delivery is not sufficient. What is the cause?
A Air temperature in engine room too high.
B Dirty scavenge duct.
C Clogged air inlet filter.
D Cooling water temperature too high
204.Why is it important to slow down the main engine RPM while water-washing the turbocharger?
A To protect the bearings.
B To protect the exhaustgas economizer.
C To protect the blower side.
D Not to damage the rotor blades.
205.Some engine manufacturers recommend that washing of the compressor side is not carried out. Is this due to:
A Greasy sludge from the compressor sticking between the fins in the air coolers, necessitating extra cleaning of these.
B Large volumes of water being carried over into the cylinders of the engine.
C The nozzle ring becoming corroded
D The thermal shock exhibited by the vanes.
206.What is the meaning of the term "valve clearance"?
A The clearance between the rocker arm and valve pushrod.
B The clearance between valve spindle disc and seat.
C The clearance between the rocker arm and camshaft pushrod.
D The clearance between the rocker arm and valve pushrod in either warm or cold state.
207.The meaning of lapping a valve and valve seat is:.
A Adjust the overlapping of the inlet and exhaust valves.
B Grind the valve against the valve seat to obtain a uniform sealing surface.
C Machining the valve in a lathe machine.
D Repair by welding.
208.Some 4-stroke engines are fitted with a rotorcap on the cylinder head valves. For what reason?
A Rotate the inlet valve during operation.
B Distribute the exhaust gas or the air inlet better to improve combustion.
C Improve the scaling surface function, increase the service time of the exhaust valve in the engine
D To prevent the valve spindle from sticking..
209.When overhauling the cylinder covers on a modern 4-stroke engine, is it important not to interchange inlet and exhaust valves?
A Not so important.
B Important due to different material and working conditions.
C Can be changed if same size.
D Important due to different type size valve guide.
210.What is the purpose of the cylinder head safety valve?
A To relieve excessive high pressure in the cylinder to protect the engine from being damaged.
B To adjust the cylinder pressure to a safe working pressure.
C A valve for safety stop (emergency) of the engine.
D For indication of engine being overloaded.
211.Most of the engine makers recommend to change the cylinder head gaskets each time a piston overhaul is carried out. Why?
A To obtain a proper sealing and correct distance between piston and cover in TDC position.
B To increase the consumption of parts so they can make more money.
C To avoid heat transfer to the cylinder head.
D To be granted a proper sealing with a new gasket.
212.Some 4-stroke engines are equipped with cooled fuel valves. Why is it so important to keep the coolant's temperature correct?
A For cooling only.
B For preheating only
C To avoid overheating the fuel nozzle
D For cooling and to maintain correct viscosity on the fuel when injected
CAPT AJIT VADAKAYIL
29 YEARS IN COMMAND
MAIN ENGINE ANSWERS