diesel sorular son

8/3/2019 Diesel Sorular Son

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KAAN KURTULU

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

A a leaking fuel injection nozzle

B a clogged air filterC early fuel injection

D burned valves

Diesel engine exhaust temperatures may be used to indicate __________.

A leaking exhaust valves

B an overloaded cylinder

C a clogged injector nozzle

D all of the above

Significant retardation of diesel engine fuel injection timing will result in __________.

A decreased ignition lag

B advanced fuel ignition

C increased fuel economy

D reduced engine power

Which of the following problems could develop due to the accumulation of oil vapors in the crankcase of a diesel engine?

A Reduced lubrication

B Poor fuel economy

C Combustion knock

D Crankcase explosion

In a naturally aspirated diesel engine, the volume of air intake is directly associated with engine __________.A compression ratio

B displacement

C fuel pressure

D cylinder clearance volume

White smoke exhausting from a diesel engine can result from __________.

A high exhaust temperature

B high lube oil temperature

C low turbo charge speed

D low cooling water temperature

Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?

A Compression must be low for effective spark ignition.B Compression must be low for smooth operation.

C The heat of compression is not used as an ignition source of the fuel.

D Compression must be low to have effective preignition.

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

A improperly seating intake valves

B leaking cylinder liner seal rings

C late fuel injection timing

D carbon deposits on the piston

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

A fuel will not be properly atomized in the cylinder

B ignition will be delayed due to low ignition temperature

C maximum fuel expansion will occur on the compression stroke

D fuel will ignite before top dead center


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

A excessive lube oil consumption

B lower than normal lube oil temperature

C higher than normal exhaust back pressure

D excessive crankshaft end play

The desirable properties of a marine fuel oil should include __________.

A high flash point and high viscosity

B low flash point and high viscosity

C low heating value and high sulphur content

D high heating value and low sulphur content

The time between injection and ignition of the fuel is known as __________.

A turbulence lag

B after burning ratio

C injection lag

D ignition delay

Diesel engine exhaust valve springs are under compression when the valves are __________.

A wide open only

B partially open only

C closed only

D in any position

Which of the following conditions is most likely to occur if oil containing moisture is continuously fed to a purifier operating as a clarifier?

A The purifier must be operated at a higher temperature.

B The purifier must be operated at a higher speed.

C The purifier will gradually change operation to separation.

D The bowl will eventually fill with water.

When a piston is removed from a diesel engine for maintenance, the piston should be examined for __________.

A scoring

B cracks and burned spots

C gummy deposits and sticking rings

D all of the above

FATH ENTRK

1-)A smoking exhaust from an operating diesel engine could be caused by __________.

A low sulfur content in the fuel

B a loose injector inlet connection

C late fuel injection

D high injection pressure

2-)A diesel engine will lose power if fuel injection occurs too early because the __________.

A fuel will not be properly atomized in the cylinder

B ignition will be delayed due to low ignition temperature

C maximum fuel expansion will occur on the compression stroke

D fuel will ignite before top dead center

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

A To prevent internal damage from local overheating.

B To ensure the fuel nozzles are flushed clean.

C To clear the smoke stack.

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

4-)Which of the listed factors will indicate the most about the ability of a fuel to ignite in a diesel engine?


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A Viscosity

B Sulfur content

C Pour point

D Cetane number

5-)High diesel engine cooling water temperatures can be caused by __________.

A air in the cooling system

B an open thermostat

C maintaining only 1/2 an expansion tank levelD excessive cooling water pump pressures

6-)Lubricating oil used in a diesel engine serves to __________.

A reduce the wear of bearing surfaces

B cool the bearing surfaces

C assist in sealing bearing surfaces

D all of the above

7-)A leaking diesel engine fuel injector will cause __________.

A prolonged maintenance intervals

B improved atomization

C greater fuel economy

D incomplete combustion

8-)Which of the listed set of conditions indicates early fuel injection timing?

ALoss of engine power and high exhaust temperatures

BHigher than normal firing pressure and low exhaust temperature

CHigh fuel consumption and high exhaust temperaturesDLower than normal compression pressure and high exhaust temperature

9-)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?

A Advanced ignition

B Clogged air intake

C Leaky exhaust valve

DHigh exhaust pressure

10-)Poor combustion in a diesel engine operating with blended fuel oil can be caused by __________.

A high compression pressureB high fuel oil viscosity

C low exhaust pressure

D high scavenge air pressure

11-)When fuel oil has seriously contaminated a diesel engine lubricating oil, you should __________.

A filter to remove the fuel oil

B use the settler to remove the fuel oil

C remove the fuel oil by centrifuging

D drain and then renew the lube oil supply

12-)Excessive lubricating oil consumption in a running diesel engine can be caused by __________.

A clogged lube oil piping

B excessive valve-guide clearanceC high lube oil viscosity

D low lube oil temperature

13-)Diesel engine cylinder head test cocks are used to __________.

A check cylinder lubrication prior to starting engine

B connect exhaust gas analyzers to determine engine efficiency

C pressure test cylinder heads to check for leaks

D remove moisture accumulations from cylinders prior to starting

14-)Injection pressure in a common rail fuel system is controlled by __________.

A engine speed

B varying the fuel pump piston stroke

C varying the injector needle valve clearanceD a bypass valve


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6.Distortion of the spray pattern of a nozzle or injector may be indicated bya/an __________.

A.high firing pressureB.overload of that particular cylinder

C.smoky exhaustD.cooling water temperature rise

7.Which of the events listed does NOT occur during the instant the pistonjust reaches top dead center?

A. IgnitionB. CombustionC. IntakeD. Power

8.Significant retardation of diesel engine fuel injection timing will result in__________.

A. decreased ignition lagB. advanced fuel ignitionC.reduced engine powerD. increased fuel economy

9.One remedy for a high firing pressure, in addition to a high exhaust

temperature in one cylinder of a diesel engine, is to __________.A. increase scavenge air pressureB. reduce fuel booster pump pressureC. retard fuel injector timingD. adjust the fuel rack

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

A. push rods

B. piston rods

C. connecting rodsD. piston guides

11.Fuel is admitted to a diesel engine cylinder through the __________.

A intake valves

B carburetor

C exhaust portsD injection nuzzle


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12.In a four-stroke/cycle medium-speed diesel engine, fuel injection

commences at 10 crankshaft degrees before top dead center. After fuel

injection commences, approximately how many degrees will the camshaft

rotate before the exhaust valve begins to open?A.10- 25B.30- 55C.100- 130

D.60- 8013.Injection pressure in a common rail fuel system is controlled by

__________.A.a bypass valveB.varying the injector needle valve clearance

C.varying the fuel pump piston stroke

D.engine speed14.The start of fuel oil injection into the cylinder of a four-stroke/cycle

diesel engine occurs during the __________.A.exhaust strokeB.power strokeC.compression strokeD.intake stroke15.Late fuel injection timing is indicated by __________.

A.lower than normal cylinder pressure and low exhaust temperature

B.lower than normal cylinder pressure and high exhaust temperatureC.higher than normal cylinder pressure and low exhaust temperature

D.higher than normal cylinder pressure and high exhaust temperature1.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 vapors

D. combustion byproducts removed from the cylinder walls

2.One function of diesel engine lubricating oil is to __________.

A. induce carbon formation on cylinder walls

B. improve fuel penetration in the combustion space


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C. form a friction reducing film between mating surfaces

D. lubricate the fuel injectors

3.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

4.The most rapid period of fuel combustion and cylinder pressure increase in a diesel

engine should begin just before the piston reaches top dead center and should be

completed __________.

A. shortly before bottom dead center

B. shortly after bottom dead center

C.immediately after injection lag

D. shortly after passing top dead center

5.The most effective method in removing water from diesel fuel oil is by __________.

A. centrifuging the fuel

B. using it in the engine

C. heating the fuel tanks

D. straining the fuel

6.Scuffed cylinder liner wearing surfaces in a diesel engine can result from __________.

A. starting the engine while hot

B. knurling the piston skirt

C. operating the engine overheatedD. scuff resistant piston rings

7.If a two-stroke/cycle diesel engine is overspeeding due to leakage of lube oil into the

cylinders, what should you do to stop the engine?

A. Move the fuel control mechanism to the no fuel position.

B. Block the fuel supply by closing the master fuel valve.

C. Shut off the fuel supply and block the flow of intake air.

D. Relieve all pressure in the fuel system.

8.Worn diesel engine intake valve guides can result in __________.

A. increased engine breathing efficiencyB. excessive valve lash

C. excessive lube oil consumption

D. lower than normal fuel consumption

9.Which of the following problems may occur when using fuel oil with a high sulphur

content?

A. Injection lag

B. Lube oil dilution

C. Pre-ignition

D. Corrosion

10.In a diesel engine, maximum lube oil system pressure under cold start conditions, isnormally controlled by __________.


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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

11.Which of the listed substances can be satisfactorily removed from diesel fuel bycentrifuging?

A. Sludge

B. Gasoline

C.Fuel oil

D. Lube oil


A. push rods

B. piston rods

C. connecting rods

D. piston guides

13.Which of the following conditions will tend to increase the ignition delay period of

combustion in a compression ignition engine?

A. Using a fuel oil with a higher cetane number.

B. Decreasing the air charge temperature.

C. Reducing the injected fuel oil droplet size.

D. Increasing the compression ratio.

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

__________.

A. lube cooler failureB. poor heat transfer

C. mechanical lubricator failure

D. camshaft seizure

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

A dust entering the first stage

B lube oil carbonization

C discharge pulsations

Dinterstage vapor lock,


A intake valves

B carburetor

C exhaust ports

D injection nuzzle

GRKEM ELMALIPINAR

1.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 usedC. condensation of water vapors


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D. combustion byproducts removed from the cylinder walls

2.One function of diesel engine lubricating oil is to __________.

A. induce carbon formation on cylinder walls

B. improve fuel penetration in the combustion spaceC. form a friction reducing film between mating surfaces

D. lubricate the fuel injectors

3.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

4.The most rapid period of fuel combustion and cylinder pressure increase in a dieselengine should begin just before the piston reaches top dead center and should be

completed __________.

A. shortly before bottom dead center

B. shortly after bottom dead center

C.immediately after injection lag

D. shortly after passing top dead center

5.The most effective method in removing water from diesel fuel oil is by __________.

A. centrifuging the fuel

B. using it in the engine

C. heating the fuel tanksD. straining the fuel

6.Scuffed cylinder liner wearing surfaces in a diesel engine can result from __________.

A. starting the engine while hot

B. knurling the piston skirt

C. operating the engine overheated

D. scuff resistant piston rings

7.If a two-stroke/cycle diesel engine is overspeeding due to leakage of lube oil into the

cylinders, what should you do to stop the engine?

A. Move the fuel control mechanism to the no fuel position.B. Block the fuel supply by closing the master fuel valve.

C. Shut off the fuel supply and block the flow of intake air.

D. Relieve all pressure in the fuel system.

8.Worn diesel engine intake valve guides can result in __________.

A. increased engine breathing efficiency

B. excessive valve lash

C. excessive lube oil consumption

D. lower than normal fuel consumption

9.Which of the following problems may occur when using fuel oil with a high sulphur

content?


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A. Injection lag

B. Lube oil dilution

C. Pre-ignition

D. Corrosion

10.In a diesel engine, maximum lube oil system pressure under cold start conditions, 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

11.Which of the listed substances can be satisfactorily removed from diesel fuel by

centrifuging?

A. Sludge

B. Gasoline

C.Fuel oil

D. Lube oil


A. push rods

B. piston rods

C. connecting rods

D. piston guides

13.Which of the following conditions will tend to increase the ignition delay period of

combustion in a compression ignition engine?

A. Using a fuel oil with a higher cetane number.

B. Decreasing the air charge temperature.C. Reducing the injected fuel oil droplet size.

D. Increasing the compression ratio.

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

__________.

A. lube cooler failure

B. poor heat transfer

C. mechanical lubricator failure

D. camshaft seizure

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

A dust entering the first stageB lube oil carbonization

C discharge pulsations

Dinterstage vapor lock,


A intake valves

B carburetor

C exhaust ports

D injection nuzzle


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MER SALI

The sequence of events in a cycle within 4 stroke diesel engine is:

1- The piston is forced down at BDC (Bottom Dead Center) exhaust valveopens

2- The piston is at the top of its stroke, TDC (Top Dead Center), inletvalve opens, fresh air is drawn

3- Pressure is high in the gases

4- Fuel is injected as the piston reaches TDC, to start the combustion

5- Inlet valve opens, fresh air drawn as the piston moves down

6- At the bottom of the stroke BDC inlet valve closes and the air incylinder is compressed as the piston rises

1) 2-5-6-4-3-1

2) 2-5-6-4-1-3

3) 2-6-5-4-3-1

4) 5-2-4-6-3-1

5) 5-2-6-4-1-3

On most diesel engines, the governor controls the speed by:

1) Controlling the amount of fuel injected into the cylinders

2) Varying the speed of the turbocharger

3) Adjusting the compression ratio

4) Changing the timing of the fuel injection camshaft

5) Changing the timing of the exhaust valves

"The intake valve is open and exhaust valve is closed. The air is drawn into


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cylinder while the piston is moving downward" defines;

1) power stroke

2) compression stroke

3) intake stroke

4) exhaust stroke

5) combustion

If one cylinder was getting more fuel then others the effect will be ...............

1) That cylinder's being overloaded

2) The exhaust valve's being overheated

3) Average compression

4) Incomplete combustion

5) Complate combustion

Which of the followings is not one of the qualities of the governor?

1) The main control device on the engine

2) Controls the engine speed when the power is required to change

3) The supplementary control device on the engine

4) Can be adjusted automatically

5) Made up of speed sensing arrangement and hydraulic unit

Blue smoke coming from the diesel exhaust would indicate:

1) Excessive fuel consumption / unburned fuel

2) Burning of lube oil due to possible blow by

3) Lean fuel / air mixture, too much air

4) Less amount of fuel consumption


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5) None of the above

When does a two stroke cycle diesel engine produce a power stroke in eachcylinder

1) Once in every 2 revolutions of the crankshaft

2) Once for every 4 stroke of the piston

3) Once for every 2 stroke of the piston

4) Directly after the exhaust stroke

5) None of the above

"The intake valve is open and exhaust valve is closed. The air is drawn intocylinder while the piston is moving downward" defines;

1) power stroke

2) compression stroke

3) intake stroke

4) exhaust stroke

5) combustion

In a 2 stroke engine each revolution of the crank is completed within theangle of ......

1) 360

2) 180

3) 720

4) 90

5) 45

What would cause white smoke after you just started the diesel?

1) Too week battery power

2) Water in the fuel


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3) Water in the gas

4) Water in the oil

5) Salt water in cooling water

An over speeding diesel engine could best be stopped by:

1) Disconnecting the battery cables from the stating motor

2) Blocking the air intake and securing the fuel supply

3) A raining the hydraulic fluid from the governor sump

4) Blocking the flow of cooling air to the radiator

5) Both 3 and 4

Fuel is ignited in the cylinder of an operating diesel engine by:

1) The heat of compression within the cylinder

2) A spark plug in the pre-combustion chamber

3) An electrical discharge from the distributor

4) Heat from the fuel injection nozzle

5) With a simple spark plug

What would cause white smoke after you just started the diesel?

1) Too week battery power

2) Water in the fuel

3) Water in the gas

4) Water in the oil

5) Salt water in cooling water

Scavenging means .......................... on an internal combustion engines.

1) The removal of exhaust gases by blowing in fresh air


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2) The filling of the engine cylinder with a supply or change of fresh air

3) The formation of exhaust gases within the cylinder

4) The removal of exhaust gases

5) Any above

In the simple mechanical governor, the:

1) Flyweight centrifugal force is balanced by spring pressure

2) Centrifugal force rotates the ball head

3) Flyweight centrifugal force is balanced by hydraulic pres sure

4) Speeder spring actuates the fuel control rod

5) Hydraulic force rotates the ball head

MERT ERSZ

The successive order of 4 stroke diesel engines:

1) Compression - suction - firing - exhaust

2) Suction - firing - compression - exhaust

3) Suction - compression - exhaust - firing

4) Suction-compression - firing - exhaust

5) Compression - air inlet - firing exhaust

When the valves are operated ........................... on a diesel engine, they areactuated by means of cams, pushrods, rocker arms and rollers.

1) Mechanically

2) Hydraulically

3) Pneumatically

4) Electrically

5) Any above


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Emergency generators can be stopped via ....................................

1) Ovelvoltage trip

2) Overspeed trip

3) Manual trip

4) Undervoltage

5) Any above

When maneuvering, you discover heavy smoke coming from the turbochargercasing. You should:

1) Check the air fitler for dirty

2) Check for an exhaust leak

3) Check the cooling water temperature

4) Notify the bridge and ask to shut the engine down

5) Check fuel oil consumption

A device which will function to bring an engine to a full stop in order toprotect it from damage due to excessively high speed is known as a/an:

1) Torque limiter

2) Overspeed trip

3) Overspeed governor

4) Load limit governor

5) Any of above

The main characteristics of a diesel engine is:

1) internal combustion engine; the fuel is burned external of the cylinders

2) producing high power of energy

3) either 2 or 4 stroke, fuel is burned inside the cylinders


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4) economical in compare with the steam engines, but hard maintenance

5) fixed sequence of events within its unique type

Considering the fuel, ignition quality is determined by .......................

1) Cetane number

2) Diesel index

3) Calculated cetane index

4) Flashpoint

5) All except 4

.................... is hardly the cause of a smoky diesel engine exhaust.

1) Overload

2) Malfunctioned injector

3) Choked exhaust pipe

4) Inappropriate amount of fuel

5) Appropriate amount of fuel

In a 4 stroke engine 2 revolution of the crank is completed within the angleof ....................

1) 720

2) 360

3) 180

4) 90

5) 45

Which one is not identical with the characteristics of the construction of a-2-stroke diesel engines?

1) Instead of valve holes, ports are installed


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2) A cycle is completed in 2 strokes of the piston

3) Produce high power in compare with 4 stroke engines

4) The maintenance is simple

5) A cycle is completed in 2 revolution of the crackcase

.......................... are the common parts within the 2 and 4 stroke dieselengines.

1) Piston, valves, cylinder, fuel injector

2) Crankshaft, crosshead, cylinder

3) Turbocharger, piston, gudgeonpin, cylinder

4) Crankshaft, connecting rod, pistons

5) Cylinder, connecting rod, pistons

The power produced in the cylinder is called ..........................

1) Cycle

2) Combustion

3) Break horse power(BHP)

4) Indicated horse power(IHP)

5) RPM

Every mechanical governor has ......................... as its basic element.

1) Power piston

2) Control rack

3) Weights acted on by centrifugal force

4) Isochronous droop spring

5) Piston

VOLKAN TEMIZER130070409


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1-

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

A raise lube oil viscosity for easier starting in cold weather

B increase air inlet temperatureC increase compression ratioD increase jacket water temperature for easier starting in cold weather

2-

Piston compression rings used in a diesel engine function to __________.

A transfer heat from the cylinder to the pistonB scrape oil from the sides of the pistonC seal the combustion space from the crankcase

D prevent any piston contact with the cylinder liner

3-

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

A the production of high pressure gasesB the removal of expended combustion gasesC the admission of air to the cylinderD All of the above

4-In a four-stroke/cycle diesel engine, after the completion of the power stroke, the piston wi

A up and draw in a fresh air chargeB down to burn off fuelC down to compress the fuel air chargeD up and force out the exhaust gases

5-

A diesel engine valve spring is under compression when the valve is __________. I. open I

A I onlyB II onlyC both I and IID neither I nor II

6-

Successful combustion inside the cylinders of a diesel engine is dependent upon ________

A fine atomizationB high temperature

C proper mixing of fuel and airD all of the above


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7-

A four-stroke eight cylinder in-line medium speed diesel engine has a firing order of 1-5-2-at TDC and firing, how many degrees of camshaft rotation will occur when #1 piston reach

A 120 degreesB 180 degreesC 240 degreesD 360 degrees

8-

On most diesel engines, the governor controls the output speed by __________.

A controlling the amount of fuel injected into the cylindersB varying the speed of the turbocharger

C adjusting the compression ratioD changing the timing of the fuel injection camshaft

9-

Turbocharged four-stroke/cycle diesel engines utilize valve overlap for __________.

A improving cylinder scavengingB preheating the combustion chamberC reducing air charge densityD preventing valve wear

10-Which statement about diesel engine combustion is true?

A Combustion does not begin until the piston starts down on the power stroke.B Maximum combustion pressure is reached before TDC.C Turbulence in the cylinder causes a delay in ignition.D Maximum cylinder firing pressure is not developed until the piston passes TDC.

11-

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

A carbon deposits on the piston crownB leaking cylinder liner seal ringC poor quality fuelD worn crankshaft and crankpin bearings

12-

The efficient burning of fuel in a diesel engine is dependent upon the __________.

A temperature of compressionB atomization of the fuel

C penetration of the fuelD all of the above


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13-

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

A At TDC by heat generated by compression.B Just before TDC by heat generated by compression.

C Just before TDC by spark ignition.D At TDC by spark ignition.

14-

Auxiliary diesel engines can be automatically shut down as a result of __________.

A low lube oil temperatureB low lube oil pressureC high exhaust temperatureD high cooling water pressure

15-

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

A spark from a plug in the pre-combustion chamberB electrical discharge from the distributorC heat of compression within the cylinderD heat from the fuel injection nozzle

16-

The degree of fuel atomization in a diesel engine cylinder depends primarily on _________A the size of the holes in the fuel nozzleB timing of the pumpC supply pressure to the pumpD shape of the combustion chamber

17-

n a naturally aspirated diesel engine, the volume of air intake is directly associated with en

A compression ratio

B displacementC fuel pressureD cylinder clearance volume

18-

When accumulated carbon at the air inlet ports of a two-stroke/cycle diesel engine is beingcare to avoid carbon __________.

A entering the cylinderB particles becoming lodged under the intake valves

C entering the water jacketD particles entering lube oil


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19-

A diesel engine may be hard to start if the __________.

A air intake is restricted

B engine is cranked too fastC vibration dampener is faultyD exhaust back pressure is low

20-

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

A crankcase pressureB compression pressureC scavenge air pressure

D exhaust manifold pressure

DENZHAN EKEM130070405

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

A leaking delivery valveB increase in engine load

& C plugged injector spray hole

D increased plunger stroke

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

A it has a longer power strokeB more air gets into the cylinder each stroke

& C it develops twice as many power strokes at the same speedD higher combustion pressure is developed

A diesel engine exhaust valve spring is under compression when __________.A the valve is openB the piston is at top dead centerC the valve is closed

& D all of the above

The compression ratio of a diesel engine refers to the ratio between the __________.A piston area to connecting rod length

& B cylinder volumes at top dead center and at bottom dead centerC engine cylinder size to piston sizeD the number of compression strokes for a given horsepower


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A disadvantage of a two-stroke/cycle diesel engine is __________.A more power strokes per revolution

B the use of scavenge airC more complicated valve gear

& D higher working temperatures of the piston and cylinder

If a diesel engine's exhaust temperature is abnormally high, the cause could be __________.A too light of a loadB injection timing is too early

& C overloading of the engineD too low of a compression ratio

An increase in the load on a turbocharged diesel engine operating at constant speed willresult in an increase in __________.

A exhaust temperatureB air box pressureC mean effective pressure

& D all of the above

An increase in the load on a turbocharged diesel engine operating at constant speed willresult in an increase in __________.& A exhaust temperature

B air box pressureC mean effective pressure

D all of the above

Poor combustion in a diesel engine can be caused by __________.A high compression pressure

& B low compression temperature

C low exhaust pressureD high scavenge air pressure

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

A high cetane number& B insufficient compressionC low lube oil viscosityD high lube oil pressure

In a single acting, two-stroke/cycle, diesel engine, the power impulse in an individualcylinder occurs __________.& A once every crankshaft revolution

B once every two crankshaft revolutions

C once every piston strokeD twice every piston stroke


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

A has little or no internal friction

B has a lower effective compression ratioC operates with scavenge air under a positive pressure

& D operates without energy absorbing intake and exhaust strokes

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

A injection lag& B ignition delay

C compression ignition

D turbulence lag

In a diesel engine, blow-by __________.A increases exhaust back pressure

& B causes excessive crankcase pressureC can only be detected by a compression checkD decreases fuel consumption

Early fuel injection timing is indicated by the cylinder pressure being __________.& A above normal with a below normal exhaust temperature

B above normal with a normal exhaust temperatureC below normal with a normal exhaust temperatureD below normal with an above normal exhaust temperature

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

& B early fuel injectionC high exhaust temperature from that cylinder

D decreased effective stroke from that injector

AL DARI130070420

1)

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

A twice the crankshaft speed

B half the crankshaft speed


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C the same speed as the crankshaft

D a speed independent of the crankshaft

ANSWER:C

2)

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

A At TDC by heat generated by compression.

B Just before TDC by heat generated by compression.

C Just before TDC by spark ignition.

D At TDC by spark ignition.

ANSWER: C

3)

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

ANSWER:D

4)

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

ANSWER:A

5)


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A smoking exhaust from an operating diesel engine could be caused by __________.

A low sulfur content in the fuel

B a loose injector inlet connection

C late fuel injection

D high injection pressure

ANSWER: C6)

Late fuel injection in a diesel engine is indicated by black or gray exhaust smoke with a __________.

A low firing pressure

B low exhaust temperature

C mechanical knock in each cylinder

D low compression pressure

ANSWER:A7)

The highest pressure in a diesel engine cylinder normally occurs __________.

A at TDC

B before TDC

C after TDC

D during air starting

ANSWER:C8)

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

A The exhaust valve closes.

B Exhaust blow down occurs.

C Pressure in the cylinder increases.

D Volume in the cylinder decreases.

ANSWER:B


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9)

When an air started, four-stroke/cycle diesel engine is being cranked over, the starting air is admitted to eachcylinder during the beginning of its __________.

A intake stroke

B compression stroke

C power stroke

D exhaust stroke

ANSWER:C

10)

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

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

B two crankshaft revolutions in a two-stroke/cycle engine

C two power strokes in a two-stroke/cycle engine

D two piston strokes in a four-stroke/cycle engine

ANSWER: A11)

Fuel is ignited in a diesel engine cylinder by __________.

A a spark plug

B injectors

C the heat of compression

D increasing jacket water temperatures


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ANSWER: C

12)

In a four-stroke/cycle diesel engine, badly worn intake valve guides can cause excessive __________.

A exhaust pressure

B exhaust temperatures

C cooling water temperatures

D lube oil consumption

ANSWER: D13)

The camshaft on a four-stroke/cycle diesel engine is used to operate the __________.

A fuel injectors

B exhaust valves

C intake valves

D all of the above

ANSWER: D14)

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

A double-acting engine

B opposed piston engine

C single-acting engine

D horizontal acting engine

15)

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


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shutdown, the __________.

A fuel must be preheated

B intake air should be preheated

C lube oil outlet temperature should be increased 20 above normal

D none of the above

ANSWER:A

ILTERIS SAY

1.The shape of a diesel engine cam determines the __________.A points of opening and closing of the valveB velocity of opening and closing of the valveC amount of the valve lift from its seatD all of the above(D is the right answer)

2.Incomplete combustion in a running diesel engine can cause piston rings to become stuckas a result of __________.A residual carbon depositsB lube oil viscosity breakdown

C uneven heat expansion of the ringsD uneven heat expansion of the piston

(A is the right answer)

3.One function of diesel engine lubricating oil is to __________.A induce carbon formation on cylinder wallsB improve fuel penetration in the combustion spaceC form a friction reducing film between mating surfacesD lubricate the fuel injectors(C is the right answer)

4.Intercoolers installed on starting air compressors, reduce the possibility of __________.A dust entering the first stageB lube oil carbonizationC discharge pulsationsD interstage vapor lock(B is the right answer)

5.Diesel engine injection lag is caused by __________.A compressibility of the fuel


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A The piping shall be so arranged to allow for uncomplicated removal of the fuel injectionequipment and other associated components located on the cylinder head.B All high pressure piping shall be of the double lined type, with the outer leak off linesuitably channeled to a dedicated tank.C All storage tanks connected to the leak off piping of fuel injection systems shall be

provided with high level alarms and sufficient means for emptying.D The piping is to be effectively shielded and secured to prevent fuel or fuel mist fromreaching a source of ignition on the engine or its surroundings.(D is the right answer)

11.The start of fuel oil injection into the cylinder of a four-stroke/cycle diesel engine occursduring the __________.A intake strokeB exhaust stroke

C power stroke

D compression stroke(D is the right answer)

12. Which of the indicator diagrams illustrated in Illustration MO-0029 depicts the conditionthat should be corrected by retarding only the timing?A AB BC CD D(A is the right answer)

13. A fuel injection valve opening at a pressure lower than normal will result in __________.A late fuel injectionB early fuel injectionC high exhaust temperature from that cylinderD decreased effective stroke from that injector(B is the right answer)

14. To minimize the formation of carbon deposits on fuel injection nozzles, you should__________.

A avoid using liquid-cooled nozzles whenever possibleB avoid low cooling water temperaturesC avoid prolonged overloading of the engineD make certain the gasket seal between the nozzle and cylinder head is tight(C is the right answer)

15. In order to determine the fuel pump rack setting for individual fuel pumps on the dieselengine shown in the illustration MO-0005, you must __________.A secure the engine and remove the fuel pump crosshead coverB remove the fuel pump crosshead cover and observe the rack setting with the engine

running


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C secure the engine, remove the fuel pump crosshead cover, and compare rack setting tomaster pump settingD run engine at idle, remove cover, and secure engine while observing rack movement(B is the right answer)


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Kamer Sarihan

Which of the conditions listed occurring in a diesel engine would cause carbon deposits to

develop in the piston ring belt?A Faulty combustionB Excessive ring temperatures

C Over lubricationD All of the above.

The color of the engine exhaust from a diesel propelled ship should be __________.A clearB hazy light brownC hazy light blueD hazy light gray

Which of the following conditions will tend to increase the ignition delay period of

combustion in a compression ignition engine?A Using a fuel oil with a higher cetane number.B Decreasing the air charge temperature.C Reducing the injected fuel oil droplet size.D Increasing the compression ratio.

Before installing rings on a diesel engine piston, you should check the ring __________.A diametrical tensionB gap clearanceC radial thickness

D outside diameter

The upper piston rings in large, slow-speed, two-stroke/ cycle diesel engines are mosteffectively lubricated by oil __________.A fed from mechanical lubricators

B thrown off from the main bearingsC supplied from wick fed drip lubricatorsD flow from a centrifugal or banjo oiler

A burned exhaust valve may be detected by a higher than normal __________.A firing pressureB exhaust temperature from a particular cylinderC cooling water temperatureD compression pressure

The average exhaust temperature of a two-stroke/cycle diesel engine with a turbine-drivensupercharger is lower than a similar four-stroke/cycle diesel engine at equal loads because

__________.A two-stroke/cycle diesel engines have a higher M.E.P. than four-stroke/cycle diesel engines

B two-stroke/cycle diesel engine exhaust is cooled by the scavenging air chargeC four-stroke/cycle diesel engines have a higher RPM than two-stroke/cycle diesel engines


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D the opening of the two-stroke/cycle diesel exhaust ports or valves occurs much later thanin four-stroke/cycle diesel engines

Which of the following conditions is realized by the turbo charging of a previously naturallyaspirated diesel engine?

A Ignition lag increases.B Lube oil system pressure increases.C Brake specific fuel consumption increases.D Mechanical efficiency increases.

Heat for igniting the fuel oil in the cylinder of a diesel engine is generated by the__________.A electronic ignition systemB compression of air by the pistonC friction in the fuel injector

D fuel oil heating system

A diesel engine crankcase ventilation system __________.A prevents spark generationB removes combustible gasesC determines the level of combustible gasesD provides inert gas generation in crankcaseA 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 causeis __________.

A engine overloadB leaky valvesC stuck or broken piston ringsD low air injection pressure

Piston area, multiplied by piston stroke, multiplied by number of cylinders, equals engine__________.A brake horsepowerB displacementC cylinder volume

D cylinder clearance

The function of the piston compression rings used in a diesel engine is to __________.A seal the space between the piston and linerB transmit heat from the piston to the cylinder linerC reduce the amount of combustion gas blow-byD all of the above

Injection lag in a diesel engine may be caused by __________.

A a higher cetane number of fuel oilB the diesel fuel used having a high viscosity


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C mechanical rigidity in the lube pump mechanismD a decrease in the fuel pump delivery pressure

Which of the combustion parameters listed is used in a diesel engine, but NOT related to theinjection system?

A AtomizationB MeteringC ScavengingD Penetration

Modern marine diesel engines using mechanical fuel injection, operate on a combustioncycle which is __________.A a combination of constant volume and constant pressureB a combination of constant temperature and constant pressureC entirely constant pressure

D entirely constant volume

diesel sorular son

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