Question 1

Two technicians are discussing combustion slobber. Technician A says that low piston temperatures also mean the piston has not fully expanded and will easily allow lube oil into the combustion chamber. Technician B says that the black gooey liquid that leaks from exhaust manifold joints and the exhaust pipes when engines are excessively idled is called sludge. Who is right?

Accepted Answer

A)  A only"
B)  B only"
C)  Both A and B
D)  Neither A nor B" A

Question 2

Which of the following diesel engine combustion chambers requires a glow plug to start?

Accepted Answer

A)  Direct injection.
B)  Indirect injection.
C)  Hemispheric chamber.
D)  Turbulence chamber. B

Question 3

Technician A says that diesel engines supply only enough air to completely burn all the fuel in the combustion chamber. Technician B says that diesel engines supply excess air to the combustion chamber to completely burn all the fuel in the combustion chamber. Who is correct?

Accepted Answer

A)  Technician A
B)  Technician B
C)  Both A and B
D)  Neither A nor B B

Question 4

Once the engine is operational, the controller will cycle the plugs on and off during the ________ period.

Accepted Answer

A)  afterglow"
B)  pre-glow"
C)  heating
D)  warm-up"

Question 5

The IDI combustion system uses fuel injected into a smaller, spherical, highly turbulent chamber that is connected to a main chamber through a narrow passageway called a(n):

Accepted Answer

A)  venturi"
B)  orifice"
C)  nozzle
D)  port"

Question 6

At what level of efficiency did Rudolf Diesel's slow-rotating engine operate?

Accepted Answer

A)  25%"
B)  50%"
C)  75%
D)  100%"

Question 7

At which of the following compression ratios does the efficiency of an engine begin to diminish with increasing compression?

Accepted Answer

A)  12:1.
B)  16:1.
C)  23:1.
D)  25:1.

Question 8

Smaller four-stroke diesels require a minimum cranking speed of ______ rpm to start.

Accepted Answer

A)  150"
B)  180"
C)  125
D)  135"

Question 9

What happens to the coarse fuel droplets when fuel initially contacts the incandescent glow plug during start-up and then on the hot walls of the pre-chamber during regular operation?

Accepted Answer

A)  They vaporize"
B)  They atomize"
C)  They get mixed
D)  They boil"

Question 10

Which of these causes more heat retention by the engine around the exhaust ports, thus transferring more heat to the cooling system?

Accepted Answer

A)  Exhaust backpressure"
B)  Lower temperature thermostat"
C)  Higher temperature thermostat
D)  EGR valve"

Question 11

Technician A says that diesel engines inject liquid fuel under high pressure into the combustion chamber near the end of the intake stroke. Technician B says that air that is heated during the compression stroke becomes the ignition source. Who is right?

Accepted Answer

A)  A only"
B)  B only"
C)  Both A and B
D)  Neither A nor B"

Question 12

Technician A says that some studies suggest that electric vehicles may in fact be dirtier than diesel engines due to battery manufacturing. Technician B says that after including emissions from lithium-ion battery, electric vehicles generate half the emissions of a traditional internal combustion engine. Who is right?

Accepted Answer

A)  A only"
B)  B only"
C)  Both A and B
D)  Neither A nor B"

Question 13

When did Rudolph Diesel (1858-1913) patent his engine?

Accepted Answer

A)  1899"
B)  1892"
C)  1900
D)  1883"

Question 14

Technician A says that a diesel engine's higher compression ratio helps it to produce more power and use less fuel. Technician B says that higher compression ratios only help the diesel engine produce more torque. Who is correct?

Accepted Answer

A)  Technician A"
B)  Technician B"
C)  Both A and B
D)  Neither A nor B"

Question 15

Technician A says that diesel engines inject fuel into the cylinder during the intake stroke. Technician B says that diesel engines inject fuel into the cylinder near the end of the compression stroke. Who is correct?

Accepted Answer

A)  Technician A
B)  Technician B
C)  Both A and B
D)  Neither A nor B

Question 16

Until the development of antiknock additives for gasoline, such as tetraethyl lead in the late 1920s, compression of an air and fuel mixture was limited to the ratio:

Accepted Answer

A)  4:1"
B)  5:1"
C)  6:1
D)  10:1"

Question 17

Technician A says that a diesel engine's higher compression ratio helps it to produce more power and use less fuel. Technician B says that higher compression ratios only help the diesel engine produce more torque. Who is correct?

Accepted Answer

A)  Technician A
B)  Technician B
C)  Both A and B
D)  Neither A nor B

Question 18

After which 20th Century event did the thriftier diesel become regarded as a potential replacement for gasoline engines?

Accepted Answer

A)  1970: oil crisis in North America"
B)  1960s: creation of OPEC"
C)  1930s: development of compact fuel-injection equipment
D)  2008: financial crisis in North America"

Question 19

The diesel engine produces significantly higher _______ compared to similarly displaced gasoline-fueled engines.

Accepted Answer

A)  horsepower"
B)  torque"
C)  emissions
D)  speed"

Question 20

There are _____ basic combustion chamber diesel engine designs but numerous variations on both.

Accepted Answer

A)  1"
B)  2"
C)  3
D)  4"

Exam 2: Introduction to Diesel Engines

Which of the following diesel engine combustion chambers requires a glow plug to start?

Technician A says that diesel engines supply only enough air to completely burn all the fuel in the combustion chamber. Technician B says that diesel engines supply excess air to the combustion chamber to completely burn all the fuel in the combustion chamber. Who is correct?

Once the engine is operational, the controller will cycle the plugs on and off during the ________ period.

The IDI combustion system uses fuel injected into a smaller, spherical, highly turbulent chamber that is connected to a main chamber through a narrow passageway called a(n) :

At what level of efficiency did Rudolf Diesel's slow-rotating engine operate?

At which of the following compression ratios does the efficiency of an engine begin to diminish with increasing compression?

Smaller four-stroke diesels require a minimum cranking speed of ______ rpm to start.

What happens to the coarse fuel droplets when fuel initially contacts the incandescent glow plug during start-up and then on the hot walls of the pre-chamber during regular operation?

Which of these causes more heat retention by the engine around the exhaust ports, thus transferring more heat to the cooling system?

Technician A says that diesel engines inject liquid fuel under high pressure into the combustion chamber near the end of the intake stroke. Technician B says that air that is heated during the compression stroke becomes the ignition source. Who is right?

When did Rudolph Diesel (1858-1913) patent his engine?

Technician A says that a diesel engine's higher compression ratio helps it to produce more power and use less fuel. Technician B says that higher compression ratios only help the diesel engine produce more torque. Who is correct?

Technician A says that diesel engines inject fuel into the cylinder during the intake stroke. Technician B says that diesel engines inject fuel into the cylinder near the end of the compression stroke. Who is correct?

Until the development of antiknock additives for gasoline, such as tetraethyl lead in the late 1920s, compression of an air and fuel mixture was limited to the ratio:

Technician A says that a diesel engine's higher compression ratio helps it to produce more power and use less fuel. Technician B says that higher compression ratios only help the diesel engine produce more torque. Who is correct?

After which 20^th Century event did the thriftier diesel become regarded as a potential replacement for gasoline engines?

The diesel engine produces significantly higher _______ compared to similarly displaced gasoline-fueled engines.

There are _____ basic combustion chamber diesel engine designs but numerous variations on both.