Question 1

Which of the following is NOT provided by a higher compression ratio?

Accepted Answer

A) Higher expansion ratios" 
B) Improved combustion" 
C) Better air-fuel mixture 
D) Lower expansion ratios" 
A) Higher expansion ratios" 
B) Improved combustion" 
C) Better air-fuel mixture 
D) Lower expansion ratios"

Question 2

Engine efficiency drops after a compression ratio of:

Accepted Answer

A) 21:1" 
B) 23:1" 
C) 25:1 
D) 27:1" 
A) 21:1" 
B) 23:1" 
C) 25:1 
D) 27:1"

Question 3

Which combustion chamber design produces the best fuel economy in a diesel engine?

Accepted Answer

A) Direct injection. 
B) Indirect injection. 
C) Swirl chamber. 
D) Wedge chamber. 
A) Direct injection. 
B) Indirect injection. 
C) Swirl chamber. 
D) Wedge chamber.

Question 4

DI chambers generally require no:

Accepted Answer

A) EGR valves" 
B) particulate filters" 
C) oxidation catalysts 
D) starting aids" 
A) EGR valves" 
B) particulate filters" 
C) oxidation catalysts 
D) starting aids"

Question 5

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

Question 6

Which type of fuel nozzle is used in a direct-injection combustion chamber?

Accepted Answer

A) Multi-orifice nozzle. 
B) Pintle-type nozzle. 
C) Closed nozzle. 
D) Open nozzle. 
A) Multi-orifice nozzle. 
B) Pintle-type nozzle. 
C) Closed nozzle. 
D) Open nozzle.

Question 7

Which of the following best describes the term "ignition delay"?

Accepted Answer

A) The time required to raise the fuel pressure high enough to overcome compression pressure in a cylinder." 
B) The time lag from initial injection to actual ignition." 
C) The time required to heat up a glow plug. 
D) The time required for vaporized fuel to atomize." 
A) The time required to raise the fuel pressure high enough to overcome compression pressure in a cylinder." 
B) The time lag from initial injection to actual ignition." 
C) The time required to heat up a glow plug. 
D) The time required for vaporized fuel to atomize."

Question 8

Typically, diesel engines will achieve between _____ better fuel economy in comparison to similar gasoline engines.

Accepted Answer

A) 15% and 40%" 
B) 25% and 70%" 
C) 25% and 60% 
D) 45% and 90%" 
A) 15% and 40%" 
B) 25% and 70%" 
C) 25% and 60% 
D) 45% and 90%"

Question 9

In comparison to electric vehicles, a recent study by Energy and Environment Study Institute determined the battery electric models offered for sale in the US have an average base price of $63,000 and an average driving range of:

Accepted Answer

A) 111 miles" 
B) 211 miles" 
C) 311 miles 
D) 411 miles" 
A) 111 miles" 
B) 211 miles" 
C) 311 miles 
D) 411 miles"

Question 10

Compression pressures produce an average pre-ignition temperature of:

Accepted Answer

A) 1,000°F 
B) 2000°F" 
C) 3,000°F 
D) 4000°F" 
A) 1,000°F 
B) 2000°F" 
C) 3,000°F 
D) 4000°F"

Question 11

What creates low exhaust temperatures and low cylinder temperatures, which have adverse consequences on engine life and operation?

Accepted Answer

A) High thermostat" 
B) Excess air" 
C) Excess fuel 
D) Exhaust backpressure" 
A) High thermostat" 
B) Excess air" 
C) Excess fuel 
D) Exhaust backpressure"

Question 12

Technician A says that injection quantities of fuel in a diesel engine at idle are very large. Technician B says that the cooling effect of excess air and prolonged idle has detrimental effects on the engine. Who is right?

Accepted Answer

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

Question 13

Technician A says that small quantities of diesel fuel are adequate to create enough cylinder pressure to rotate the crankshaft but produce very little heat. Technician B says that less air in diesels dilutes the heat of combustion and lowers average cylinder temperatures. Who is right?

Accepted Answer

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

Question 14

Which one of the following is NOT a reason for the IDI chamber being the most popular design in automotive applications in the early 1990s?

Accepted Answer

A) High-speed capabilities" 
B) Favorable emissions characteristics" 
C) Inexpensive fuel-injection systems 
D) 10-15% greater fuel efficiency" 
A) High-speed capabilities" 
B) Favorable emissions characteristics" 
C) Inexpensive fuel-injection systems 
D) 10-15% greater fuel efficiency"

Question 15

How many valves will most likely be used by a centrally located fuel injector?

Accepted Answer

A) Two valves per cylinder. 
B) Three valves per cylinder. 
C) Four valves per cylinder. 
D) Any number of valves. 
A) Two valves per cylinder. 
B) Three valves per cylinder. 
C) Four valves per cylinder. 
D) Any number of valves.

Question 16

Identify the points on the PV (pressure volume) graph between which uncontrolled burn period occurs.

Accepted Answer

A) A and B" 
B) B and C" 
C) C and D 
D) D and E" 
A) A and B" 
B) B and C" 
C) C and D 
D) D and E"

Question 17

In 1929, Clessie Cummins, founder of Cummins Engine Company, built North America's first diesel-powered:

Accepted Answer

A) car" 
B) truck" 
C) boat 
D) tractor" 
A) car" 
B) truck" 
C) boat 
D) tractor"

Question 18

Which one of the following conditions will be produced by prolonged ignition delay in a diesel engine?

Accepted Answer

A) An engine knocking sound." 
B) Blue smoke." 
C) White smoke. 
D) Lower peak cylinder pressures." 
A) An engine knocking sound." 
B) Blue smoke." 
C) White smoke. 
D) Lower peak cylinder pressures."

Question 19

Which combustion chamber design has traditionally operated with the least amount of noise?

Accepted Answer

A) Direct injection. 
B) Indirect injection. 
C) Two stroke. 
D) Penta chamber. 
A) Direct injection. 
B) Indirect injection. 
C) Two stroke. 
D) Penta chamber.

Question 20

While diesel engines do not have compression limits to combustion, compression ratios above what ratio provide minimal power increases?

Accepted Answer

A) 12:1" 
B) 14:1" 
C) 15:1 
D) 16:1" 
A) 12:1" 
B) 14:1" 
C) 15:1 
D) 16:1"

Which of the following is NOT provided by a higher compression ratio?

Engine efficiency drops after a compression ratio of:

Which combustion chamber design produces the best fuel economy in a diesel engine?

DI chambers generally require no:

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?

Which type of fuel nozzle is used in a direct-injection combustion chamber?

Which of the following best describes the term "ignition delay"?

Typically, diesel engines will achieve between _____ better fuel economy in comparison to similar gasoline engines.

In comparison to electric vehicles, a recent study by Energy and Environment Study Institute determined the battery electric models offered for sale in the US have an average base price of $63,000 and an average driving range of:

Compression pressures produce an average pre-ignition temperature of:

What creates low exhaust temperatures and low cylinder temperatures, which have adverse consequences on engine life and operation?

Technician A says that injection quantities of fuel in a diesel engine at idle are very large. Technician B says that the cooling effect of excess air and prolonged idle has detrimental effects on the engine. Who is right?

Technician A says that small quantities of diesel fuel are adequate to create enough cylinder pressure to rotate the crankshaft but produce very little heat. Technician B says that less air in diesels dilutes the heat of combustion and lowers average cylinder temperatures. Who is right?

Which one of the following is NOT a reason for the IDI chamber being the most popular design in automotive applications in the early 1990s?

How many valves will most likely be used by a centrally located fuel injector?

Identify the points on the PV (pressure volume) graph between which uncontrolled burn period occurs.

In 1929, Clessie Cummins, founder of Cummins Engine Company, built North America's first diesel-powered:

Which one of the following conditions will be produced by prolonged ignition delay in a diesel engine?

Which combustion chamber design has traditionally operated with the least amount of noise?

While diesel engines do not have compression limits to combustion, compression ratios above what ratio provide minimal power increases?

Diesel Engine Emissions

Cylinder Blocks and Crankshafts

Cylinder Components

Cylinder Heads and Valve Train Mechanisms

Diesel Engine Cooling and Lubrication Systems

Diesel Fuel and Low Pressure Fuel Systems

Functions of High Pressure Fuel Systems

Governors and Electronic Control Systems

Hydraulic Nozzles

Heui Injection Systems

Common Rail Fuel Systems

Air Induction and Crankcase Ventilation Systems

Fixed Geometry and Wastegated Turbochargers

Variable Geometry and Series Turbochargers

Exhaust Gas Recirculation

Exhaust Aftertreatment Systems

On Board Diagnostics

Filters

Exam 2: Introduction to Diesel Engines

Which of the following is NOT provided by a higher compression ratio?

Engine efficiency drops after a compression ratio of:

Which combustion chamber design produces the best fuel economy in a diesel engine?

DI chambers generally require no:

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?

Which type of fuel nozzle is used in a direct-injection combustion chamber?

Which of the following best describes the term "ignition delay"?

Typically, diesel engines will achieve between _____ better fuel economy in comparison to similar gasoline engines.

In comparison to electric vehicles, a recent study by Energy and Environment Study Institute determined the battery electric models offered for sale in the US have an average base price of $63,000 and an average driving range of:

Compression pressures produce an average pre-ignition temperature of:

What creates low exhaust temperatures and low cylinder temperatures, which have adverse consequences on engine life and operation?

Technician A says that injection quantities of fuel in a diesel engine at idle are very large. Technician B says that the cooling effect of excess air and prolonged idle has detrimental effects on the engine. Who is right?

Technician A says that small quantities of diesel fuel are adequate to create enough cylinder pressure to rotate the crankshaft but produce very little heat. Technician B says that less air in diesels dilutes the heat of combustion and lowers average cylinder temperatures. Who is right?

Which one of the following is NOT a reason for the IDI chamber being the most popular design in automotive applications in the early 1990s?

How many valves will most likely be used by a centrally located fuel injector?

Identify the points on the PV (pressure volume) graph between which uncontrolled burn period occurs.

In 1929, Clessie Cummins, founder of Cummins Engine Company, built North America's first diesel-powered:

Which one of the following conditions will be produced by prolonged ignition delay in a diesel engine?

Which combustion chamber design has traditionally operated with the least amount of noise?

While diesel engines do not have compression limits to combustion, compression ratios above what ratio provide minimal power increases?

Diesel Engine Emissions

Cylinder Blocks and Crankshafts

Cylinder Components

Cylinder Heads and Valve Train Mechanisms

Diesel Engine Cooling and Lubrication Systems

Diesel Fuel and Low Pressure Fuel Systems

Functions of High Pressure Fuel Systems

Governors and Electronic Control Systems

Hydraulic Nozzles

Heui Injection Systems

Common Rail Fuel Systems

Air Induction and Crankcase Ventilation Systems

Fixed Geometry and Wastegated Turbochargers

Variable Geometry and Series Turbochargers

Exhaust Gas Recirculation

Exhaust Aftertreatment Systems

On Board Diagnostics

Filters