C03.
2: Introduction to ICE
OBJECTIES:
Understand Engine Functionality: To grasp how internal combustion engines convert fuel energy into
mechanical energy through combustion and expansion processes.
Differentiate Engine Types: To identify and classify various types of engines based on applications,
design, fuel types, and ignition methods, such as distinguishing between 2-stroke and 4-stroke engines.
Explore Historical Development: To learn about the key milestones and figures in the history of internal
combustion engines, including significant inventions and their impact on engine efficiency and
automotive technology.
Examine Engine Efficiency and Performance: To analyze the factors affecting engine performance, such as
power output, efficiency, and emissions, and how these relate to engine design and operational
principles.
Recognize Environmental Impact: To acknowledge the environmental challenges associated with internal
combustion engines, including emissions regulations and the shift toward sustainable transportation
solutions.
SUMMARY
Engine classifications categorize engines based on design, fuel type, and operational principles. The two
main types are internal combustion engines (ICE) and external combustion engines (ECE). ICEs, like
gasoline and diesel engines, generate power by igniting fuel within the engine cylinders, making them
common in automobiles and machinery. In contrast, ECEs, such as steam engines, use external heat
sources to produce steam, which powers the engine.
Engines are also classified by their cycle of operation. Two-stroke engines complete a power cycle in two
piston strokes, making them simpler and lighter but less efficient. Four-stroke engines, with a more
complex cycle, provide greater efficiency and power output. Fuel type further distinguishes engines, with
options such as gasoline, diesel, electric, and alternative fuels like biofuels and hydrogen.
Historically, key developments in ICE technology include Jean J. Lenoir’s early engine in 1860 and Rudolf
Diesel’s compression ignition engine in 1892. These innovations improved engine efficiency and shaped
modern transportation. Engine performance metrics, including power, efficiency, and emissions, play a
vital role in engine design. Environmental concerns and emissions regulations are driving advancements
in sustainable transportation solutions, emphasizing the need for more efficient and cleaner engine
technologies.
GLOSSARY
1. Active Suspension: A suspension system that adjusts in real-time to driving conditions.
2. Adaptive Cruise Control: Automated system that adjusts vehicle speed to maintain a safe distance
from the vehicle ahead..
3. Aftercooler: A heat exchanger that cools the compressed air from a turbocharger.
4. Air Brake: A brake system that uses compressed air to apply the brakes.
5. Air Conditioning Compressor: A device that compresses refrigerant in the air conditioning system.
6. Alcohol: Alternative fuel derived from plants or synthetics.
7. Anti-lock Braking System (ABS): A system that prevents wheel lock-up during braking.
8. Battery Electric Vehicle (BEV): Vehicle powered entirely by electricity stored in batteries.
9. Battery Pack: Collection of batteries that store electrical energy for hybrid or electric vehicles.
10. Belt Tensioner: A device that maintains tension on the engine drive belts.
11. Biodiesel: Renewable fuel made from biological sources like vegetable oils.
12. Camber: The angle of a wheel relative to vertical, affecting handling and tire wear.
13. Camshaft: A shaft in an engine that controls the opening and closing of valves.
14. Catalytic Converter Efficiency: The effectiveness of a catalytic converter in reducing harmful
emissions.
15. Catalytic Converter: A device in the exhaust system that reduces emissions.
16. Clutch: Device that engages or disengages the engine from the transmission.
17. CNG (Compressed Natural Gas): Natural gas compressed for use as a vehicle fuel.
18. Collision Coverage: Insurance that covers damage to a vehicle from a collision.
19. Compression Ignition: The process by which diesel engines ignite the fuel using heat from
compression.
20. Compression Ratio: Ratio of the volume of the cylinder at bottom dead center to the volume at top
dead center.
21. Compression Stroke: The phase in the engine cycle where the piston compresses the air-fuel
mixture.
22. Congestion: Overcrowding of vehicles on roadways leading to slower movement.
23. Connecting Rod: A component that connects the piston to the crankshaft.
24. Crankshaft Position Sensor: A sensor that monitors the position of the crankshaft for timing
purposes.
25. Crash Test: Evaluation of vehicle safety through simulated collisions.
26. Cylinder Block: The main part of the engine where the cylinders are located.
27. Cylinder Head Gasket: A gasket that seals the cylinder head to the engine block.
28. Cylinder Head: A cover that closes off the top of the engine cylinders, often containing the valves.
29. Diesel Combustion Cycle: The process by which diesel fuel is burned in an engine to create power.
30. Diesel Engine: An internal combustion engine that operates using diesel fuel, known for higher fuel
efficiency and torque.
31. Diesel Particulate Filter (DPF): A filter that removes particulate matter from diesel engine exhaust.
32. Differential: Gear system that allows for differences in wheel speed between the left and right
wheels.
33. Disc Brake: Brake system that uses friction between a disc and brake pads to slow down the vehicle.
34. Drive Shaft: A rotating shaft that transmits torque from the engine to the wheels.
35. Drivetrain: The system of components that delivers power from the engine to the wheels.
36. Drum Brake: A type of brake that uses friction against a drum to slow down a vehicle.
37. Dual-Clutch Transmission (DCT): A transmission that uses two clutches to improve shifting speed.
38. Dynamic Compression Ratio: The compression ratio of an engine while it is operating, as opposed to
the static ratio.
39. Electric Engine: An engine that converts electrical energy into mechanical energy, often used in
electric vehicles.
40. Electric Motor: A device that converts electrical energy into mechanical energy.
41. Engine Control Unit (ECU): Computer that manages engine performance and operation.
42. Engine Mount: A device that secures the engine to the vehicle while dampening vibrations.
43. Engine: A machine designed to convert energy into mechanical power.
44. Ethanol: Alcohol used as a fuel additive made from fermenting plant materials.
45. Evaporative Emission Control System (EVAP): A system that prevents fuel vapor emissions from the
fuel system.
46. Exhaust Backpressure: The pressure exerted by exhaust gases in the exhaust system.
47. Exhaust Manifold: A system that collects exhaust gases from the engine and directs them to the
exhaust system.
48. Feeding System: The system that supplies fuel to the engine.
49. Firing Order: The sequence in which the engine's cylinders fire.
50. Flywheel: A rotating device that helps smooth out engine power delivery.
51. Fossil Fuels: Natural fuels formed from the remains of living organisms, e.g., coal, oil, natural gas.
52. Four-Stroke Engine: Engine that completes a power cycle in four strokes of the piston.
53. Friction Material: A material used in brakes or clutches that provides the necessary friction.
54. Fuel Cell Electric Vehicle (FCEV): Vehicle that uses hydrogen fuel cells to generate electricity.
55. Gasket: Seal that prevents leaks between engine components.
56. Gasoline Engine: A type of internal combustion engine that uses gasoline as fuel, commonly found
in automobiles.
57. Gasoline: Common fuel used in spark-ignited engines.
58. Green Technology: Environmentally friendly technologies aimed at reducing pollution.
59. Head Gasket: A seal between the engine block and cylinder head.
60. Heat Exchanger: A device that transfers heat from one fluid to another.
61. Hybrid Engine: An engine system that combines an internal combustion engine with an electric
motor to improve efficiency.
62. Ignition Coil: A component that converts low-voltage electricity into high-voltage electricity for the
spark plugs.
63. In-line Engine: An engine with all its cylinders arranged in a straight line.
64. Internal Combustion Engine (ICE): An engine that generates power by burning fuel within the engine
cylinders.
65. Lambda Sensor: Another term for an oxygen sensor; measures air-fuel mixture.
66. Lean Mixture: Air-fuel mixture with excess air.
67. Life Cycle Assessment (LCA): Process of evaluating the environmental impacts of a product
throughout its life cycle.
68. Lifting Eye: A point on an engine or other component used for lifting during installation or removal.
69. Limited-Slip Differential: A differential that limits the amount of torque sent to a slipping wheel.
70. LNG (Liquefied Natural Gas): Natural gas cooled to a liquid state for storage and transport.
71. Manual Transmission: A transmission that requires the driver to manually shift gears.
72. Mass Air Flow Sensor (MAF): Sensor that measures the amount of air entering the engine.
73. Muffler: A device that reduces the noise of the exhaust system.
74. Multivalve Engine: An engine with more than two valves per cylinder.
75. Natural Gas: Cleaner-burning fossil fuel used in some engines.
76. Naturally Aspirated: Engine that draws air through atmospheric pressure alone.
77. Noise Pollution: Excessive or harmful levels of noise in the environment, often caused by traffic and
engines.
78. Octane Rating: Measure of a fuel's resistance to knocking.
79. Oil Filter: A filter that removes impurities from engine oil.
80. Oil Pump: Device that circulates oil throughout the engine for lubrication.
81. Opposed-Piston Engine: Engine with pistons that move towards each other.
82. Overhead Camshaft (OHC): A camshaft located above the engine's cylinders.
83. Overhead Valve (OHV): An engine with valves located in the
84. Piston Ring: A ring that seals the gap between the piston and the cylinder wall.
85. Piston Travel: The distance a piston moves within a cylinder.
86. Power Curve: Graph showing how power varies with engine speed.
87. Power Output: The amount of work an engine can perform over time, usually measured in
horsepower or kilowatts.
88. Power Stroke: Stroke in which combustion occurs and power is produced.
89. Pushrod Engine: An engine with valves operated by pushrods and rockers, usually with the camshaft
in the engine block.
90. Radial Engine: Engine design where cylinders radiate from a central crankshaft.
91. Radiator Cap: A cap that maintains pressure in the cooling system.
92. Radiator Fan: A fan that cools the engine coolant as it passes through the radiator.
93. Remote Start: A system that allows the engine to be started from a distance.
94. Rich Mixture: Air-fuel mixture with excess fuel.
95. Rotary Engine: An engine that uses a rotating triangular rotor instead of pistons.
96. Safety Valve: A valve that releases pressure to prevent system failure.
97. Sealing Gasket: A gasket that prevents leakage between engine components.
98. Shock Absorber: A device that dampens the movement of a vehicle's suspension.
99. Shock Load: A sudden application of load, which can impact engine and component integrity.
100. Skid Control: Techniques used to maintain vehicle stability during sliding.
101. Smart Grid: Modernized electrical grid that uses technology for efficient energy distribution.
102. Spark Plug: A device that ignites the air-fuel mixture in an internal combustion engine.
103. Speedometer: A device that measures and displays the vehicle's speed.
104. Stability Control: A system that helps maintain vehicle stability during extreme maneuvers.
105. Synthetic Fuels: Fuels produced from non-petroleum sources, often through chemical processes.
106. Telematics: Technology that integrates telecommunications and monitoring systems in vehicles.
107. Thermostat: A device that regulates the engine's temperature by controlling coolant flow.
108. Throttle: A device that controls the flow of air into the engine.
109. Timing Belt: A belt that synchronizes the movement of the camshaft and crankshaft.
110. Tire Pressure: Inflation level of a tire, affecting safety and performance.
111. Turbo-Compound: Engine that uses exhaust gases to power a turbine for added efficiency.
112. Two-Stroke Engine: An engine that completes a power cycle in two strokes of the piston, resulting in
a simpler design.
113. V8 Engine: An engine with eight cylinders arranged in a V shape.
114. Vacuum Advance: A mechanism that adjusts the ignition timing based on engine load.
115. V-belt: A type of belt used to drive engine accessories, known for its trapezoidal cross-section.
116. V-Block Engine: Engine design with cylinders arranged in a V shape.
117. Wastegate: A valve that controls the flow of exhaust gases to the turbocharger.
118. Water Pump: A pump that circulates coolant through the engine.
119. Wear Ring: A component that prevents wear on the engine's moving parts.
120. Wheel Alignment: The adjustment of a vehicle's suspension components to ensure proper wheel
orientation.
121. Wheel Slip: The difference between the speed of the wheels and the speed of the vehicle.
122. Wheelbase: The distance between the front and rear wheels of a vehicle.
123. Wrist Pin: A pin that connects the piston to the connecting rod.
124. X-axis: In vehicle dynamics, the axis along the length of the vehicle.
125. Y-axis: The lateral (side-to-side) axis in vehicle dynamics.
126. Z-axis: The vertical axis in vehicle dynamics.
What is an internal combustion engine?
A) A device that converts fuel energy into thermal energy
B) A device that converts fuel energy into mechanical energy
C) A device that operates on renewable energy
D) A device that does not require fuel
Answer: B) A device that converts fuel energy into mechanical energy
What distinguishes a two-stroke engine from a four-stroke engine?
A) Fuel type
B) Number of revolutions to complete a power cycle
C) Cylinder design
D) Size of the engine
Answer: B) Number of revolutions to complete a power cycle
What is the purpose of the compression ratio in an engine?
A) To measure fuel consumption
B) To determine engine size
C) To indicate the efficiency of combustion
D) To assess the weight of the engine
Answer: C) To indicate the efficiency of combustion
Define "thermal efficiency" in an internal combustion engine.
A) Ratio of fuel consumption to power output
B) Ratio of work output to heat input from fuel
C) Ratio of engine size to power output
D) Ratio of exhaust emissions to fuel used
Answer: B) Ratio of work output to heat input from fuel
What is the role of a spark plug in a gasoline engine?
A) To compress the fuel-air mixture
B) To ignite the air-fuel mixture
C) To cool the engine
D) To filter the exhaust gases
Answer: B) To ignite the air-fuel mixture
Which of the following is a characteristic of diesel engines?
A) Use spark ignition
B) Use compression ignition
C) Operate at higher RPMs than gasoline engines
D) Use a carburetor for fuel mixing
Answer: B) Use compression ignition
What is a "reciprocating engine"?
A) An engine with rotating components
B) An engine where pistons move back and forth
C) An engine powered by external combustion
D) An engine that uses solar energy
Answer: B) An engine where pistons move back and forth
Which type of fuel is commonly used in internal combustion engines?
A) Hydrogen
B) Gasoline
C) Solar energy
D) Wind energy
Answer: B) Gasoline
What does "open cycle" refer to in engine operation?
A) Working fluid is recycled within the engine
B) Working fluid is discharged to the atmosphere
C) Combustion occurs outside the engine
D) Engine uses renewable energy
Answer: B) Working fluid is discharged to the atmosphere
What is one advantage of a turbocharger?
A) Reduces engine weight
B) Increases engine power output
C) Lowers fuel consumption
D) Eliminates exhaust emissions
Answer: B) Increases engine power output
Problems
What type of engine uses a reciprocating design?
A) Rotary Engine
B) Diesel Engine
C) Gas Turbine
D) Jet Engine
Answer: B) Diesel Engine
Explanation: Diesel engines typically use a reciprocating design with pistons moving in cylinders.
Which of the following is a characteristic of a four-stroke engine?
A) Completes a power cycle in two strokes
B) Combustion occurs on every crankshaft revolution
C) Requires four strokes to complete one power cycle
D) More fuel-efficient than two-stroke engines
Answer: C) Requires four strokes to complete one power cycle
Explanation: Four-stroke engines require intake, compression, power, and exhaust strokes to complete a
cycle.
What type of ignition does a gasoline engine typically use?
A) Compression Ignition
B) Spark Ignition
C) Thermal Ignition
D) Photo Ignition
Answer: B) Spark Ignition
Explanation: Gasoline engines use spark plugs to ignite the fuel-air mixture, known as spark ignition.
Which of the following fuels is commonly used in compression ignition engines?
A) Gasoline
B) Natural Gas
C) Diesel
D) Alcohol
Answer: C) Diesel
Explanation: Compression ignition engines primarily use diesel fuel due to its higher energy density and
ignition properties.
What is a key advantage of two-stroke engines over four-stroke engines?
A) Higher fuel efficiency
B) Simplicity in design
C) Lower power-to-weight ratio
D) Longer operational life
Answer: B) Simplicity in design
Explanation: Two-stroke engines have fewer moving parts, making them simpler and often lighter than
four-stroke engines.
Which engine type is commonly used in motorcycles?
A) Diesel Engine
B) Two-Stroke Engine
C) Stirling Engine
D) Wankel Engine
Answer: B) Two-Stroke Engine
Explanation: Two-stroke engines are popular in motorcycles due to their power-to-weight ratio and
compact size.
What is a significant disadvantage of using leaded gasoline?
A) Increased fuel efficiency
B) Higher octane rating
C) Environmental pollution
D) Lower engine temperature
Answer: C) Environmental pollution
Explanation: Leaded gasoline contributes to air pollution and has been phased out in many regions due
to its environmental impact.
Which type of engine uses a rotary design?
A) Diesel Engine
B) Wankel Engine
C) Steam Engine
D) Four-Stroke Engine
Answer: B) Wankel Engine
Explanation: The Wankel engine uses a rotary design, which is distinct from traditional reciprocating
engines.
What does the term "thermal efficiency" refer to in engines?
A) The amount of heat lost during operation
B) The ratio of work output to heat input
C) The amount of fuel consumed
D) The engine's maximum temperature
Answer: B) The ratio of work output to heat input
Explanation: Thermal efficiency measures how effectively an engine converts heat energy into work.
Which engine type is often used in power generation applications?
A) Two-Stroke Engine
B) Diesel Engine
C) Wankel Engine
D) Stirling Engine
Answer: B) Diesel Engine
Explanation: Diesel engines are widely used for power generation due to their durability and fuel
efficiency.
What is a major benefit of turbocharging an engine?
A) Decreased fuel consumption
B) Increased power output
C) Simplicity in design
D) Lower emissions
Answer: B) Increased power output
Explanation: Turbocharging increases the engine's air intake, resulting in more power output without
significantly increasing engine size.
Which type of engine operates on the principle of the Otto cycle?
A) Diesel Engine
B) Wankel Engine
C) Gasoline Engine
D) Steam Engine
Answer: C) Gasoline Engine
Explanation: Gasoline engines typically operate on the Otto cycle, involving compression and ignition
through spark.
What is the main function of a fuel injection system?
A) To store fuel
B) To mix air and fuel
C) To vaporize fuel
D) To deliver fuel to the combustion chamber
Answer: D) To deliver fuel to the combustion chamber
Explanation: The fuel injection system is responsible for delivering the precise amount of fuel to the
combustion chamber.
Which of the following engines is known for its high power density?
A) Four-Stroke Engine
B) Two-Stroke Engine
C) Diesel Engine
D) Rotary Engine
Answer: B) Two-Stroke Engine
Explanation: Two-stroke engines are known for their high power density due to their ability to produce
power every revolution of the crankshaft.
What is a primary characteristic of a closed-cycle engine?
A) Working fluid is expelled after use
B) Working fluid is recycled through the system
C) Combustion occurs outside the engine
D) Uses steam as a working fluid
Answer: B) Working fluid is recycled through the system
Explanation: Closed-cycle engines recycle the working fluid, which is more efficient than expelling it.
Which engine type is primarily used in heavy-duty vehicles?
A) Gasoline Engine
B) Two-Stroke Engine
C) Diesel Engine
D) Stirling Engine
Answer: C) Diesel Engine
Explanation: Diesel engines are preferred for heavy-duty vehicles due to their torque and fuel efficiency.
What does the term "compression ratio" refer to in engines?
A) The ratio of fuel to air mixture
B) The volume of the combustion chamber at its largest to its smallest
C) The ratio of power output to fuel consumed
D) The engine's maximum temperature
Answer: B) The volume of the combustion chamber at its largest to its smallest
Explanation: Compression ratio is a critical parameter affecting engine performance and efficiency.
Which of the following types of engines is more suitable for high-speed applications?
A) Diesel Engine
B) Two-Stroke Engine
C) Wankel Engine
D) Stirling Engine
Answer: C) Wankel Engine
Explanation: The Wankel engine's rotary design allows for high-speed operation compared to traditional
engines.
What type of fuel is primarily used in rotary engines?
A) Diesel
B) Gasoline
C) Natural Gas
D) Alcohol
Answer: B) Gasoline
Explanation: Rotary engines, like the Wankel, primarily use gasoline as fuel due to their combustion
characteristics.
What is the main advantage of a hybrid engine?
A) Lower initial cost
B) Increased fuel efficiency
C) Higher emissions
D) Simplicity in design
Answer: B) Increased fuel efficiency
REFERENCES
Heywood, J. B. (1988). Internal Combustion Engine Fundamentals. New York: McGraw-
Hill.
Stone, R. (1999). Introduction to Internal Combustion Engines. New York: Palgrave
Macmillan.
Ganesan, V. (2007). Internal Combustion Engines. New Delhi: Tata McGraw-Hill
Education.
Kuo, S. (2010). Thermal Sciences: An Introduction to Thermodynamics, Fluid Mechanics,
and Heat Transfer. New York: Wiley.
M. S. (2020). Engine Testing: Theory and Practice. New York: Wiley.
