Components of an Internal Combustion (IC) Engine - Part 2

written by: Haresh Khemani • edited by: Swagatam • updated: 12/10/2008

Most of the components of the spark ignition (SI) and compression ignition (CI) engines are the same. The important components of the engine are: cylinder block, cylinders, pistons, connecting rod, crankshaft, crankcase, etc. This is part two describing the important components in IC engines.

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    In the previous part of the article we had seen some important components of the internal combustion (IC) engine. Here are the other remaining parts of the engine.

    4) Piston rings: The piston rings are thin rings fitted in the slots made along the surface of the piston. It provides a tight seal between the piston and the cylinder walls that prevents leaking of the combustion gases from one side to the other. This ensures that that motion of the piston produces as close as to the power generated from inside the cylinder.

    5) Combustion chamber: It is in the combustion chamber where the actual burning of fuel occurs. It is the uppermost portion of the cylinder enclosed by the cylinder head and the piston. When the fuel is burnt, much thermal energy is produced which generates excessively high pressures causing the reciprocating motion of the piston.

    6) Inlet manifold: Through the inlet manifold the air or air-fuel mixture is drawn into the cylinder.

    7) Exhaust manifold: All the exhaust gases generated inside the cylinder after burning of fuel are discharged through the exhaust manifold into the atmosphere.

    8) Inlet and exhaust valves: The inlet and the exhaust valves are placed at the top of the cylinder in the cylinder head. The inlet valves allows the intake of the fuel during suction stroke of the piston and to close thereafter. During the exhaust stroke of the piston the exhaust valves open allowing the exhaust gases to release to the atmosphere. Both these valves allow the flow of fuel and gases in single direction only.

    9) Spark plug: The spark plug is a device that produces a small spark that causes the instant burning of the pressurized fuel.

    10) Connecting rod: It is the connecting link between the piston and the crankshaft that performs the rotary motion. There are two ends of the connecting rod called the small end and big end. The small end of the connecting rod is connected to the piston by gudgeon pin, while the big end is connected to crankshaft by crank pin.

    11) Crankshaft: The crankshaft performs the rotary motion. It is connected to the axle of the wheels which move as the crankshaft rotates. The reciprocating motion of the piston is converted into the rotary motion of the crankshaft with the help of connecting rod. The crankshaft is located in the crankcase and it rotates in the bushings.

    The above are the important components of the IC engines. Automotive companies have mastered the art of manufacturing the precise components of the IC engines; hence engine lifespans have been increasing over the years. Major changes have been carried out in the designing of the engines to  increase their fuel efficiency and the total power output of the vehicle.

    These days the engines are also designed to work on different type of fuels. Thus you can run your vehicle either on gasoline fuel or LPG.

    Part One of the article can be found here:
    Components of an Internal Combustion (IC) Engine - Part 1

Internal Combustion Engine

This is the series of articles on internal combustion engine that describes various parts of the internal combustion engine, also called as IC engine.
  1. Components of an Internal Combustion (IC) Engine - Part 1
  2. Components of an Internal Combustion (IC) Engine - Part 2