Components of an Internal Combustion Engine

An internal combustion engine is the most popular type of vehicle engine, which ignites fossil fuel and uses the resulting explosion to generate movement. The engine is comprised of several components which perform together to achieve the unified functionality of the vehicle being able to move or kinetic energy being created from the chemical energy stored in fossil fuel. Internal combustion engines can be identified to be of two types – spark ignition engine and compression ignition engine. The former ignites the fuel (usually petrol/gasoline) with an electric spark from the vehicle’s battery while the latter uses the pressure and heat generated by compressing the fuel (usually diesel) to ignite it. The working principles of both types of engines are virtually identical aside from the method of ignition. This article describes several components found in an internal combustion engine along with their functionality.

Fuel Injector

Fuel injectors are used to inject fuel into the combustion chamber of an engine. The combustion chamber is filled with air (containing oxygen required for the explosion) and fuel and is ignited by one of the methods described above. The injector delivers the fuel to the chamber at the appropriate volume, time intervals, pressure, and angles to efficiently burn the fuel and release its energy. A fuel pump may be used to transfer fuel from the tank to the injector at the required pressure. Aftermarket pumps can be purchased from providers such as fuel pumps for sale that allow for custom pressure configurations to maximise fuel efficiency or performance.

Cylinder Block

A cylinder is the housing which contains the piston and the combustion chamber. A cylinder block houses several pistons with its combustion chamber which ignite in tandem to produce a greater amount of kinetic energy. It is in direct contact with the exploding fuels and requires cooling, which is generally carried out by the engine cooling system by transferring heat via a coolant oil. It should also be strong enough to withstand the force of the explosion and piston movements as well as be relatively lightweight to not hinder the efficiency or waste energy.


A piston of an engine is the primary moving part. It absorbs the energy of the combustion reaction and movies along the housing, while attached to the connecting rod to transfer kinetic energy via thrust. The piston should be sufficiently strong as to handle the strength of the explosion without damaging itself or the housing while being lightweight enough to transfer a larger portion of the generated energy. Pistons are generally made of aluminium alloy or cast iron.

Connecting Rod

The connecting rod connects the piston to the crankshaft and transmits the thrusting motion of the piston onto the crankshaft, which rotates. The rod then pushes the piston back into the original position to begin the next engine cycle.


The crankshaft is the primary rotating element of the engine, and collects the kinetic energy received through the pistons from the connecting rod. The crankshaft uses this energy to rotate and create usable motion for the vehicle.