Engine system

The engine is the heart of your car. It is a complex machine built to convert heat from burning gas into the force that turns the road wheels.

The chain of reactions which achieve that objective is set in motion by a spark , which ignites a mixture of petrol vapour and compressed air inside a momentarily sealed cylinder and causes it to burn rapidly. That is why the machine is called an internal combustion engine . As the mixture burns it expands, providing power to drive the car.

To withstand its heavy workload, the engine must be a robust structure. It consists of two basic parts: the lower, heavier section is the cylinder block, a casing for the engine's main moving parts; the detachable upper cover is the cylinder head .

The cylinder head contains valve-controlled passages through which the air and fuel mixture enters the cylinders, and others through which the gases produced by their combustion are expelled.

The block houses the crankshaft , which converts the reciprocating motion of the pistons into rotary motion at the crankshaft. Often the block also houses the camshaft , which operates mechanisms that open and close the valves in the cylinder head. Sometimes the camshaft is in the head or mounted above it.