Basic mechanics: how does a car engine work?

Can you explain how a car engine works ? How many types of engines are there? They are simple questions whose response is somewhat more complex than it seems. However, through these illustrations you will not have any doubt.

The engine is the heart of every automobile. It is a machine built to convert the heat produced by the explosion (in the case of petrol) or the combustion (in the case of diesel) of the fuel in a movement with enough force for the wheels to turn and the vehicle can travel.

In the case of the conventional gasoline engine, the chain of reactions that reaches that target is set in motion by a spark, which ignites a mixture of fuel vapor and compressed air inside a momentarily sealed cylinder, causing the mixture to burn out quickly . As the mixture burns, it expands and provides energy.

The basic parts of the combustion engine

To support this heavy workload the motor must be sufficiently solid. It consists of two basic parts: the engine block and the cylinder head. The engine block is the lower and heavier part, a housing for the main movement of the engine parts.

The cylinder head can contain the camshaft, which controls which valves (intake and exhaust) must be opened and closed at all times. The intake valves let the air and fuel mixture pass to the cylinders, while the exhaust valves open to release the gases produced after combustion.

The block also houses the crankshaft, which converts the linear and reciprocating movement of the pistons into rotary motion. An oil tank, called a crankcase, is screwed under the crankcase so that, driven by a pump, all the moving parts are perfectly lubricated and the dreaded friction seizure does not occur.

Generally, both the block and the cylinder head are made of cast iron. Although aluminum is sometimes chosen for the stock because it is lighter and dissipates heat more efficiently.

The 3 types of engines that exist

Online engine

The simplest and most common type of engine is comprised of vertical cylinders together in a row. This is known as an online engine. The most common are the 4-cylinder, but there are 3, 5, 6 ...


It is one in which the cylinders are arranged one in front of the other, at an angle of up to 90 degrees, in order to improve performance. It is typical of high performance mechanics.

There are two-cylinder engines in V (custom bikes are very common). However, in the case of passenger cars, it is usual for engines with this arrangement to be 6, 8, 10 or 12 cylinders.

Boxer motor

Some engines have horizontally opposed cylinders and are known as a boxer. These are an extension of the V-engine, with an angle extended to 180ยบ. The advantages lie in the saving of height - by space and by center of gravity.

The behavior also varies in terms of performance, thrust, inertia ...