How does fuel burn in a car engine?

The four-stroke cycle

The four-stroke cycle is the most common type of engine cycle used in car engines. It is a four-step process that involves:

1. Intake stroke: The intake valve opens and the piston moves down, drawing air and fuel into the cylinder.
2. Compression stroke: The intake valve closes and the piston moves up, compressing the air and fuel mixture.
3. Power stroke: The spark plug ignites the air and fuel mixture, causing it to burn and expand. This expansion forces the piston down, generating power.
4. Exhaust stroke: The exhaust valve opens and the piston moves up, pushing the exhaust gases out of the cylinder.

The fuel injection system

The fuel injection system is responsible for delivering fuel to the engine’s cylinders. There are two main types of fuel injection systems: port fuel injection (PFI) and direct fuel injection (GDI).

In a PFI system, the fuel injectors are located in the intake manifold. They spray fuel into the airstream as it enters the cylinder. In a GDI system, the fuel injectors are located directly in the cylinder. They spray fuel directly onto the back of the intake valve.

The ignition system

The ignition system is responsible for igniting the air and fuel mixture in the cylinders. It consists of a battery, a coil, a distributor, and spark plugs.

The battery provides the power for the ignition system. The coil steps up the voltage from the battery to a high voltage that is needed to create a spark. The distributor distributes the high voltage to the spark plugs.

The spark plugs are located in the cylinder head. They create a spark that ignites the air and fuel mixture.

The exhaust system

The exhaust system is responsible for removing the exhaust gases from the engine. It consists of an exhaust manifold, a catalytic converter, and a muffler.

The exhaust manifold is a series of pipes that collect the exhaust gases from the cylinders. The catalytic converter converts the harmful pollutants in the exhaust gases into less harmful substances. The muffler reduces the noise of the exhaust gases.

Conclusion

The combustion of fuel in a car engine is a complex process that involves many different components. By understanding how these components work, you can better understand how your car operates.