How Does a Car Engine Work?

George Brown, 6 years ago

5 min read

  • Advice
  • howdoesitwork
A car's engine.

Getting into your car and putting your key in the ignition is a simple motion that you do everyday without thought. But we rarely think about the chain of events that occur underneath the hood of car as soon as your car key sends the first signal.

Just like your body needs food, your car needs fuel in the form of petrol or diesel. Similarly to the way your body converts the food you eat into energy, your car’s engine converts the fuel into motion that helps move the car. A car takes 20,000 cubic feet of air to burn 20 gallons of gas, the equivalent of six football pitches. The method of converting gas into motion is known as internal combustion, which uses little, controlled explosions that create the power needed to start a car.

When you turn your key in the ignition, a spark plug sets the car’s fuel on fire, moving it to the piston. The piston then creates a tiny explosion in an enclosed space. Because it is in such an enclosed space, a large amount of energy is released in the form of expanding gas.

Your car’s engine will make hundreds of explosions a minute, and the energy from these explosions are used to propel the car. Once the energy from the first explosion has nearly run out, another explosion happens, forcing the pistons to move again. This is a continuous cycle and gives the car constant power that is needed to run. The more pistons a car has, the more power it generates, therefore making it faster.

Your car engine utilises a four-stroke combustion cycle. This is made up of four steps; intake, compression, combustion and exhaust. These strokes are continuously repeated and generate the power needed to start your car and keep it going.

The Intake Cycle

This is the first step of the combustion cycle. The intake valve opens and the piston moves down, and brings gas and air into the engine.

The Compression Cycle

The compression cycle is the second step of the cycle. The piston moves up, pushing the air and gas into a smaller space giving a more powerful explosion.

The Combustion Cycle

The penultimate part of the cycle uses the spark plug to create a spark that ignites, causing the gas to explode. Due to the power of the explosion, it forces the piston to back down.

The Exhaust Cycle

In the final part of the cycle, the exhaust valve opens and releases waste gas that is a result of the explosion. This gas moved and cleaned when it goes through the catalytic converter. The gas then goes through the muffler and then exits the car via the tailpipe.

If you think your car’s engine needs a bit of TLC, or you need to find a local garage that will help fix your car why not try WhoCanFixMyCar? We’ll find the best garage to help suit your needs. If you have any questions the do not hesitate to get in touch.