What is the objective of the exhaust stroke?

The objective of the exhaust stroke is to release the used air-fuel mixture from the combustion chamber. During this phase of the four-stroke engine cycle, the exhaust valve opens, allowing the spent gases – byproducts of the combustion process – to exit the cylinder. This is crucial because it clears the way for fresh air and fuel to enter the cylinder in the next intake stroke, ensuring optimal engine performance and efficiency.

By effectively expelling the burnt gases, the exhaust stroke helps maintain proper engine operation and prevents the buildup of pressure or unburnt fuel, which could lead to performance issues or engine damage. This process is vital for the continuous operation of the engine, enabling it to perform at its best in subsequent cycles.