What does scavenging take place on a four stroke cycle diesel engine?

In a four-stroke cycle diesel engine, scavenging occurs during the intake stroke when fresh air is drawn into the combustion chamber. The exhaust stroke follows, where burnt gases are expelled, creating a pressure difference that helps pull in fresh air. While scavenging is more commonly associated with two-stroke engines, it is essential in four-stroke engines to ensure efficient combustion and minimize residual exhaust gases. Effective scavenging improves engine performance and emissions by ensuring a clean air-fuel mixture for combustion.