During which part of the cycle does cylinder scavenging occur, according to Technician B?

Cylinder scavenging plays a critical role in the efficiency of an engine's operation, particularly in two-stroke engine designs. During the valve overlap period, both the intake and exhaust valves are open at the same time. This moment allows for the leftover exhaust gases to be pushed out simultaneously as fresh air-fuel mixture is drawn in. As a result, effective scavenging takes place, improving the engine’s ability to clear out exhaust and draw in new intake charge, thus enhancing performance.

During valve overlap, the design facilitates a flow that helps to fill the cylinder more completely with fresh charge and contributes to thorough cleansing of exhaust gases remaining from the previous cycle. This is essential for maintaining good operational efficiency and minimizing emissions. Therefore, understanding this timing and the mechanism of scavenging is crucial for diesel technicians, as it directly impacts engine performance.