What role do exhaust valves play during the combustion cycle?

Exhaust valves play a crucial role in the combustion cycle by opening at the right moment to allow exhaust gases to escape from the combustion chamber after the combustion process has taken place. This occurs during the exhaust stroke of the four-stroke cycle. When the piston moves upward in the cylinder, the exhaust valves open, creating a pathway for the burnt gases to exit the engine. This process is essential for maintaining efficient engine operation, as it ensures that the next cycle can draw in a fresh air-fuel mixture without the interference of residual exhaust gases. Proper functioning of the exhaust valves is vital for engine performance, emissions control, and overall efficiency.