Which component is primarily responsible for the airflow into the cylinder during the intake stroke?

The intake valve plays a crucial role in allowing air (or air-fuel mixture) to enter the combustion chamber during the intake stroke of a four-stroke engine. When the piston moves down during this stroke, it creates a vacuum inside the cylinder. This drop in pressure causes the intake valve to open, enabling air to flow into the cylinder from the intake manifold.

The design and timing of the opening and closing of the intake valve are critical for optimal engine performance since they directly affect how much air enters the cylinder, influencing combustion efficiency and power generation. An effectively functioning intake valve ensures that the engine receives the right amount of air for the combustion process, which is essential for producing the desired output and maintaining engine health.