Which component determines the timing of valve openings and closings?

The camshaft is the component responsible for determining the timing of valve openings and closings in an engine. It operates in conjunction with the crankshaft to ensure that the engine's valves open and close at the correct intervals during the four-stroke cycle (intake, compression, power, and exhaust).

As the camshaft rotates, its lobes push against the valves, forcing them to open. The design of the camshaft, including the shape and positioning of the lobes, directly influences the timing and duration that each valve remains open. Proper timing is crucial for engine performance, efficiency, and emissions control.

Other components mentioned serve different functions; for example, the crankshaft converts linear motion into rotational motion, the flywheel smooths out power delivery by maintaining momentum, and the governor arm helps regulate engine speed but does not directly control valve timing.