A General Motors valve lifter, also known as a tappet, is a crucial engine component that plays an integral role in controlling valve timing and operation. Positioned between the camshaft and the engine’s valves, the valve lifter receives the camshaft’s rotational motion and transmits it to the valve pushrods, rocker arms, or directly to the valve itself, depending on the engine design. This ensures that the engine’s intake and exhaust valves open and close at the correct times during the engine’s cycle. Valve lifters are essential for maintaining optimal engine performance, efficiency, and longevity, as they help control the airflow into and out of the combustion chamber. GM valve lifters are typically engineered for durability, precision, and performance, ensuring smooth operation in various driving conditions.