What does valve clearance refer to?

Valve clearance specifically refers to the gap between the valve stem and the rocker arm. This gap is crucial for proper engine function as it ensures that the valve can fully close against the cylinder head when not actuated, and allows the valve to open correctly when the engine operates. If the clearance is too small, it can lead to insufficient valve closing, potentially causing engine performance issues or even engine damage due to the valves remaining open. Conversely, if the clearance is too large, it can result in excessive wear on the valve train components and alter engine timing. Understanding valve clearance is essential for maintenance and tuning, as it directly affects engine efficiency and performance.