hydraulic valve lifter

A hydraulic valve lifter is a component in internal combustion engines that helps open and close valves, which control the intake of fuel and air and the exhaust of gases. These lifters are part of the valve train, which is synchronized with the engine's crankshaft to ensure precise timing of valve operation during the four-stroke cycle.123

Hydraulic lifters automatically adjust for any clearance in the valve train, eliminating the need for manual adjustments. They use engine oil to maintain a constant contact between the valve train components, ensuring that valves close completely and quietly. This feature contributes to smoother engine operation and reduces wear.23