ventilslift

Ventilslift is a term used in mechanical engineering, primarily in Swedish contexts, to describe valve lift—the linear displacement of a valve from its fully closed position to its fully open position along the valve stem. It is determined by the actuation mechanism, such as a cam profile in engines or an electric, hydraulic, or pneumatic actuator in industrial valves, and is a key parameter in describing valve motion.

In internal combustion engines, valve lift is governed by the camshaft, followers or rockers, and sometimes pushrods. The lift, together with valve timing and duration, dictates how much air and exhaust gas can flow through the intake and exhaust ports. Some engines use variable-lift or adjustable-lift systems to alter lift during operation, improving efficiency or power across different RPM ranges.

In process control and industrial valve systems, lift refers to the travel of a valve stem as the actuator moves the valve toward the open or closed position. The maximum lift depends on the valve design (gate, globe, ball, etc.) and mechanical stops, and it affects flow capacity and pressure drop across the valve.

Typical lift values vary widely. Small engines may have lifts of roughly 5 to 12 mm, while larger automotive and motorcycle valves commonly range higher. Industrial valves can exhibit lifts from several millimeters to several centimeters, depending on the application and required flow.

See also valve lift, camshaft, valve train, actuator.