Sealing shroud port timing valve for two-stroke cycle engine.

摘要

An exhaust port timing valve (100) for a two-stroke cycle engine has a sealing shroud (99) preferably made as a flexible sheet that is urged by gas pressure into sealing contact with a slot (98) and/or sealing edges of an associated exhaust port or shroud (92) to allow low-friction valve adjustment whilst limiting gas leakage past the valve (100), which adjustment is unaffected by close tolerances and temperature changes in the valve (100). Springs (118) and/or seals (116) can alternatively be used with flexible or non-flexible shrouds (99) to improve sealing.