AIR VALVE FOR IMPROVING THE PERFORMANCE OF AN INTERNAL COMBUSTION ENGINE
An air valve for an internal combustion engine, said air valve comprising a valve body, a passage in said body, valve moans adapted to normally close said passage to prevent egress therethrough of spent combustion products from said engine and to open on creation of a pressure drop within the engine to permit air to flow through the passage into the engine. The valve means comprises a flexible valve element engageable with a valve seat associated with said passage, and means for tensioning said flexible valve element to assist effective operation of the valve element.