Abstract:
An inlet manifold active reed valve for an internal combustion spark ignition engine comprises a solenoid activated reed just upstream of the inlet poppet valve of a four stroke engine. For a two stroke engine the active reed valve is located at the entrance to the crankcase and activated by one or more miniature solenoids attached to the valve body. As an alternative, the new valve is a rotary disc valve reciprocated by an external solenoid or a rotary activator. The valve opens fully for full unrestricted flow (unthrottled) during a portion of the time the inlet valve or part is open (in terms of crankshaft angle). The portion of crankshaft angle the new valve is fully open is determined by the engine load. Under full load the new valve may be held constantly open to provide unrestricted flow to the engine inlet valve or crankcase. In the above embodiments an electronic control unit energizes the solenoid or activator in response to engine operating conditions and pollution control regulations.