Pulse Air Injection System: Operation

Each of the check valves in the plenum chambers is connected to an exhaust port. Firing of the engine creates a pulsating flow of exhaust gases. When positive exhaust pressure is felt, check valve will be forced closed.

No exhaust gas will flow past valve into fresh air supply line. With negative exhaust pressure (vacuum), check valve will open. Fresh air will be drawn and mixed with exhaust gases. During high engine RPM, such as under heavy acceleration, check valve will remain closed.