Air Injection System

The air injection system used on the Mazda rotary engine differs from the type used on a conventional piston engine in two respects:

1. Air is not only supplied to burn the gases in the exhaust ports, but it is also used to cool the thermal reactor.
2. A three-way air control valve is used in place of the conventional anti-backfire and diverter valves. It contains an air cut-out valve, a relief valve, and a safety valve.

   Air is supplied to the system by a normal vane type air pump. The air flows from the pump to the air control valve, where it is routed to the air injection nozzles to cool the thermal reactor or, in the case of a system malfunction, to the air cleaner. A check valve, located beneath the air control valve seat, prevents the back-flow of hot exhaust gases into the air injection system in case of air pressure loss.

   Air injection nozzles are used to feed air into the exhaust ports, just as in a conventional piston engine.