support bearings and with a front outlet in the form of an elbow shaped duct 97 which supports ventilator 95 the latter forces out the exhaust gases the intermediate housing 99 consists of a bulkhead with flat parallel faces with friction paths 90a on both sides this bulkhead contains in addition to the lubrication cooling and shaft support systems an air transfer tunnel whose intake 101 allows passage of air from the intake chamber of the auxiliary rotor piston 70a in the direction of the compression chamber of the rotor piston 70 under the intake 101 the tunnel outlet 100 is shown as a diabatic tunnel through which the first expansion gases flow toward the post expansion chamber under the rotor piston 70a section a a fig2 shows section a a in fig2 a schematically to provide the placement of the moving elements already explained as well as intake mouth 98 and the lateral port 107 through which the fresh air will penetrate to cool the rotor 70a and will then pass out through the port 107 39 reference numeral 104 identifies the purge valve regulated to work at intervals by means of electrical impulses it is the function of the valve to control the quantity of air or gas to be recirculated toward the combustion chamber and the post combustion chamber fig2 shows section b b of fig2 a where a layout similar to the foregoing is repeated in addition it indicates the injection method 102 and ignition 103 distributed on the combustion chamber in this same.