Abstract: A rotary internal combustion engine of the Wankel type having a housing with a two lobed epitrochoidal inner peripheral surface, a shaft journalled in end housings and a rotor eccentrically mounted on the shaft and geared to rotate at one third the speed of said shaft whereby working chambers are formed between the flanks of the rotor and the housings which vary in volume as the rotor rotates. The rotor is cooled by a fully closed circuit system wherein pressurised gasses are circulated by a centrifugal fan which is directly mounted on the main eccentric shaft, and circulates the gases through a heat exchanger which is integrated into the cool sector of the rotor housing, all components being enclosed within the pressurised system and only one drive shaft using a single high pressure shaft seal assembly emerges from this system.