Abstract: A rotary engine comprising a rotor having mounted thereon a plurality of radially reciprocating pistons and a cam that controls the opening and closing of the compression chamber valves which are located, together with combustion chambers, beyond the radially outward ends of the pistons. By so remotely locating the combustion chambers and spark plugs therefor, the heat of combustion is separated from the pistons and cylinders, whereby they can operate in a relatively cool atmosphere, use very little oil and reduce wear of parts to an absolute minimum so as to lengthen the life of the pistons many fold. The rotary engine produces greater torque, uses less fuel per horsepower developed and emits less exhaust pollutants. Also there is less wearing of parts, therefore less maintenance and much longer life than engines of the prior art.