Abstract: A rotary vane internal combustion engine wherein the section of the rotor housing where ignition takes place is formed in the shape of a circular arc matching the curvature of the rotor, with the balance of the housing periphery being composed of a series of tangent arcs to define an elliptical shape that is continuously concave and has no drastic changes in curvature. The rotor and housing are "stretched" along their axial dimensions so that each combustion chamber has an axial measurement substantially greater than its circumferential measurement, and each segment of the rotor surface between adjacent vanes has formed therein a plurality of combustion chamber pockets spaced from one another along the axial dimension of the rotor and each provided with a spark plug.