Abstract: A rotary-vane internal combustion engine comprising, in combination, a rotary compressor for forming and igniting a combustible fluid mixture, a rotary power unit, and an expansion chamber that is connected both to the compressor for receiving the ignited mixture, and to the power unit, where the power developed by the expanding ignited combustible mixture in the expansion chamber drives a vane acting on a driven member.In each of the compressor and power units respective rotors are mounted for rotation. A plurality of vanes rotatably supported by a shaft within each rotor rotates with the rotor and slide in slots in guides mounted with the rotor. The rotor within the compressor is mounted eccentrically so that the fluid is compressed before it is ignited and leaves the compressor.The combustible fluid, after ignition, enters the expansion chamber where it drives one or more vanes coupled to the rotor mounted eccentrically within the rotary power unit.