The Axial Combustion Engine (ACE) is a novel heat engine that uses a rotating rotor inside a stationary casing to generate power. The rotor has engine wafers stacked in parallel that each contain 12 cavities which perform different functions as they rotate, acting as combustion chambers. Compressed air and fuel are injected into the cavities at certain positions, ignited by spark plugs, and the expanding gases power the rotation of the rotor. As rotor speed increases, fuel injection and ignition are timed to different cavity positions for more complete combustion. The prototype ACE engine is designed to burn various fuels and could be used as a generator or vehicle range extender.