Abstract: The mixed gas engine in accordance with the invention is used to obtain a power that is transmitted to a shaft to turn it, and it is made up of an oilbath body subassembly A containing a crankshaft-connecting rods-piston subassembly B, and over which is a cylinder unit subassembly C, a recuperator distributor body subassembly D containing a rocker shaft subassembly E, a camshaft subassembly F1 and another recuperator distributor subassembly G that also contains a rocker shaft subassembly H and a camshaft subassembly I, all connected to a pressurized circuit consisting of pressure pipes 164, a valve 165, a manometer 166, a bottle 167, and a compressor 168, known and not marked.