Abstract: An engine including at least one set of three cylinders. Two of the cylinders function as internal combustion cylinders and the remaining cylinder functions as an air compressor. The air is injected into the exhaust manifold of the combustion cylinders. The combustion products are fed to a steam generator, the steam being utilized to produce work in a steam engine or turbine. The supply water for the steam generator is in heat exchange relationship with the engine cooling liquid. The compressor intake air is in heat exchange relationship with the engine lubricating liquid.