A universal heat engine is disclosed for converting energy from an input heat source to an output. The universal heat engine comprises a heat engine section and an output section. The heat engine section includes a heat engine bore receiving a heat engine piston. A heat engine valve assembly communicates with the heat engine bore for effecting reciprocal motion of the heat engine piston. The output section includes an output bore receiving an output piston. A piston rod interconnects the heat engine piston to the output piston. A control controls the heat engine valve assemblies to operate the heat engine section in accordance with a desired output from the output section. The heat source may comprise the burning of a petroleum product, a solar heat source, geothermal heat source or a byproduct heat source. The output may comprise a static or mobile air conditioning system or an electrical generator.
