Abstract: An oil pressure chamber is coupled to the input of a turbine for driving the turbine with hydraulic fluid under pressure. A lower cylinder has a piston movably mounted therein for movement in axial directions. The output end of the lower cylinder is coupled to the oil pressure chamber. An upper cylinder has a piston movably mounted therein for movement in axial directions and coupled to the piston of the lower cylinder for movement therewith. A hydraulic fluid supply is coupled to the output end of the lower cylinder for supplying hydraulic fluid to the lower cylinder. A fuel and air mixture supply is coupled to the output end of the upper cylinder for supplying a fuel and air mixture to the upper cylinder. A coupling device couples the output end of the upper cylinder to the input end of the lower cylinder whereby movement of the piston from the input end to output end in the upper cylinder compresses the fuel and air mixture and supplies it to the input end of the lower cylinder.