Abstract: An apparatus (10) for installation in an automobile (12) to generate steam with heat from the exhaust of an engine (14) is provided. The steam is generated at a sufficient pressure for entry into the combustion chambers of the engine to increase the power output of the engine. The apparatus includes a water storage unit (20) and a steam generator (26) for generating steam with the water from the unit through transfer of heat from combusted gases in the exhaust system (18). The steam travels through steam inlet manifolds (30, 32) for entry into the combustion chambers. The entry is controlled by a cylinder injection timing valve assembly (38) timed to the operation of the engine to enter the steam during the power stroke. A steam throttling control valve assembly (50) is provided to throttle the steam input to the cmbustion chambers.