160 degrees 175 degrees past top dead center for example valves v are shown for controlling the flow of the injection of the water and may be controlled by an overall engine control in a manner that would be apparent to a worker of skill in this art while cam shafts are shown for controlling the operation of the several cylinder valves other means of valve timing such as electronic valve controls may be utilized fuel and air fed combustion cylinders 32 and 34 may fire nominally at 0 degrees and 360 degrees of rotation respectively the cylinders 32 34 alternate intake and power strokes while the expansion cylinder 33 executes an exhaust stroke during the exhaust stroke gases exit the expansion cylinder through a valve not shown each cylinder 32 34 contributes torque to a crankshaft 52 through the power stroke the combustion cylinders 32 34 alternate compression and exhaust strokes while the second cylinder 33 is executing a power stroke in the power stroke the piston 50 in the expansion cylinder is driven by expansion of the steam and exhaust gas the expansion cylinder 33 expands the exhausted gas of the cylinder 32 beginning nominally at 180 degrees of rotation and then after completing an exhaust stroke the cylinder 33 alternately further expands the emission from the cylinder 34 beginning nominally at 540 degrees of rotation in a two stroke fashion in one example.