a view of the 4 cylinder engine after 90 degrees of travel from the piston positions of fig7 the 1 piston has just completed its first one half of travel on an exhaust stroke and has pushed the first one half volume of exhaust gas from cylinder 1 into reclaim cylinder 2 the gas or liquid expanding substance is injected into cylinder 2 at this point creating maximum 2 cylinder pressure the 3 piston is at tdc after an exhaust stroke and the 4 piston is midpoint traveling upwards in a compression stroke fig9 is a view of the 4 cylinder engine after 90 degrees of travel from the piston positions of fig8 at this time the 1 piston has just completed the second one half travel of an exhaust stroke and has pushed the second one half volume of exhaust gas from cylinder 1 into reclaim cylinder 3 a gas or liquid expanding substance is injected into cylinder 3 at this time creating maximum 3 cylinder pressure the 2 piston is bdc after a 50 travel power stroke and the 4 piston is tdc after a compression stroke fig1 is a view of the 4 cylinder engine after 90 degrees of travel from the piston positions of fig9 the 1 piston is now midpoint in an intake stroke the 2 piston is traveling upward in an exhaust stroke the 3 piston is bdc after a 50 travel power stroke and the 4 piston is midpoint in a downward power stoke fig1 is a view.