Abstract: A Dual Piston Cycle Engine utilizes a unique dual piston apparatus that includes: a first cylinder housing a first piston therein; a second cylinder thermally isolated from the first cylinder and housing a second piston therein; an intake valve coupled to the first cylinder for allowing a fuel mixture to enter into the first cylinder; an exhaust valve coupled to the second cylinder for allowing an exhaust gas to exit the second cylinder; and an interstage valve that couples an internal chamber of the first cylinder to an internal chamber of the second cylinder and configured to minimize dead space between the first and second cylinders, wherein the first piston performs only intake and compression strokes and the second piston performs only combustion and exhaust strokes and the first and second cylinders are thermally isolated from one another.

Abstract: A steam enhanced dual piston cycle engine utilizes a unique dual piston apparatus that includes: a first cylinder housing a first piston therein, wherein the first piston performs only intake and compression strokes; a second cylinder housing an inner power piston that forms an inner internal chamber of the second cylinder, and either a ring-shaped outer power piston surrounding the inner power piston, wherein the outer power piston forms an outer internal chamber of the second cylinder and is configured to convert engine heat into additional work, and/or an outer boiler which is configured to produce steam to be converted into additional work.