NOVELTY - The engine (10) has a helical flow guide (57) formed in a cooling jacket (52) for causing a coolant (36) to flow in a circuitous pathway. A pump transfers the coolant between a portion of the jacket adjacent to a cylinder (18). A heat exchange coupling arranged between the coolant and a steam condensate transfers heat to the condensate from the coolant. A duct (77) is connected to transfer the condensate to a superheater (104) that is fired by multiple exhaust gases from the chamber for providing steam produced from the condensate to a steam expansion chamber (70).    USE - Combined cycle engine e.g. dual cycle internal combustion steam engine or dual cycle internal combustion piston engine such as a4 cylinder automobile engine and spark ignition petrol engine, for use in a vehicle e.g. car and truck. Can also be used for an a4 stroke spark ignition engine, a diesel engine, a two-stroke cycle engine and Atkinson cycle engine.    ADVANTAGE - The engine provides differential cylinder temperature distribution that occurs as a result of combustion and gas expansion. The cooling jacket has a design tailored to extract heat at highest possible temperature from each heat transfer zone by allowing the coolant to follow through a circuitous pathway of a selected configuration to achieve more efficient and improved heat transfer from the combustion chamber to the coolant in a reliable manner, thus allowing greater heat transfer to a vaporizable working fluid used in a steam expander.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a high efficiency method for operating a dual cycle engine.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of a combined cycle engine including a cylinder and showing a flow of a coolant liquid and a heat exchange medium that serves as a working fluid in a steam expander.    Combined cycle engine (10)    Cylinder (18)    Coolant (36)    Cooling jacket (52)    Helical flow guide (57)    Steam expansion chamber (70)    Duct (77)    Superheater (104)