Abstract: An internal combustion engine (10) comprises an engine block (12) having at least one combustion cylinder (18), an air intake port (56) and an exhaust port (58) each in communication with the combustion cylinder (18), a piston (16) reciprocatingly disposed within each combustion cylinder (18), and an exhaust stack (26) in communication with each exhaust port (58). A heat transfer system (28) has a circuit tube (32) with a first portion (34) in heat transfer relationship with the exhaust stack (26), a second portion (42) defining a heat conduction area, a flow valve (38) in the circuit tube (32), and a heat transfer agent within the circuit tube (32). A cooling system (30) has a circuit conduit (44) with a first section (52) defining a heat receiving area in thermal contact with the heat conduction area (42) of the heat transfer system (28).