Abstract: A spark ignited, piston type diesel fueled internal combustion engine is provided with a charge conditioning system that includes a fuel preheater for vaporizing liquid fuel to enable starting of the engine and a least one secondary heater for adding additional heat to the charge supplied to the engine. The fuel vaporizer receives liquid fuel from the starting fuel circuit of the engine and uses an electrically or chemically energized heater device, or a direct combustion heater. The secondary heater may be associated with the charge intake conduit of the engine or with the combustion chamber of the engine. The secondary heater device may be electrically or chemically activated, or may constitute a heat regenerator that retains heat from a previous combustion cycle of the engine.

Abstract: A piston for an internal combustion engine is provided with a reaction chamber for generating radical fuel species during a combustion cycle for use during the next succeeding combustion cycle. The reaction chamber is located adjacent a piston crown recess and is in communication with the main combustion chamber of the engine through discrete orifices that are intended to separately control the supply of fuel and air to the reaction chamber for fuel injected engines and to enhance reaction chamber function in fuel aspirating engines. The discrete fuel and air control orifices are particularly beneficial for use in high swirl, direct injected combustion chambers.