Abstract: A method of operating an internal combustion engine having one or a plurality of cylinders with piston means movable therein wherein a controlled quantity of compressed air is introduced into the combustion chamber when the piston is substantially in its bottom dead center position and about to begin a compression stroke or an exhaust stroke or only before the beginning of an exhaust stroke. The quantity of compressed air supplied is varied in dependence upon the load or output power of the engine. At lower engine speeds or lower output power a greater quantity of compressed air is introduced before each compression stroke. At higher engine speeds or higher output power a smaller quantity of compressed air is supplied prior to each compression stroke and each exhaust stroke. The scavenging and/or supercharging air is supplied at a pressure from about 7 to 43 psig, and at a temperature below 1470.degree. F., or lower.

Abstract: A method of operating an internal combustion engine having one or a plurality of cylinders with piston means movable therein wherein a controlled quantity of compressed air is introduced into the combustion chamber when the piston is substantially in its bottom dead center position and about to begin a compression stroke or an exhaust stroke or only before the beginning of an exhaust stroke. The quantity of compressed air supplied is varied in dependence upon the load or output power of the engine. At lower engine speeds or lower output power a greater quantity of compressed air is introduced before each compression stroke. At higher engine speeds or higher output power a smaller quantity of compressed air is supplied prior to each compression stroke and each exhaust stroke. The scavenging and/or supercharging air is supplied at a pressure from about 7 to 43 psig, and at a temperature below 1470.degree. F, or lower.