An internal combustion engine having a fuel/air induction system having a crankshaft-driven compression piston that is reciprocated within a fuel/air compression cylinder in a cooperative operation which fills a combustion cylinder with a quantity of fuel/air mixture under pressure during each engine cycle. A combustion piston within the combustion cylinder is reciprocated by the engine crankshaft to further compress the fuel/air mixture charge and harness the power of the ignited mixture.