Air cooled self-supercharging four stroke internal combustion engine

摘要

An air-cooled self-supercharging four stroke internal combustion engine having four pistons which move in unison. There are two downward piston strokes in each four stroke cycle. The downward strokes of the pistons are used to compress the air in the crank case and supercharge the engine by forcing more air and fuel into the two combustion chambers. Each combustion chamber serves two piston cylinders. The compressed air and fuel mixture is forced into only one combustion chamber during each downward stroke of the pistons. The two combustion chambers are charged with air and fuel on alternating downward piston strokes. The engine is air-cooled by the flow of the combustion intake air which passes through the crank case. At the same time, heat transferred from the engine pre- heats the intake air to improve combustion efficiency.