Abstract: A spark-ignition, air-compressing, internal combustion engine having a combustion chamber in the shape of a body of revolution with a constricted opening in the piston crown. The injection nozzle is located in the cylinder head near the edge of the combustion chamber and the spark plug, opposite the injection nozzle, extends into the combustion chamber at the top dead center position of the piston. Mixture formation is predominantly by deposition of the fuel on the combustion chamber wall. In such an internal combustion engine, it is desired in applying the concept to a supercharged engine to satisfy the enhanced requirements with respect to mixture formation reliably in all ranges of operation, whereby a further improvement of ignition stability is also to be provided. This is essentially achieved by the special shape and proportioning of the combustion chamber, and in particular by the use of two arcs to form the side wall thereof, and a third arc, which joins the side wall, to form the bottom.

Abstract: A spark-ignition, air-compressing internal combustion engine has a combustion chamber in a piston movable toward a cylinder head of the engine. Fuel is injected onto the wall of the combustion chamber and air rotated in the chamber to remove the fuel from the combustion chamber wall gradually as a vapor. The cross-section of the combustion chamber wall is defined by two curved lines of specific radial relation generally indicated by the curved line extending from the opening into the combustion chamber having the smaller radius of curvature.