Cylinder inlet passage for an internal combustion engine

Claim 1

IN AN INTERNAL COMBUSTION ENGINE, A CYLINDER, A CYLINDER HEAD CLOSING ONE END OF THE CYLINDER, MEANS DEFINING AN INLET PASSAGE THROUGH THE CYLINDER HEAD AND COMMUNICATING WITH THE CYLINDER, AND A POPPET INLET VALVE HAVING A CENTRAL AXIS AND RECIPROCABLY DISPOSED IN THE PASSAGE FOR CONTROLLING COMMUNICATION OF THE INLET PASSAGE WITH THE CYLINDER, SAID INLET PASSAGE MEANS BEING CHARACTERIZED BY; A THROAT PORTION OF GENERALLY CIRCULAR CROSS-SECTION OPENING INTO THE CYLINDER AND ADAPTED TO BE CLOSED BY THE INLET VALVE; AN ENTRANCE PORTION SPACED FROM THE THROAT PORTION AND OFFSET FROM THE VALVE AXIS; MEANS DEFINING A FLUID FLOW PATH EXTENDING FROM THE ENTRANCE PORTION AROUND ONE SIDE OF THE VALVE AXIS AND BLENDING INTO THE THROAT PORTION IN A DESCENDING SPIRAL CONFIGURATION, SAID FLUID FLOW PATH DEFINING MEANS INCLUDING A VALVE GUIDE BOSS SURROUNDING THE VALVE AXIS AND EXTENDING INTO THE FLOW PATH AND A SIDE WALL EXTENDING TANGENTIALLY FROM THE GUIDE BOSS TO THE ENTRANCE PORTION AND TERMINATING AT ITS LOWER EDGE IN A WEB CONNECTING THE GUIDE BOSS WITH THE THROAT PORTION, SAID WEB TERMINATING THE DESCENDING SPIRAL CONFIGURATION PORTION OF THE FLOW PATH; AND A FLOW DIRECTING VANE PROJECTING INTO THE FLOW PATH BETWEEN THE ENTRANCE PORTION AND THE THROAT PORTION, SAID VANE LYING IN A PLANE OFFSET FROM AND PARALLEL TO THE VALVE AXIS.