Removable insert for internal combustion chambers

Claim 1

IN AN INTERNAL COMBUSTION ENGINE HAVING AN ENGINE BODY PROVIDED WITH A CYLINDER AND ASSOCIATED COMBUSTION CHAMBER PORTION HAVING A FLAT BOTTOM RECESS THEREIN, A PRIMARY INSERT RECEIVED IN SAID RECESS AND HAVING A FLAT REAR FACE FOR PRESSURE BEARING RELATIONSHIP TO THE FLAT BOTTOM OF SAID RECESS, SAID RECESS BEING SLIGHTLY LARGER THAN SAID PRIMARY INSERT TO PROVIDE PERIPHERAL CLEARANCE BETWEEN SAID PRIMARY INSERT AND SAID BODY, A PAIR OF VALVE SEAT INSERTS SNUGLY RECEIVED IN THE MAIN BODY PORTION OF SAID PRIMARY INSERT IN OFFSET RELATION TO EITHER SIDE OF A CENTRAL REGION OF SAID PRIMARY INSERT, FASTENING MEANS FIXEDLY SECURING THE CENTRAL REGION OF SAID PRIMARY INSERT TO SAID COMBUSTION CHAMBER PORTION LEAVING THE SURROUNDING AND MAIN BODY PORTION OF SAID PRIMARY INSERT, INCLUDING THE PERIPHERAL REGION THEREOF FREE TO EXPAND AND CONTRACT WITHIN THE STATED PERIPHERAL CLEARANCE TO MINIMIZE IN-PLANE STRESSES AND DISTORTIONS IN SAID PRIMARY INSERT, EACH VALVE SEAT INSERT BEING ENLARGED AT THAT END THEREOF ADJACENT TO THE FLAT BOTTOM OF SAID RECESS AND BEING ENGAGED AT ITS ENLARGED END AGAINST SAID ENGINE BODY BY SAID FASTENING MEANS.