Abstract: Thin thermal barrier coating of a specified thickness of 0.002 to 0.009 inch to insulate the combustion chamber of an internal combustion engine to achieve optimum reduction of transient head flow. The coating is of an optimum thickness to reduce in-cylinder heat loss in the combustion chamber during combustion, thus increasing engine efficiency, specific power output, and reducing emissions. However, the temperature increase is not so great as to adversely affect engine lubricant life or volumetric efficiency. The invention is particularly suitable for gasoline engines as it does not cause preignition or knocking that is generally caused by insulating coatings of greater thickness. In addition, the invention is particulalry suitable for aluminum combustion chamber components. The thinner coating also results in improved reliability and durability by reducing chipping and cracking failure tendencies associated with ceramic coatings.

Abstract: A replaceable monolithic, hollow, generally cylindrical cylinder liner formed of hot pressed silicon nitride adapted for operating at the high engine temperatures caused by fuel combustion and friction within the liner without need for liquid cooling thereof. The liner includes a surface adjacent its outer end for forming a radial press fit with the inside surface of the cylinder cavity and a stop-engaging surface formed on the cylindrical liner surface spaced axially inwardly of the press fit surface or along the innermost face of the liner for engaging an engine block liner stop within the cylinder cavity.

Abstract: A piston-cylinder assembly of an internal combustion engine is provided which includes a cylinder liner mounted within a bore formed in an engine block, and a cylindrical spacer extending axially and endwise from the liner and coacting therewith to form a cylinder in which a piston is mounted for reciprocatory movement. An end piece overlies an end of the spacer and is supported by the latter. The end piece substantially closes off one end of the cylinder and the piston is in close proximity thereto when at one stroke limit. When the piston is at the one stroke limit, it coacts with the end piece and the spacer to define a combustion chamber. The end piece is secured in assembled relation with the spacer by a first means. A second means is provided for effecting substantial thermal insulating of the block, liner and first means from the heat of combustion which is generated in the combustion chamber during operation of the engine.

Abstract: A combustion chamber for an internal combustion engine is provided having a cylindrical member, an end piece overlying one end of the member, and a piston mounted for reciprocatory movement within the member and when at a predetermined relative position, coacting with the end piece and member to form a combustion cavity. A compliant gas seal is positioned between the end piece and member and is in surface contact therewith. The seal encompasses the combustion cavity and has a portion thereof continuously exposed to the cavity.