Abstract: A piston for an internal combustion engine comprises a piston body of aluminium or aluminium alloy and an insert of a ferrous material having a combustion bowl formed therein. The insert is surrounded by the piston body and the outer surface of the insert and the adjacent surface of the piston body are spaced apart at the crown ends thereof to form an annular gap therebetween which opens onto the crown. This insulates the piston body from the insert.

Abstract: An aluminum cylinder head for an internal combustion engine has a layer of material of dispersion-hardened sintered aluminum disposed in its bottom wall which forms a combustion chamber wall, the layer comprising an insert or inserts at the sealing surface which delimits the combustion chamber and at the bridge between the intake and exhaust ports in the head for increasing the resistance of the head member to thermal shock at the bridge and for retaining for the sealing surface a high residual hardness at elevated temperatures.

Abstract: A diesel engine is provided with extenders or spacers attached to those portions of the cylinder block, cylinder head and piston that define the combustion chamber, the extenders being of substantial axial extent and of low thermal conductivity to insulate the components to which they are attached from the combustion chamber while redefining the combustion chamber surfaces.

Abstract: An oil cooling system for an internal combustion engine (2) includes a cylinder liner (22) shaped to form an annular oil flow passage (36) by an inner flow control surface (52) and outer flow control surface (56) through which engine lubrication oil flows in a very thin film under laminar flow conditions to produce a very large convective heat transfer coefficient of 300-400 BTU's per hour-feet squared-degree Fehrenheit. To insure laminar flow conditions, the radial thickness of the annular flow passage 36 is held to less than 0.016 inches and is preferably in the range of 0.008 to 0.010 inches. The disclosed liner (22) is very accurately positioned within a cylinder bore (8) of the engine block (4) by liner stop means (68) for retaining the liner in a fixed axial position within the cylinder bore (8) and by inner and outer radial locating means (106 and 101) positioned, respectively, inwardly and outwardly of the inner flow control surface (52).

Abstract: A ceramic cap is attached to a metal piston by means of intermeshing radial flanges. A spring forces the flanges into contact with one another along an annular surface area. Spaces between the flanges allow for movement between the metal and ceramic parts to accommodate differential thermal expansion, while at the same time permitting secure contact between metal and ceramic.

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.

Abstract: Heat conducting shield member for cylinder heads of internal combustion engines having at least two gas change ports with valve seat rings at their combustion chamber end, with the valve bridge portion between the valve seat rings shielded by the shield member against the combustion chamber. The shield member is formed as a heat conducting shield which in the area of the valve bridge portion between the bridge and the cylinder head wall forms a hollow space and is in full contact with the cylinder head in the area of cylinder head wall members which can be readily cooled.

Abstract: A heat-insulating layer secured to a cast metal member of an internal combustion engine so as to be exposed to combustion gas in the engine. A porous or intersticed metal body, preferably having a soft structure, is used as a fundamental material of this layer. A surface portion of the porous metal body is impregnated with a ceramic material, and then the metal body is cast-inserted into the metal member such that the molten metal infiltrates into another surface portion of the porous metal body and that the ceramic-impregnated portion is exposed to combustion gas in the engine. This heat-insulating layer is excellent in toughness, durability and bonding strength and can be embodied in a combustion chamber wall, exhaust port wall or a top portion of a piston.

Abstract: Internal combustion engine pistons are provided with aluminum bodies with highly insulative ceramic inserts cast in place in the upper combustion chamber defining wall. In each of the disclosed embodiments, the ceramic insert has tapered edges to dovetail the insert in place. A fibrous ceramic cushioning layer applied around the insert edge before casting distributes cooling stresses and allows limited relative expansion and contraction of the aluminum body and ceramic insert without overstressing either of the members. Other features are also included.