The invention provides a friction-welded structure assembly, comprising a first workpiece (10B), a second workpiece (10C) and a friction welding connecting part (10A). The lower side of the friction welding connecting part (10A) has a first friction welding junction interface (10H) which is in contact with a surface of the first workpiece (10B) and a second friction welding junction interface (11H) which is in contact with a surface of the second workpiece (10C). The friction welding connecting part (10A) is tightly pressed on both the first workpiece (10B) and the second workpiece (10C) which are positioned to be relatively corresponding and fixed to each other, while being moved under a pressure, so as to heat said first friction welding junction interface (10H) and said second friction welding junction interface (11H), then said friction welding connecting part (10A) is stopped under the pressure, and said first friction welding junction interface (10H) and said second friction welding junction interface (11H) become cool, thereby said first workpiece (10B) and said second workpiece (10C) are welded together to form the friction-welded structure assembly via said friction welding connecting part (10A). Also, The invention relates to a water-cooled internal combustion engine cylinder head using the friction-welded structure assembly described above.

The invention provides a cylinder head gasket installed by being sandwiched between a cylinder block and a cylinder head of an internal combustion engine. The cylinder head gasket has bore holes each having a circular plane at positions which are lapped over a combustion chamber in said cylinder block, and surface pressure generation portions constructed by three-dimensional shapes surrounding said bore holes at positions which are lapped over partition walls between the combustion chamber in said cylinder block and a water jacket portion. The surface pressure generation portions are arranged at fixed positions in a thickness direction of said partition wall and are arranged closer to the combustion chamber side or the water jacket portion side than the fixed positions in the thickness direction of said partition wall partly on a circumference around the bore holes. Therefore, bore deformation can be reduced.

A method includes spraying a coating on to an engine bore surface, honing the coated surface to create a honed surface region, and cleaning the honed surface region to remove material from the surface pores. The honed surface region includes a plurality of surface pores and upper, middle, and lower regions. Cleaning the honed surface region produces upper, middle, and lower region surface porosities, with the middle region porosity being greater than at least one of the upper and lower porosities.

A method includes spraying a coating on to an engine bore surface, honing the coated surface to create a honed surface region, and cleaning the honed surface region to remove material from the surface pores. The honed surface region includes a plurality of surface pores and upper, middle, and lower regions. Cleaning the honed surface region produces upper, middle, and lower region surface porosities, with the middle region porosity being greater than at least one of the upper and lower porosities.

A piston for an internal combustion engine has a lower piston part and an upper piston part connected with the lower piston part by welding to form jointly a circumferential cooling channel having inner and outer circumferential walls. The welding process forms weld seams that curl outwards on the inner and outer circumferential walls. An insert is disposed in the circumferential cooling channel. The insert is placed in the cooling channel prior to welding of the upper and lower piston parts, and is clamped in place by at least one of the weld seams that projects into the cooling channel. This way, no additional fabrication or steps need to be taken to hold the insert securely in place in the cooling channel.

A piston assembly and method of construction thereof for an internal combustion engine are provided. The assembly includes a piston head having an upper combustion wall with an undercrown surface and a ring belt region. The piston head has a floor with an upper surface and a bottom surface. The floor is spaced beneath the upper combustion wall in radial alignment with the ring belt region. A substantially enclosed, annular cooling gallery is bounded by the undercrown surface and the floor. A pair of pin bores depends directly from the floor of the cooling gallery. The assembly further includes a pin having ends configured for oscillating receipt in the pin bores. A pin bearing surface extends within the pin bores and between the pin bores in the lower surface of the floor. The assembly includes a connecting rod with an end fixed to the pin for conjoint oscillation therewith.

A barrier ring for a cylinder assembly for an opposed-piston engine fits into a groove fashioned into a portion of the cylinder liner that is adjacent to the top dead center location of the end surfaces of the pistons, in a volume of the cylinder liner that defines the combustion chamber. The barrier ring and groove are part of a barrier assembly that prevents heat generated during combustion from reaching the outer wall of the cylinder assembly, reducing the need for conventional cooling systems and increasing the amount of heat retained in the combustion chamber. The barrier assembly allows for increased engine efficiency because of the combustion heat retained in the combustion chamber, as well as a reduction in the overall size of the engine because of the reduction in engine cooling needed.

A method for remanufacturing an engine block is provided. The engine block includes a damaged area on an inner surface of a cylinder. The method includes removing a first liner from the cylinder. The first liner includes a first inner diameter defined by a first inner surface and a first outer diameter defined by a first outer surface. The method includes removing material from the damaged area on the inner surface of the cylinder. The method also includes providing a machined surface on the inner surface of the cylinder. The machined surface defining a machined diameter. The method further includes inserting a second liner into the cylinder. The second liner includes a second inner diameter defined by a second inner surface and a second outer diameter defined by a second outer surface. The second outer diameter is equal to the machined diameter.

A cylinder head assembly includes a cylinder head having an igniter mount that forms a portion of a fireside surface of the cylinder head. The assembly further includes a sleeve abutting the igniter mount within an igniter bore in the cylinder head, such that the sleeve and the cylinder head together form an igniter cooling passage circumferential of the igniter mount, and extending axially between the sleeve and the cylinder head. The configuration of the igniter mount and sleeve improves heat dissipation and reduces likelihood of pre-ignition in an internal combustion engine.

Disclosed are a cylinder liner for insert casting and a method for manufacturing the same. In particular, the cylinder liner for insert casting has cooling and warming performances suitable for functions of respective parts by imparting multiple layers having different thermal conductivity on the surface of the cylinder liner for insert casting, such that the cylinder liner can be used for vehicle cylinder blocks.