A piston and process for manufacturing a piston includes an upper part providing an upper combustion surface including a top land, a land ring and a combustion bowl. An undercrown surface is formed under the combustion bowl. A lower part including pin bosses and a piston skirt are formed under the undercrown surface. At least one of the upper part and the lower part are formed with metal injection molding.

One of the processes needed for the conversion of a diesel engine so that it can use natural gas as fuel is the reduction of the compression ratio, since the one that the diesel engine originally has is greater than the one needed for the optimal operation with natural gas. The proposed process consists of adding cold material to the cylinder head or engine head through metallization or electric arc or plasma spraying to form a combustion chamber therein.

A piston with a cooling gallery containing an open cell radiator is provided. The radiator has a large thermally conductive surface area that acts as a heat-sink to remove heat from the piston. Heat from the piston is transmitted from the radiator to cooling oil that enters the cooling gallery via an oil inlet formed in a floor of the cooling gallery and exits the cooling gallery via an oil outlet. The piston comprises a piston body including an upper part presenting an upper combustion surface and an undercrown surface. A ring belt depends from the upper combustion surface, and the cooling gallery extends around the piston body beneath the undercrown surface radially inwardly of the ring belt. The radiator includes a plurality of fins extending annularly around the cooling gallery. The fins of the radiator are spaced from one another by gaps extending annularly around the cooling gallery.

A piston crown for a piston of a pair of pistons in a two-stroke, opposed-piston, compression ignition combustion engine has a barrier layer and a conductive layer. The barrier layer at least partially surrounds a combustion chamber formed by the piston crown and an end surface of an opposing piston. The conductive layer connects the crown to the rest of the piston body. The barrier layer and the conductive layer are joined either through welding or through the fabrication process. Optionally, the piston crown includes an insulating layer between the barrier and conductive layers.

A marine engine comprises a cylinder block that defines a cylinder bore; a piston that reciprocates in the cylinder bore under force of combustion in the marine engine; and a liner disposed in the cylinder bore between the piston and the cylinder block. The liner provides a running surface for the piston. The liner has a cylindrical liner body that is sized to fit snugly within the cylinder bore and a pair of diametrically opposing tabs axially extends from liner body into the cylinder bore. Methods of making a marine engine are also disclosed.

A piston including a piston crown, the piston crown defining a combustion bowl with a bowl base and bottom surface. A failure initiation structure is provided on the bottom surface of the combustion bowl to initiate favorable fracture at predetermined loads. Such favorable fracture may lead to the a separation of a fragment of the bowl base from the combustion bowl when a predetermined load or pressure is exceeded within the combustion bowl.

Disclosed is a cylinder liner having a high bonding strength to a cylinder block. Further disclosed is a method for producing the same. The cylinder liner uses a silicon-aluminum alloy as a material; a plurality of protrusions are formed on the external surface thereof; and the protrusions each contain a pillar section extending from the external surface, and a head section formed at the end of the pillar section.

A method for bonding a cylinder liner within a cylinder bore of a vehicle engine block includes providing a bonding substrate on one of an outside surface of the cylinder liner and an inside surface of a cylinder bore in the engine block, positioning the cylinder liner in the cylinder bore, and heating the cylinder liner.

A machinery casing portion for an engine, the machinery casing portion having a first sealing face configured to engage a second sealing face of a second machinery casing portion so as to form a sealed joint therebetween in an assembled configuration, the machinery casing portion comprising: a recess configured to receive a sealant, the recess being provided adjacent to the first sealing face; and at least one opening configured to receive a fastener, wherein the opening at least partially extends into a wall of the recess.

A method of coating an inner surface of an engine cylinder bore includes cleaning the surface to remove carbon, resulting in the surface having a maximum of 30 atomic percent carbon, texturing the surface to achieve a developed interfacial area ratio of at least 100%, and heating the surface to between 100-200 degrees Celsius. A thermal spray coating is then adhered to the surface. In some cases, a force of 25+ Newtons scratched across the thermal spray coating is required to remove the thermal spray coating from the surface. Maximum adhesion strength is achieved when the coating is applied to: 1) a heated surface that has 2) an Sdr of at least 100% and 3) a maximum of 20 atomic percent of carbon on the surface. When these three criteria are all present, adhesion strength can be 50 Newtons or more with evidence of metallurgical diffusion/bonding at the interface.