Abstract: A piston for an internal combustion engine is provided. The piston includes an open inner cooling area in which the undercrown surface is exposed, and an annular outer cooling gallery. The piston also includes an oil outlet scoop for local cooling of the undercrown surface of the piston. The outer cooling gallery includes an oil outlet opening, and the oil outlet scoop is beneath and vertically aligned with the oil outlet opening. The oil outlet scoop includes a concave surface facing the oil outlet opening. During operation, oil exits the oil outlet opening, and the oil outlet scoop catches the exiting oil and directs the oil to the inner cooling area and the exposed undercrown surface.

Abstract: A piston and method of construction are provided. The piston includes an upper crown having a combustion surface with an upper land depending therefrom and a lower crown having a pair of pin bosses that depend to a pair of laterally spaced, axially aligned pin bores. The upper crown is constructed as a monolithic piece of a first material having a thermal conductivity within a range of about 7 to 25 W/m-K. The lower crown is constructed from a low grade steel material having a thermal conductivity higher than the upper crown. The upper crown is joined directly to the lower crown, wherein the upper crown acts as a barrier to thermal conductivity and thus, the heat within a combustion chamber housing the piston for reciprocation therein is maintained and maximized.

Abstract: A piston and method of construction are provided. The piston includes an upper crown having a combustion surface with an upper land depending therefrom and a lower crown having a pair of pin bosses that depend to a pair of laterally spaced, axially aligned pin bores. The upper crown is constructed as a monolithic piece of a first material having a thermal conductivity within a range of about 7 to 25 W/m-K. The lower crown is constructed from a low grade steel material having a thermal conductivity higher than the upper crown. The upper crown is joined directly to the lower crown, wherein the upper crown acts as a barrier to thermal conductivity and thus, the heat within a combustion chamber housing the piston for reciprocation therein is maintained and maximized.

Abstract: A piston assembly for heavy duty diesel engine applications comprises a piston having pin bosses formed with pin bores for the accommodations of a wrist pin. The wrist pin is fabricated of steel and is extendable through the small end bore of a steel connecting rod and the bores of the piston body for coupling the piston body to the connecting rod. In lieu of a conventional Cu—Pb—Sn bushing usually pressed into the small end bore, a coating of manganese phosphate is applied to either the pin or small end bore of the connecting rod and pin bosses to provide the necessary tribological properties therebetween. The porous coating absorbs and entraps lubricating oil, creating a still lubricant squeeze film between the steel running surfaces under heavy load.