A piston for an opposed-piston, internal combustion engine includes a crown with an end surface having a bowl shaped to form a combustion chamber with an end surface of an opposing piston in the opposed-piston engine. A substantially circumferential top land of the crown meets the end surface at a substantially circular peripheral edge, and a skirt comprising a sidewall extends from a substantially circumferential belt region of the crown. A wristpin bore with a wristpin axis opens through the sidewall. The end surface of the piston includes a pair of injection regions across which fuel is injected into the bowl. The injection regions are disposed in substantially diametrically-opposed quadrants of the end surface which are defined by the wristpin axis and a connecting rod envelope axis substantially orthogonal to the wristpin axis. Each injection region extends along a respective arc concentric with the substantially circular peripheral edge.

Disclosed are novel bridged bi-aromatic phenol ligands and transition metal catalyst compounds derived therefrom. Also disclosed are methods of making the ligands and transition metal compounds, and polymerization processes utilizing the transition metal compounds for the production of olefin polymers.

An improved piston forging for use in an internal combustion engine is disclosed. The piston forging comprises a crown, a pair of pin towers extending generally axially away from the crown, and a skirt extending generally axially away from the crown. The improved piston forging further comprises a plurality of grains flowing across the piston forging. The plurality of grains are reoriented during the forging operation into a configuration that follows the surfaces and features of the piston forging. More specifically, the plurality of grains are reoriented in a manner that is most beneficial to resist combustion and inertial forces that are enacted upon a machined piston during operation.

Piston (1) of an internal combustion engine, which piston is designed in structured construction, comprising two oppositely arranged load-bearing skirt wall portions (2), wherein a connecting wall (3) respectively extends, starting from a pin boss (4), in the direction of the side edge of the load-bearing skirt wall portions (2), characterized in that in an interior of the piston (1) is (are) disposed at least one rib (5, 6, 7), preferably three ribs (5, 6, 7), and the material of the regions around the at least one rib (5, 6, 7) is reduced.

A piston, particularly a piston for use in a diesel engine, particularly a heavy duty diesel engine, is formed from a billet of metal, such that the finished piston has a mass that is at least 50%, and, more preferably, up to about 62%, of the mass of the billet. Other than finishing steps, the piston is formed with a closed gallery, without loss of mass through machining processes.

A piston for an internal combustion engine includes a piston upper part and a piston lower part having a cooling channel including at least one inlet opening. A dam-type elevation is formed in the region of the at least one inlet opening through forging of the dam elevation in the cooling channel portion in the piston lower part. In one example, a funnel-shaped inlet contour is formed in the inlet opening by pre-forging. In one example, a V-shaped element is formed in the piston upper part cooling chamber portion in alignment with the inlet opening and used as a coolant jet splitter.

A galleryless piston and method of construction provide a piston body forged from a single piece of material having an upper combustion surface extending around a longitudinal center axis along which the piston reciprocates for exposure to a combustion chamber of an internal combustion engine. The upper combustion surface has an asymmetric geometry relative to a center plane extending along the central longitudinal axis in generally perpendicular relation to a pin bore axis.

A method for producing a piston for an internal combustion engine may include the steps of: producing a first blank corresponding to a piston main body via a deformation process; producing a second blank corresponding to a piston ring part via at least one of a deformation process and a casting process; pre-machining the first blank and the second blank, and finishing a welding surface of the first blank and a welding surface of the second blank via machining; connecting the first blank and the second blank via welding the welding surface of the first blank to the welding surface of the second blank to form a piston body; and performing at least one of a secondary machining process and a finish machining process on the piston body to produce the piston.

A piston, particularly a piston for use in a diesel engine, particularly a heavy duty diesel engine, is formed from a billet of metal, such that the finished piston has a mass that is at least 50%, and, more preferably, up to about 62%, of the mass of the billet. Other than finishing steps, the piston is formed with a closed gallery, without loss of mass through machining processes.

A method for producing a piston of an internal combustion engine, with a cooling duct, may include producing a piston blank with a cooling duct, closing an inlet and an outlet of the cooling duct by at least one closure element, machine-finishing the piston blank, and removing the at least one closure element.