Abstract: A piston for an internal combustion engine comprising a piston body having a crown adjacent a skirt. Any of an outer crown surface of the crown, piston ring grooves in the crown, and/or the crown include a steel H11 alloy and/or a steel H13 alloy. The steel H11 or H13 material is applied in any technique such as a piston crown coating/cladding, fused overlay, powder cladding, welded on an outer crown surface of the crown, and/or included in the crown and/or skirt of a monolithic piston. The steel H11 or H13 material is applied with an additive manufacturing item, applied with a coating, buttering, or other surface modification to facilitate joining to the piston body. The application of the steel H11 or H13 material with a heat treatment to at least the piston crown creates an elevated temperature oxidation resistant high performance piston.

Abstract: Pistons and/or piston rings include features to provide oil and/or gas flow past the piston rings of the piston. As a result, oil consumption due to reverse blow-by conditions is reduced or eliminated.

Abstract: An engine cylinder piston connecting rod subassembly, for use in an engine, includes a piston (53), a piston pin (52) and a connecting rod (51). The connecting rod has a piston end portion with a piston pin bore (62). The piston pin is inserted through the piston pin bore and oppositely disposed portions of the piston, for securing the piston and the connecting rod together. Opposite ends of the piston pin bore are machined or profiled with relief portions (60, 61), to allow for piston pin deflection and thereby maximize the load carrying capacity, by providing a greater area of contact. The relief portions can be a curved surface (65) machined as part of the bore, or a plurality of end-to-end angled frustoconical surfaces (66a, 66b, 66c). The relief portions are shaped to correspond to the shape of the corresponding piston pin when under load during normal engine operation.