Abstract: A ferrous piston for gasoline powered engines having dimensions which achieve reduced mass and improved performance is provided. The piston crown has a thickness of less than 4 mm and includes valve pockets with an axial clearance between the valve pockets and an uppermost ring groove of less than 1.5 mm. The pin bosses have an axial thickness of less than 3.7% of a bore diameter, which is the largest outer diameter of the piston, measured between a pin bore and the crown at 1 mm from an inner face forming the pin bore. Each pin boss has a radial thickness of less than 3% of the bore diameter measured between the pin bore and a lower end of the pin boss. An undercrown surface presents a projected area of less than 45% of a total piston bore area, wherein the total piston bore area is ?BD2/4, BD being the bore diameter.

Abstract: A ferrous piston for gasoline powered engines having dimensions which achieve reduced mass and improved performance is provided. The piston crown has a thickness of less than 4 mm and includes valve pockets with an axial clearance between the valve pockets and an uppermost ring groove of less than 1.5 mm. The pin bosses have an axial thickness of less than 3.7% of a bore diameter, which is the largest outer diameter of the piston, measured between a pin bore and the crown at 1 mm from an inner face forming the pin bore. Each pin boss has a radial thickness of less than 3% of the bore diameter measured between the pin bore and a lower end of the pin boss. An undercrown surface presents a projected area of less than 45% of a total piston bore area, wherein the total piston bore area is ?BD2/4, BD being the bore diameter.

Abstract: A ferrous piston for gasoline powered engines having dimensions which achieve reduced mass and improved performance is provided. The piston crown has a thickness of less than 4 mm and includes valve pockets with an axial clearance between the valve pockets and an uppermost ring groove of less than 1.5 mm. The pin bosses have an axial thickness of less than 3.7% of a bore diameter, which is the largest outer diameter of the piston, measured between a pin bore and the crown at 1 mm from an inner face forming the pin bore. Each pin boss has a radial thickness of less than 3% of the bore diameter measured between the pin bore and a lower end of the pin boss. An undercrown surface presents a projected area of less than 45% of a total piston bore area, wherein the total piston bore area is ?BD2/4, BD being the bore diameter.

Abstract: A piston including an abradable coating applied to a round surface of the piston is provided. The shape of the round surface is not greater than 0.1 mm from a circular shape, and thus is relatively inexpensive to machine. As the piston reciprocates in an internal combustion engine, the abradable coating rubs against another component, such as a cylinder liner or wrist pin, to achieve suitable contact geometry, such as an oval, asymmetric, or other non-round shape. Thus, a costly machining process is not required to achieve the desired contact geometry. The abradable coating can also be applied to ring lands, skirt sections, or along pin bores of the piston. The abradable coating can also be applied to a wrist pin or an opening of a connecting rod which receives the wrist pin. The abradable coating can be formed from a polymer-based material or an aluminum-silicon alloy-based material.

Abstract: A ferrous piston for gasoline powered engines having dimensions which achieve reduced mass and improved performance is provided. The piston crown has a thickness of less than 4 mm and includes valve pockets with an axial clearance between the valve pockets and an uppermost ring groove of less than 1.5 mm. The pin bosses have an axial thickness of less than 3.7% of a bore diameter, which is the largest outer diameter of the piston, measured between a pin bore and the crown at 1 mm from an inner face forming the pin bore. Each pin boss has a radial thickness of less than 3% of the bore diameter measured between the pin bore and a lower end of the pin boss. An undercrown surface presents a projected area of less than 45% of a total piston bore area, wherein the total piston bore area is ?BD2/4, BD being the bore diameter.

Abstract: A piston including an abradable coating applied to a round surface of the piston is provided. The shape of the round surface is not greater than 0.1 mm from a circular shape, and thus is relatively inexpensive to machine. As the piston reciprocates in an internal combustion engine, the abradable coating rubs against another component, such as a cylinder liner or wrist pin, to achieve suitable contact geometry, such as an oval, asymmetric, or other non-round shape. Thus, a costly machining process is not required to achieve the desired contact geometry. The abradable coating can also be applied to ring lands, skirt sections, or along pin bores of the piston. The abradable coating can also be applied to a wrist pin or an opening of a connecting rod which receives the wrist pin. The abradable coating can be formed from a polymer-based material or an aluminum-silicon alloy-based material.

Abstract: A piston formed from an Al—Si alloy having an average Si composition includes a high wear region having a surface that is Si-rich with respect to the average Si composition of the Al—Si alloy. The surface of the predetermined high wear region is treated, as by etching, to selectively remove Al from the surface to produce the Si-rich region. The Si-rich region has improved resistance to wear. The piston may be treated to produce one or more high wear regions which are Si-rich with respect to the average Si composition of the alloy. High wear regions may include the annular grooves for receiving a piston ring, the piston skirt and the pin bore.

Abstract: A piston formed from an Al alloy, such as an Al—Si alloy, has wear resistant coating applied to a predetermined portion of the outer surface. The predetermined portion of the outer surface preferably includes the piston skirt. The coating includes an adhesion promoting primer layer of a silane and a polymer coating layer. The silane primer coating promotes adhesion between the Al-alloy and the polymer coating.