An anti-polishing ring includes a ring body defining an axis of revolution, and a radial direction that is perpendicular to the axis of revolution, and a circumferential direction about the axis of revolution. The ring body includes an outer circumferential surface, a bottom surface, a top surface, and an inner circumferential surface. The inner circumferential surface defines an inner diameter, the ring body defines a radial thickness measured from the inner circumferential surface to the outer circumferential surface, and a ratio of the radial thickness to the inner diameter ranges from 0.015 to 0.020.

A piston ring set for internal combustion (IC) engine is provided. The IC engine includes a cylinder having a liner and a finish on the liner. A piston having a crown and a set of grooves is disposed in the cylinder. A set of piston rings is disposed in the set of grooves. The piston rings are disposed in order from closest to the crown and include at least a first compression ring having free ends defining a first end gap, a second compression ring having free ends defining a second end gap. A nominal value of the first end gap of the first compression ring is greater than a nominal value of the second end gap of the second compression ring.

A cylinder liner for an internal combustion engine may include an outer circumferential surface defined by the cylinder liner composed of a gray cast iron for integrally casting onto a cast material of an engine block. A bonding component may be included for strengthening a bond of the outer circumferential surface to the cast material of the engine block. The bonding component may include at least one of a wire mesh and a wire grid that does not melt during a casting operation of the engine block. The bonding component may be arranged at least in a predefined region on the outer circumferential surface. The bonding component may be welded at least partially to the outer circumferential surface.

An engine having a water jacket may include a cylinder block in which cylinder liners forming a combustion chamber may be disposed from a first end to a second end of the cylinder block, and a block water jacket may be formed around the cylinder liners, a cylinder head having a head water jacket coupled to a top of the cylinder block, receiving cooling water from an exhaust side of the block water jacket and discharging cooling water to an intake side of the block water jacket, and inserts that may be inserted into the block water jacket and that may have horizontal dividing blades dividing the block water jacket into upper and lower parts, legs extending downward from the horizontal dividing blades, and flow preventing protrusions protruding upward from the horizontal dividing blades to divide the upper part of the block water jacket.

A cast iron having high strength, hardness, and thermal conductivity for a cylinder liner of an internal combustion engine is provided. The cast iron includes 3.2 wt. % to 3.8 wt. % carbon, 2.2 wt. % to 3.2 wt. % silicon, 0.5 wt. % to 1.3 wt. % copper, and at least 75.0 wt. % iron, based on the total weight of the cast iron. The cast iron further includes 0.01 wt. % to 0.5 wt. % manganese, 0.01 wt. % to 0.2 wt. % chromium, up to 0.3 wt. % phosphorous, up to 0.05 wt. % sulfur, up to 0.2 wt. % tin, and up to 0.1 wt. % magnesium, based on the total weight of the cast iron. Preferably, the cast iron is free of molybdenum, nickel, and vanadium. The cast iron is also heat treated and solidifies to achieve fully spheroidal graphite.

A coated cylinder liner 20 comprises a wear resistant layer 22, such as a DLC coating, and a metallic adhesive layer 24, such as chromium or titanium, deposited on an inner surface 26 thereof. The layers 22, 24 each have a thickness t.sub.w, t.sub.a varying by not more than 5% along at least 70% of the length of the inner surface 26. The metallic adhesive layer 24 is deposited by sputtering a consumable metallic electrode 28 onto the inner surface 26. The sputtering can be magnetron sputtering. The consumable metallic electrode 28 can include a hollow opening 40 with orifices 50 for providing a carrier gas into the deposition chamber 52. In addition, the inner surface 26 of the cylinder liner 20 can provide the deposition chamber 52 by sealing a first opening 36 and second opening 38 of the cylinder liner 20.

Engine blocks and methods of forming the same are disclosed. The engine block may comprise a body including at least one cylindrical engine bore wall having a longitudinal axis and including a coating extending along the longitudinal axis and having a coating thickness. The coating may have a middle region and first and second end regions, and a plurality of pores may be dispersed within the coating thickness. The middle region may have a different average porosity than one or both of the end regions. The method may include spraying a first porosity coating in a middle longitudinal region of the bore and spraying a second porosity coating in one or more end regions of the bore. The first porosity may be greater than the second porosity and the first and second porosities may be formed during the spraying steps. The pores may act wells for lubricant.

There is provided a cylinder device having optimal arrangement of fine textures and optimal surface roughness capable of reducing wear of a cylinder bore side and a piston ring by processing fine textures in an optimal selection region of the cylinder bore side to improve lubrication characteristics between the piston ring and the cylinder bore side while reducing engine oil consumption by processing surface roughness of the cylinder bore side to an optimal status.

A cylinder liner for insertion into an aluminum internal-combustion engine block may include a cylindrical body of cast iron having a circumferential external surface. The cylinder liner may also have a coating deposited on and surrounding the external surface. The external surface may have a specific roughness, and the coating may include at least 98% by volume of pure nickel, and a remainder composed of impurities.

To provide a surface structure of an aluminum-based member which can further improve heat insulating properties and heat shielding properties of the aluminum-based member. In an aluminum-based member 1 containing at least a silicon composition, a porous oxide film 2 is provided on a surface of the aluminum-based member 1, and the oxide film 2 is constituted to have at least a pore 2a extending from the surface toward an inside in a thickness direction of the oxide film 2 and a void 3a present inside the silicon composition 3 extending in a direction substantially orthogonal to the thickness direction of the oxide film 2.