An object of the present invention is to enhance the thermal efficiency of an engine, to provide a film having low thermal conductivity and low heat capacity and being free from separation, drop-off and the like and excellent in durability and reliability. According to the present invention, an engine combustion chamber structure, wherein an anodic oxide film having a thickness of from more than 20 μm to 500 μm and a porosity of 20% or more is formed on the inner surface of the engine combustion chamber, and a manufacturing method thereof are provided.

An object of the present invention is to enhance the thermal efficiency of an engine, to provide a film having low thermal conductivity and low heat capacity and being free from separation, drop-off and the like and excellent in durability and reliability. According to the present invention, an engine combustion chamber structure, wherein an anodic oxide film having a thickness of from more than 20 μm to 500 μm and a porosity of 20% or more is formed on the inner surface of the engine combustion chamber, and a manufacturing method thereof are provided.

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.

In a method for coating a sliding element, in particular a piston ring or a cylinder liner of an internal combustion engine, DLC phases are embedded into a hard material layer as said hard material layer is deposited. A sliding element, such as a piston ring or a cylinder liner of an internal combustion engine, comprises a hard material layer with embedded DLC phases.

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.

The overhead camshaft engine (10) includes a cylinder block (11), a crankcase (12) attached to a lower part of the cylinder block to define a crankcase chamber (32), a bearing retaining member (60) attached to a part of the cylinder block, a crankshaft (20) rotatably supported by a pair of bearings (21, 22) supported by the cylinder block and the bearing retaining member, respectively, and a crankshaft pulley (53) attached to a part of the end of the crankshaft projecting outward from the bearing supported by the bearing retaining member.

In an overhead cam engine (10) having a first bearing (21) supported by the cylinder block (11), and a second bearing (22) supported by a bearing retaining member (60) attached to the cylinder block inside a crankcase chamber (12) for rotatably supporting a crankshaft (20), the crankshaft is provided with a reduced diameter portion (24b) having a smaller outer diameter than an adjoining part of the crankshaft on a side of the second bearing facing away from a cylinder (15) defined in the cylinder block, and a crankshaft pulley (53) is mounted on the reduced diameter portion.

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.