Methods and systems are provided for filling surface pores of a cylinder inner surface coating with one or more fill materials to provide desired material and performance properties. In one example, a cylinder for an engine includes an inner surface including a coating having a plurality of surface pores, at least a portion of the plurality of surface pores filled with one or more fill materials, the one or more fill materials configured to decrease friction, increase tribofilm formation, adjust heat transfer, decrease material deposit, and/or decrease run-in duration.

Components for reducing oil sticking on surfaces of an internal combustion engine are disclosed. The engine may include an engine block with a piston cylinder, a piston moveable in reciprocal motion within the piston cylinder, and a cylinder head mounted on the engine block. The engine block, the cylinder head, and the piston may define a combustion chamber. The engine may include an intake conduit mounted to the cylinder head, an intake valve port defined by the cylinder head, and an intake valve mounted in reciprocally movable fashion to the cylinder head for placing the intake valve port in fluid communication with the combustion chamber. The engine may include a first oleophobic coating provided on portions of the intake valve, and a valve seat insert secured to the cylinder head. The valve seat insert may define an oil passage in fluid communication with the intake valve port.

Components for reducing oil sticking on surfaces of an internal combustion engine are disclosed. The engine may include an engine block with a piston cylinder, a piston moveable in reciprocal motion within the piston cylinder, and a cylinder head mounted on the engine block. The engine block, the cylinder head, and the piston may define a combustion chamber. The engine may include an intake conduit mounted to the cylinder head, an intake valve port defined by the cylinder head, and an intake valve mounted in reciprocally movable fashion to the cylinder head for placing the intake valve port in fluid communication with the combustion chamber. The engine may include a first oleophobic coating provided on portions of the intake valve, and a valve seat insert secured to the cylinder head. The valve seat insert may define an oil passage in fluid communication with the intake valve port.

A cylinder liner for an internal combustion engine may have a running surface, in which by honing directed honing grooves may be introduced. The running surface may have a first region and a second region, wherein the first region may have a roughness that may be distinct from a roughness of the second region. A transition between the first region and the second region may proceed obliquely to a cylinder longitudinal axis at least in some portions. At least some of the honing grooves at the transition between the first region and the second region are uninterrupted.

In a sliding structure for an internal combustion, a cylinder has recesses in a stroke center region. Piston rings have inclined surfaces on an outer circumferential surface, and a lubricating oil flows between the inner wall surface and the outer circumferential surface that relatively move via the inclined surfaces. At any RPM equal to or greater than at idle, a center friction coefficient at the stroke center region through which the piston rings pass at the highest speed is less than a center friction coefficient when no recesses are formed in the stroke center region. Contrarily, at the RPM, an outside friction coefficient when the piston rings pass through a region outside the stroke center region is less than an outside friction coefficient when the recesses are formed in the outside region. As a result, further improved low fuel efficiency is achieved for the dimple liner technique.

In a sliding structure for an internal combustion, a cylinder has recesses in a stroke center region. Piston rings have inclined surfaces on an outer circumferential surface, and a lubricating oil flows between the inner wall surface and the outer circumferential surface that relatively move via the inclined surfaces. At any RPM equal to or greater than at idle, a center friction coefficient at the stroke center region through which the piston rings pass at the highest speed is less than a center friction coefficient when no recesses are formed in the stroke center region. Contrarily, at the RPM, an outside friction coefficient when the piston rings pass through a region outside the stroke center region is less than an outside friction coefficient when the recesses are formed in the outside region. As a result, further improved low fuel efficiency is achieved for the dimple liner technique.

There is provided a lubrication structure of an internal combustion engine. A transmission chamber is arranged adjacently at the rear of a crank chamber. An oil chamber communicates with a bottom part of the transmission chamber. A feed pump supplies oil in the oil chamber to a lubrication target part. A scavenging pump sucks the oil in the crank chamber and discharges the oil to the transmission chamber. The feed pump and the scavenging pump are arranged coaxially in a width direction of the internal combustion engine. At least a part of the scavenging pump is arranged higher than a lower end of the crank chamber. A rear end of the scavenging pump is arranged at the same position as a rear end of the crank chamber or in front of the rear end of the crank chamber in a front and rear direction.

There is provided a lubrication structure of an internal combustion engine. A transmission chamber is arranged adjacently at the rear of a crank chamber. An oil chamber communicates with a bottom part of the transmission chamber. A feed pump supplies oil in the oil chamber to a lubrication target part. A scavenging pump sucks the oil in the crank chamber and discharges the oil to the transmission chamber. The feed pump and the scavenging pump are arranged coaxially in a width direction of the internal combustion engine. At least a part of the scavenging pump is arranged higher than a lower end of the crank chamber. A rear end of the scavenging pump is arranged at the same position as a rear end of the crank chamber or in front of the rear end of the crank chamber in a front and rear direction.

A member having a sliding contact surface that exerts a reduced frictional force when making sliding contact with a prescribed member and retains the lubricating oil more uniformly is provided. The sliding contact surface is a honed surface having flat plateau parts and groove parts. As calculated in regard to the sliding contact surface by using a mean line derived from a cross-sectional curve of the sliding contact surface in accordance with ISO 13565-1, a ten-point average roughness is 0.6-7.0 m, a load length ratio at a cut level of 20% is 60-98%, an effective load roughness is 0-1 m, and a mean value of intervals between the groove parts having a depth of 0.2 m or greater from the mean line is 79-280 m.

A member having a sliding contact surface that exerts a reduced frictional force when making sliding contact with a prescribed member and retains the lubricating oil more uniformly is provided. The sliding contact surface is a honed surface having flat plateau parts and groove parts. As calculated in regard to the sliding contact surface by using a mean line derived from a cross-sectional curve of the sliding contact surface in accordance with ISO 13565-1, a ten-point average roughness is 0.6-7.0 m, a load length ratio at a cut level of 20% is 60-98%, an effective load roughness is 0-1 m, and a mean value of intervals between the groove parts having a depth of 0.2 m or greater from the mean line is 79-280 m.