Abstract: A cylinder head includes a pair of side walls extending along a cylinder arrangement direction, a connection wall that is provided between the pair of side walls and connects both of the side walls with each other, a bearing part provided in the connection wall, an intake port that is open in one side wall out of the pair of side walls, and an exhaust port that is open in the other side wall. The other side wall is provided with a protrusion part that projects from the other side wall, extends along the cylinder arrangement direction, and has a confronting surface that faces an exhaust pipe connected with the other side wall.

Abstract: A water jacket spacer is inserted into a water jacket. The water jacket spacer includes an expansion member, a plate-shaped holder to which the expansion member is fixed, and a leaf spring that abuts the inner wall of the water jacket. The leaf spring projects from a face on the holder on the side opposite of the expansion member. The holder curves to match the shape of the water jacket. The position of the water jacket spacer in the water jacket is maintained by the biasing force of the leaf spring.

Abstract: A cylinder head includes a pair of side walls extending along a cylinder arrangement direction, a connection wall that is provided between the pair of side walls and connects both of the side walls with each other, a bearing part provided in the connection wall, an intake port that is open in one side wall out of the pair of side walls, and an exhaust port that is open in the other side wall. The other side wall is provided with a protrusion part that projects from the other side wall, extends along the cylinder arrangement direction, and has a confronting surface that faces an exhaust pipe connected with the other side wall.

Abstract: A cylinder liner for insert casting and a method for manufacturing the cylinder liner are provided. The cylinder liner and the method are applied to cylinder blocks and improve the adherence and the bonding strength with a cylinder block material in a favorable manner. The cylinder liner satisfies the following requirements: (i) the height of projections 1P is in a range between 0.5 mm and 1.0 mm, inclusive; (ii) the number of the projections 1P is in a range between 5 and 60, inclusive, per cm2 on the outer circumferential surface; (iii) the area ratio of regions each encircled by a contour line of a height of 0.4 mm is in a range between 10% and 50%, inclusive; (iv) the area ratio of regions each encircled by a contour line of a height of 0.2 mm is in a range between 20% and 55%, inclusive; (v) the region each encircled by a contour line of the height of 0.4 are independent from each other; and (vi) the area of the regions each encircled by a contour line of the height of 0.4 mm is in a range between 0.

Abstract: A cylinder liner for insert casting and a method for manufacturing the cylinder liner are provided. The cylinder liner and the method are applied to cylinder blocks and improve the adherence and the bonding strength with a cylinder block material in a favorable manner. The cylinder liner satisfies the following requirements: (i) the height of projections 1P is in a range between 0.5 mm and 1.0 mm, inclusive; (ii) the number of the projections 1P is in a range between 5 and 60, inclusive, per cm2 on the outer circumferential surface; (iii) the area ratio of regions each encircled by a contour line of a height of 0.4 mm is in a range between 10% and 50%, inclusive; (iv) the area ratio of regions each encircled by a contour line of a height of 0.2 mm is in a range between 20% and 55%, inclusive; (v) the region each encircled by a contour line of the height of 0.4 are independent from each other; and (vi) the area of the regions each encircled by a contour line of the height of 0.4 mm is in a range between 0.

Abstract: A cylinder block includes an inner block member having a cylinder liner portion and an outer block member having a cylinder outer wall portion. With the inner and outer block members assembled together, a water jacket is defined between the outer and inner circumferential surface. A first sealing surface of the cylinder liner portion is opposed to a second sealing surface of the cylinder outer wall portion below the water jacket, and a liquid gasket is provided between the first and second sealing surfaces. A continuous projection is provided on the first sealing surface. When the cylinder liner portion is inserted into the space defined by the cylinder outer wall portion, the projection prevents the gasket from being displaced to a trailing side on the cylinder liner portion with respect to the inserting direction. As a result, the clearance between the block members is sealed reliably.

Abstract: A cylinder block for an engine has a cylinder assembly having a plurality of cylinders, each corresponding to one of a plurality of pistons. A block body has an outer wall accommodating the cylinder assembly, a crankcase accommodating the crankshaft, and a plurality of partitions. The partitions divide the space in the crankcase into a plurality of crank chambers. The number of the crank chambers corresponds to the number of the cylinders. The outer wall, the crankcase, and the partitions are formed integrally. A partition through portion is formed in a predetermined one of the partitions to connect an adjacent pair of the crank chambers. The partition through portion opens toward the cylinders.

Abstract: A cylinder block for an engine has a cylinder assembly having a plurality of cylinders, each corresponding to one of a plurality of pistons. A block body has an outer wall accommodating the cylinder assembly, a crankcase accommodating the crankshaft, and a plurality of partitions. The partitions divide the space in the crankcase into a plurality of crank chambers. The number of the crank chambers corresponds to the number of the cylinders. The outer wall, the crankcase, and the partitions are formed integrally. A partition through portion is formed in a predetermined one of the partitions to connect an adjacent pair of the crank chambers. The partition through portion opens toward the cylinders.

Abstract: A cylinder block includes an inner block member having a cylinder liner portion and an outer block member having a cylinder outer wall portion. With the inner and outer block members assembled together, a water jacket is defined between the outer and inner circumferential surface. A first sealing surface of the cylinder liner portion is opposed to a second sealing surface of the cylinder outer wall portion below the water jacket, and a liquid gasket is provided between the first and second sealing surfaces. A continuous projection is provided on the first sealing surface. When the cylinder liner portion is inserted into the space defined by the cylinder outer wall portion, the projection prevents the gasket from being displaced to a trailing side on the cylinder liner portion with respect to the inserting direction. As a result, the clearance between the block members is sealed reliably.

Abstract: A cylinder block production method is characterized by having, as a step prior to a cast-enclosing step of cast-enclosing a cast iron-made cylinder liner within a cylinder block body, an erosion-wash step of washing an outer peripheral wall surface of the cylinder liner and eroding a portion of a base structure of the cast iron forming the outer peripheral wall surface of the cylinder liner so as to form many small protrusions on the outer peripheral wall surface by jetting a high-pressure fluid onto the outer peripheral wall surface of the cylinder liner, in order to improve strength of adhesion between the cylinder liner and the cylinder block body. Since the base structure is partially eroded, complicated-shape small protrusions can be formed. Furthermore, sand and a mold release agent adhering to the outer peripheral wall surface of the cylinder liner can be removed. Therefore, the adhesion strength will improve.

Abstract: A gasket has seal portions at portions contacting peripheries of upper end portions of internal surfaces of cylinders, respectively. By being provided with a stopper, each of the seal portions is formed as a thick portion in the gasket. The stopper of each of the seal portions has a portion whose thickness is greater than a thickness of the stopper of each of the seal portions corresponding to cylinders at both ends of the cylinder alignment.

Abstract: A cylinder block production method is characterized by having, as a step prior to a cast-enclosing step of cast-enclosing a cast iron-made cylinder liner within a cylinder block body, an erosion-wash step of washing an outer peripheral wall surface of the cylinder liner and eroding a portion of a base structure of the cast iron forming the outer peripheral wall surface of the cylinder liner so as to form many small protrusions on the outer peripheral wall surface by jetting a high-pressure fluid onto the outer peripheral wall surface of the cylinder liner, in order to improve strength of adhesion between the cylinder liner and the cylinder block body. Since the base structure is partially eroded, complicated-shape small protrusions can be formed. Furthermore, sand and a mold release agent adhering to the outer peripheral wall surface of the cylinder liner can be removed. Therefore, the adhesion strength will improve.