Provided are a method of manufacturing an engine, an engine, and a connected cylinder. The method of manufacturing an engine includes at least a fitting step of fitting a connected cylinder to a hollow portion of a cylinder block main body. The connected cylinder is (1) a first connected cylinder including two or more cylinder liners and a connecting portion configured to connect the two or more cylinder liners to each other or (2) a second connected cylinder including a connected cylinder main body portion having two or more cylinder bores and a coating configured to cover an inner peripheral surface of the connected cylinder main body portion in which the cylinder bores are formed. The cylinder block main body has one end side, another end side, and the hollow portion passing through the cylinder block main body from the one end side to the another end side.

Provided is a spacer configured such that a protruding portion remaining after removal of a portion unnecessary after molding does not contact an inner wall of a coolant water flow path and therefore, even a portion of the spacer in the vicinity of the remaining portion can be positioned close to the cylinder bore side inner wall. The spacer of this embodiment is a spacer (4) formed of a resin molded body and inserted, in use, into a coolant water flow path (3) through an opening (30) of the coolant water flow path (3) that is formed around a plurality of cylinder bores (2) formed adjacent to each other in a cylinder block (1) of an internal combustion engine. The spacer (4) includes a spacer body (40) formed in a cylindrical shape to surround the cylinder bores (2), and a protruding remaining portion (5) remaining after removal of a portion (6ba) necessary in molding and unnecessary after molding. The remaining portion (5) is formed at an end surface (44a) positioned on a side close to the opening (30) of the spacer body (40).

It is described herein a cylinder sleeve assembly for an engine. The cylinder sleeve assembly may comprise a plurality of cylinder sleeves and a plurality of junctures. Each cylinder sleeve of the plurality of cylinder sleeves may comprise an outer cylinder sleeve wall, and an inner cylinder sleeve wall. Each juncture of the plurality of junctures connects two adjacent cylinder sleeves of the plurality of cylinder sleeves.

A cylinder block for use in an internal combustion engine includes a first and second cylinder bores, a first and second cylinder bore liners, and a Siamese insert. The first and second cylinder bores are disposed adjacent to each other. The first and second cylinder bores each comprise a first cylinder bore wall and a second cylinder bore wall, respectively, and a shared cylinder bore wall. The first cylinder bore liner is disposed on a first inner surface of the first cylinder bore wall and the second cylinder bore liner is disposed on a second inner surface of the second cylinder bore wall. The Siamese insert is disposed in a top portion of the shared cylinder bore wall.

A structural frame is provided herein. The structural frame may provide a lubrication passage that feeds a lubricant to a cylinder block. The structural frame may increase cylinder block strength while allowing a cylinder block to be constructed of less material.

An engine cooling structure includes a cylinder block including a block inner peripheral wall that defines a water jacket and a block outer peripheral wall, a spacer housed in the water jacket, and a cooler provided outside the engine body. The spacer includes: a peripheral wall surrounding the block inner peripheral wall; and a dividing wall protruding from the peripheral wall to divide the water jacket into an upper passage and lower passages below the upper passage. A coolant introduced from a coolant inlet into the upper passage passes through an inter-bore part of the block inner peripheral wall. The coolant in the lower passages is introduced into the cooler through a coolant exit.

A combustion engine housing with cylinder cooling includes at least one cylinder. The cylinder cooling channel has a distribution cross-sectional area having a cross-sectional area through which coolant can flow, in a first cross-sectional plane that is perpendicular to the cylinder axis. In a second cross-sectional plane, which is perpendicular to the cylinder axis and which is arranged in relation to the vertical direction between the first cross-sectional plane and the coolant outflow opening, has a throttle cross-sectional area, which is a cross-sectional area through which coolant can flow. The throttle cross-sectional area is smaller than the distribution cross-sectional area.

A cylinder block for use in an internal combustion engine includes a first and second cylinder bores, a first and second cylinder bore liners, and a Siamese insert. The first and second cylinder bores are disposed adjacent to each other. The first and second cylinder bores each comprise a first cylinder bore wall and a second cylinder bore wall, respectively, and a shared cylinder bore wall. The first cylinder bore liner is disposed on a first inner surface of the first cylinder bore wall and the second cylinder bore liner is disposed on a second inner surface of the second cylinder bore wall. The Siamese insert is disposed in a top portion of the shared cylinder bore wall.

An engine and a method of forming an engine are provided. The engine has a block that defines a cooling jacket extending continuously about an outer perimeter of first and second siamesed cylinders. The block defines a series of head bolt bores intersecting a deck face such that each cylinder is surrounded by four bores. The jacket has a first floor and a second floor. The second floor is offset above the first floor and extends along an intake side of the block between midpoints of the first and second cylinders, respectively. The second floor is configured to decouple a relationship between the cooling jacket and the series of bores for each cylinder and reduce fourth order bore distortion for each cylinder.

A cylinder liner that is casted in a block and defines a cylinder bore for one cylinder includes: a cylindrical liner body; a projection part including a plurality of projections on an outer peripheral surface of a part of the liner body; and a bore adjacent part inclined at a predetermined angle to an axial direction of the body and extending in the inclination direction, at a predetermined part between an upper side end and a lower side end of the body, of the outer peripheral surface of the body, which faces another cylinder bore to be adjacent when casted in the block. The outer peripheral surface of the bore adjacent part is positioned more on an inner side of the body than the outer peripheral surface above and below, and is formed such that the projections are absent on at least a part of the outer peripheral surface.