An engine cooler capable of suppressing a piston slap sound is provided. The engine cooler includes a cylinder block including a cylinder barrel and a water jacket, and a spacer stored in the water jacket, the water jacket surrounds the cylinder barrel, and the spacer encloses the cylinder barrel. Given that a width direction of the cylinder block is a lateral direction, a pressed member is pressed between the cylinder barrel and the spacer on lateral sides of the cylinder barrel, and a lower end of the pressed member is disposed above a lower end of each of right and left skirts of a piston located at a top dead center.

A bridge member is installed in an opening of a water jacket, and a probe of a friction stir welding tool, which rotates about an axis parallel to a cylinder axis, is pressed against a central part of an upper surface of the bridge member. The probe is kept pressed against the central part of the upper surface for a predetermined time to cause side surfaces of the bridge member to expand and come into contact with both a cylinder wall and an outer wall. The probe is moved from the central part of the upper surface to the outer wall, or the cylinder wall, while the probe is kept pressed against the upper surface, thereby friction-stir welding the outer wall, or the cylinder wall, with the bridge member to each other, and after that, the probe is removed off the top deck.

A slide for the high pressure die casting of at least one closed deck engine block having at least one cylinder is disclosed. The slide includes a tool steel portion with reliefs for forming a water jacket surrounding each cylinder. At least one expendable core is located in each relief, the expendable core having an inner surface and an outer surface with an aperture extending therethrough. The outer surface and inner surface of the expendable core is coextensive with an inner surface and outer surface of the tool steel portion. A method for high pressure die casting a closed deck engine block using the disclosed slide and expendable cores is also disclosed. The expendable cores are separable from the reliefs in the slide, and form bridges or supports across a water jacket to add stiffness and rigidity to the cast engine cylinders.

An internal combustion engine body includes a cylinder block including a plurality of cylinders, a first water jacket, and a second water jacket, and a cylinder head including an in-head water jacket. The in-head water jacket includes an intake-side flow passage. The cylinder block and the cylinder head are provided such that a flow rate of coolant that directly flows into the intake-side flow passage after flowing into the first water jacket is higher than a flow rate of coolant directly flows into any region other than the intake-side flow passage after flowing into the first water jacket.

There is provided a vertical multicylinder straight engine in which the temperature distribution of a plurality of cylinder barrels is made close to an even state. A cylinder jacket includes: a jacket inlet; a separated channel; a plurality of separated outlets; and heat dissipater channels for dissipating heat of the respective cylinder barrels to engine cooling water introduced through the separated outlets. The plurality of separated outlets include: a front-side separated outlet to a front-end barrel; a rear-side separated outlet to a rear-end barrel; and middle separated outlets to middle barrels between the front-end barrel and the rear-end barrel, and the jacket inlet is disposed so as to be contained within an entire middle barrel side area that is lateral to the middle barrels and has a front-rear length as long as a length from a front-most end to a rear-most end of the middle barrels.

Aspects of the present disclosure are directed to a cylinder housing of an internal combustion engine. In one embodiment of the present disclosure, the cylinder housing includes at least two adjacently arranged cylinders, each of which includes a wet cylinder liner, a support structure, and a coolant jacket arranged between the support structure and the cylinder liner. The cylinder housing further including at least one screw receptacle for a cylinder head screw, and is positioned between at least two adjacently arranged cylinders in a region of at least one engine transverse plane.

An internal combustion engine includes an anisotropic thermal conductivity member (37, 51) provided on a wall surface defining a cylinder or a wall surface of a cooling water passage on a side of the cylinder, a thermal conductivity of the anisotropic thermal conductivity member in an axial direction of the cylinder being higher than a thermal conductivity of the anisotropic thermal conductivity member in a radial direction of the cylinder, and a thermally insulating member (38. 52) provided on an outer surface of the anisotropic thermal conductivity member with respect to the radial direction of the cylinder.

A cooling structure of a water-cooled engine includes: a plurality of cylinders 2 arranged in a cylinder block 1; and a water jacket W formed around the plurality of cylinders 2. The water jacket W includes a pair of main flow paths 7, 8 formed in a state of extending in a cylinder arrangement direction outside the cylinders, and inter-bore flow paths 9, 10 formed between adjacent cylinders 2 in a state of connecting the pair of main flow paths 7, 8. Guide walls 11h, 13h, capable of guiding the cooling water flowing in the main flow paths 7, 8 to the inter-bore flow paths 9, 10, are formed in the cylinder block 1.

A slide for the high pressure die casting of at least one closed deck engine block having at least one cylinder is disclosed. The slide includes a tool steel portion with reliefs for forming a water jacket surrounding each cylinder. At least one expendable salt core is located in each relief, the salt core having an inner surface and an outer surface with an aperture extending therethrough. The outer surface and inner surface of the salt core is coextensive with an inner surface and outer surface of the tool steel portion. A method for high pressure die casting a closed deck engine block using the disclosed slide and expendable salt cores is also disclosed. The expendable salt cores are separable from the reliefs in the slide, and form bridges or supports across a water jacket to add stiffness and rigidity to the cast engine cylinders.

An internal combustion engine body includes a cylinder block including a plurality of cylinders, a first water jacket, and a second water jacket, and a cylinder head including an in-head water jacket. The in-head water jacket includes an intake-side flow passage. The cylinder block and the cylinder head are provided such that a flow rate of coolant that directly flows into the intake-side flow passage after flowing into the first water jacket is higher than a flow rate of coolant directly flows into any region other than the intake-side flow passage after flowing into the first water jacket.