Abstract: There is provided a cylinder head cooling apparatus of an engine capable of enhancing cooling efficiency around an auxiliary combustion chamber wall. The cylinder head cooling apparatus of an engine including a cylinder head having therein an intake port, an exhaust port, an auxiliary combustion chamber, and a cooling water jacket, in which an intake port wall, an exhaust port wall, and an auxiliary combustion chamber wall are placed in the cooling water jacket, the cooling water jacket includes a cooling water inlet and a cooling water outlet, engine cooling water flowed from the cooling water inlet into the cooling water jacket flows out from the cooling water outlet through the cooling water jacket, wherein a cooling water guide wall is provided upstream of the auxiliary combustion chamber wall in a cooling water passing path of the cooling water jacket, and the upstream cooling water guide wall is formed into a shape whose width gradually widens toward a downstream side.

Abstract: 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.

Abstract: There is provided a cylinder head cooling apparatus of an engine capable of enhancing cooling efficiency around an auxiliary combustion chamber wall. The cylinder head cooling apparatus of an engine including a cylinder head having therein an intake port, an exhaust port, an auxiliary combustion chamber, and a cooling water jacket, in which an intake port wall, an exhaust port wall, and an auxiliary combustion chamber wall are placed in the cooling water jacket, the cooling water jacket includes a cooling water inlet and a cooling water outlet, engine cooling water flowed from the cooling water inlet into the cooling water jacket flows out from the cooling water outlet through the cooling water jacket, wherein a cooling water guide wall is provided upstream of the auxiliary combustion chamber wall in a cooling water passing path of the cooling water jacket, and the upstream cooling water guide wall is formed into a shape whose width gradually widens toward a downstream side.

Abstract: 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.