A method of operating a fan for an air-cooled internal combustion engine includes starting the air-cooled internal combustion engine, operating the fan in a first operating mode in which the fan rotates in a first direction, and operating the fan in a second operating mode in which the fan rotates in a second direction.

An air-cooled internal combustion engine including a crankshaft rotating about a crankshaft axis, a first cylinder having a first cylinder head, a second cylinder having a second cylinder head, and a blower assembly. The blower assembly includes a blower housing, a first fan, and a second fan. The first fan is positioned proximate the first cylinder and the second fan is positioned proximate the second cylinder. The first fan and the second fan are each received within the blower housing.

In an internal combustion engine that includes a cylinder block and a cylinder head, and has a cam chain chamber on a side of the cylinder block, a beam member that traverses the cam chain chamber is disposed in the cam chain chamber.

An engine includes: a cylinder block in which a cooling water passage is formed; an oil cooler accommodated in an accommodation part provided in the cooling water passage and having a plurality of cores for cooling an engine oil; a first oil pipe and a second oil pipe configured to support an oil inflow port and an oil ejection port of each of the cores; a cooling water inflow port provided in a lower portion of one end portion of the accommodation part relative to a front-and-rear direction; a cooling water outflow port provided in an upper portion of the accommodation part; and a cooling water inflow passage having an inclined portion inclined downward and connecting to the cooling water inflow port.

A cylinder liner is provided that includes a cylinder bore capable of housing a piston, a top end having an annular flange, a first cylindrical section, a second cylindrical section, and an annular ridge that separates the first cylindrical section and the second cylindrical section. When employed in an a liner bore of an engine bock, the cylinder liner provides for two channels that allow for coolant to be supplied to the cylinder liner.

A piston of an internal-combustion engine may include a piston head and a piston skirt, a cooling duct circulating in the piston head, a boss for receiving a piston pin, and a feed hopper for supplying cooling oil into the cooling duct. The feed hopper may be fastened to another component of the piston via a retaining lug by at least one of a material closure, a force closure, and a positive closure.

Methods and systems are provided for a cooling arrangement. In one example, the cooling arrangement comprises flowing coolant to only an upper portion of a cylinder head during a cold-start. The cooling arrangement comprises flowing coolant to a cylinder block, a lower portion of the cylinder-head, and the upper portion of the cylinder head outside of the cold-start.

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 marine engine comprises a powerhead having an engine block, a cylinder head and a crankcase containing a crankshaft. Operation of the marine engine causes rotation of the crankshaft. A crankcase cover encloses the crankshaft in the crankcase. A supercharger is on the crankcase cover, the supercharger being configured to provide charge air for combustion in the powerhead. A cooling passage conveys cooling fluid between the crankcase cover and the supercharger so that the cooling fluid cools both in the crankcase and in the supercharger.

A cylinder head with integrated exhaust manifold includes a cylinder head housing, an exhaust manifold, and first, second and third water jackets. The cylinder head housing has a combustion chamber formed in a bottom surface thereof and an internal receiving space. The exhaust manifold is received in the space of the cylinder head housing and is connected to exhaust ports of the cylinder head housing. The first water jacket is received in the space of the cylinder head housing and disposed adjacent to the combustion chamber. The second water jacket is received in the space of the cylinder head housing and disposed to contact a bottom of the exhaust manifold. The third water jacket is received in the space of the cylinder head housing and disposed to contact a top of the exhaust manifold.