An engine includes a common rail attached to one side portion of a cylinder block that pivotally supports a crankshaft in a rotatable mariner, the one side portion extending along a crankshaft center, and the common rail being configured to supply a fuel to the engine. A flywheel housing that accommodates a flywheel that is rotated integrally with the crankshaft is disposed in one side portion out of opposite side portions of the cylinder block intersecting the one side portion. One end portion of the common rail is disposed above the flywheel housing.

An engine including a common rail attached to one side portion of a cylinder block that pivotally supports a crankshaft in a rotatable manner, the one side portion extending along a crankshaft center, and the common rail being configured to supply a fuel to the engine. A flywheel housing that accommodates a flywheel that is rotated integrally with the crankshaft is disposed in one side portion out of opposite side portions of the cylinder block intersecting the one side portion. One end portion of the common rail is disposed above the flywheel housing.

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 heat exchanger includes a heat exchanger body arranged along an axis and having an external surface in contact with a surrounding first fluid. The body defines a first fluid passage centered on and extending along the axis. The body also defines a second fluid passage extending parallel with respect to the axis and spaced away from the axis by a second passage distance, and a third fluid passage extending parallel with respect to the axis and spaced away from the axis by a third passage distance. The first, second, and third passages are parallel to one another, while the third passage distance is greater than the second passage distance. Each of the first and third passages is configured to accept a flow of a second fluid and the second fluid passage is configured to hold a volume of air to thermally insulate the first passage from the third passage.

An oil cooling structure of an engine is provided that is capable of enhancing cooling performance of oil while preventing an increase in number of components or an increase in required space from being involved as much as possible. In an oil cooling structure of an engine in which a transmission case is attached to one end wall of an engine body, and a transmission mechanism for an accessory drive is provided in the transmission case, the transmission case is formed into a potlid-shaped body having a plurality of rib walls along a front-rear direction, and is attached to an engine front wall with an engine cooling fan, and case inner chamber portions partitioned by the rib walls in the transmission case are configured as a transporting passage of oil circulated by an oil pump.

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.

The cooling apparatus of the internal combustion engine according to the invention executes an incompletely-warmed state control for supplying the cooling water to the cylinder block water passage from the cylinder head water passage without flowing the cooling water through the radiator and supplying the cooling water to the cylinder head water passage from the cylinder block water passage when the temperature of the cooling water is lower than the engine completely-warmed water temperature at which the engine is estimated to be warmed completely.

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.

A cylinder head assembly for an engine assembly is provided herein. The cylinder head assembly may include a head framework, an exhaust liner include a thermal barrier material, an intake liner, and a polymeric housing disposed around at least a portion of the metal head framework and the exhaust liner. The cylinder head assembly may further include a plurality of channels for heating and/or cooling the cylinder head assembly, which can be defined in one or more of: the metal head framework, the exhaust liner, and the polymeric housing. Methods of making the cylinder head assembly are also provided herein.

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.