An engine includes a crankcase with cylinders and fins on outer circumferences of the cylinders. A crank shaft penetrates the crankcase. A cooling fan is provided on an outer side of the crankcase and arranged coaxially with the crank shaft. A first cover covers an outer side of the cylinders and the crankcase, and the cooling fan. A second cover capable of being detached from/attached to the first cover. The first cover includes a first opening facing the cooling fan, and second openings facing the fins. The second cover includes an air inlet facing the first opening, and attached to the first cover to cover the first opening and the second openings.

A coolant outlet system for a cylinder head associated with an engine includes a core hole communicating with an upper surface thereof, wherein the core hole is in fluid communication with a coolant jacket of the cylinder head. The coolant outlet system includes an outlet tube having a first end and a second end, wherein the first end of the outlet tube is coupled to the core hole. The coolant outlet system also includes a jumper elbow coupled to the second end of the outlet tube, wherein the outlet tube and the jumper elbow provide fluid communication between the coolant jacket and an engine crankcase to introduce coolant discharged from the core hole into the engine crankcase.

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.

A rotary internal combustion engine includes a rotor housing having a peripheral wall circumscribing a rotor cavity and a rotor disposed within the rotor cavity. A side housing is secured to the rotor housing and a plate defines a seal running surface for the rotor. The plate is disposed between a portion of the side housing and the rotor housing and at least one shim is disposed between the plate and the side housing for spacing the plate apart from contact with the side housing.

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.

A rotary internal combustion engine includes a rotor housing having a peripheral wall circumscribing a rotor cavity and a rotor disposed within the rotor cavity. A side housing is secured to the rotor housing and a plate defines a seal running surface for the rotor. The plate is disposed between a portion of the side housing and the rotor housing and at least one shim is disposed between the plate and the side housing for spacing the plate apart from contact with the side housing.

Engine assemblies and methods of heating and/or cooling the engine assemblies are provided. The engine assembly has a metal liner defining a cylindrical region for receiving a piston, a polymeric composite housing disposed around at least a portion of the exterior surface of the metal liner, and a metal cylinder head. The polymeric composite housing comprises a polymer and a plurality of reinforcing fibers and at least one of: a plurality of microchannels for receiving a heat transfer fluid for heating and/or cooling the engine assembly; and at least one wire for heating the engine assembly.

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 engine system having a coolant control valve may include a cylinder block configured with cylinders, a cylinder head sitting on top of the cylinder block and comprising exhaust ports and intake ports configured to lead to the cylinders, an Exhaust Gas Recirculation (EGR) cooler, a heater core, an oil cooler, or a radiator through which coolant circulates, and a coolant control valve configured to control a coolant supplied to the cylinder block, a coolant discharged from the cylinder block through the cylinder head, and a coolant supplied to the EGR cooler, the heater core, the oil cooler, or the radiator.

An air-cooled internal combustion engine including a crankshaft, a cylinder, a blower assembly including a blower housing and a fan, and a static cover. The static cover includes a main body that is aligned with the crankshaft, an arm that extends from the main body and is aligned with the cylinder, and a plurality of air intake openings. A first subset of the air intake openings is formed through the main body and a second subset of the air intake openings is formed through the arm, and the static cover is configured to prevent user access to a moving component of the engine. The fan is configured to move air into the blower housing through the air intake openings.