A system for controlling the temperature of an engine, which includes at least one cylinder. The system includes a turbocharger and at least one air-nozzle. The turbocharger includes exhaust-gas-inlet-port, an exhaust-gas-outlet-port, an air-inlet-port, a compressed-air-outlet-port, a turbine and a compressor. The exhaust-gas-inlet-port is coupled with the exhaust-gas-outlet of the engine. Exhaust gas from the engine rotates the turbine, which rotates the compressor. The compressor draws air from the air inlet port, compresses the air thereby increasing the pressure thereof, and provides the compressed air to the compressed-air-outlet-port. An inlet of the air-nozzle or nozzles is coupled with the compressed-air-outlet-port. The air-nozzle or nozzles are directed toward a respective one of the at least one cylinder, and directs a flow of air toward the respective one of the at least one cylinder.

A front fender is provided in front of an air-cooled engine which is a drive source of a motorcycle. An air introduction hole which opens frontward is formed at a front part of a cylinder head of the air-cooled engine. A space around a plug attachment portion for a spark plug and a space in front of the cylinder head communicate with each other through the air introduction hole. A guide portion for guiding incoming wind toward the air introduction hole is formed at a rear part of the front fender.

A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.

A heat management system for air-cooled engines suitable to power yard care equipment or vehicles. The system may generally comprise an engine, a blower configured to blow ambient cooling air across the engine, and an exhaust system comprising an exhaust header and a muffler. The exhaust header has an inlet end which receives heated exhaust gas from the engine and an outlet end fluidly coupled to the muffler. An air control baffle is configured to redirect a portion of the cooling air from the blower towards the exhaust header and the muffler to enhance cooling the exhaust system. The system may further include an outermost protective shield exposed to equipment operators and an inner heat barrier or shield located between the muffler and protective shield. The system is designed to ameliorate both radiative and convective sources of heat transfer to maintain the protective shield at temperatures below established industry standards.

A heat management system for air-cooled engines suitable to power yard care equipment or vehicles. The system may generally comprise an engine, a blower configured to blow ambient cooling air across the engine, and an exhaust system comprising an exhaust header and a muffler. The exhaust header has an inlet end which receives heated exhaust gas from the engine and an outlet end fluidly coupled to the muffler. An air control baffle is configured to redirect a portion of the cooling air from the blower towards the exhaust header and the muffler to enhance cooling the exhaust system. The system may further include an outermost protective shield exposed to equipment operators and an inner heat barrier or shield located between the muffler and protective shield. The system is designed to ameliorate both radiative and convective sources of heat transfer to maintain the protective shield at temperatures below established industry standards.

An engine system which combines an internal combustion engine with a unique air-cooling system. The air-cooling system includes a cooling cylinder(s) which is disposed in the engine block. Input air is expanded through the cooling cylinder from the intake manifold directly to the exhaust manifold. No high compression or combustion takes place in the cooling cylinder. Heat from the cooling cylinder is transferred to the input air, and the heated air is then exhausted to the internal combustion engine exhaust stream where it is used to help power a turbocharger.

One embodiment of the invention relates to an internal combustion engine including an engine block having a first cylinder and a second cylinder, a crankshaft configured to rotate about a crankshaft axis, a flywheel coupled to the crankshaft, a throttle body, an air filter assembly, a first electric fan coupled to a first duct, and a second electric fan coupled to a second duct. The first duct is configured to direct cooling air directly over the first cylinder. The second duct is configured to direct cooling air directly over the second cylinder. The first cylinder is at least partially within the first duct. The second cylinder is at least partially within the second duct.

A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.

A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.

An engine according to the present disclosure includes: a crankcase which supports a crankshaft of the engine; a cylinder which is removably connected to the crankcase and protrudes from the crankcase in a cylinder axis direction; a cooling fan which is attached to the crankshaft and rotates in conjunction with the crankshaft; and a cover which guides cooling air generated by the cooling fan to an outer surface of the cylinder. The cover includes an opening part which allows a portion of the cooling air to flow toward an outer surface of the crankcase.