A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

A utility vehicle includes: an air-cooled engine; a cooling fan disposed on one side of the engine with respect to a vehicle widthwise direction and configured to supply a cooling air towards a cylinder unit of the engine; an exhaust pipe disposed on the other side of the engine with respect to the vehicle widthwise direction and connected with an exhaust port of the cylinder unit; an oxygen sensor fitted to the exhaust pipe; and a shield configured to prevent muddy water, which is swirled by the cooling fan, from depending on the exhaust pipe.

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 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.

Methods and systems are provided for cooling an engine by operating an electrically driven intake air compressor. In one example, in response to a determination, based on a measured or inferred engine temperature, that the engine temperature is greater than a threshold temperature, employing the vehicle's electrically driven intake air compressor to route air through a charge air cooler and engine cylinders, while engine spins unfueled. In this way the engine temperature may be reduced even under conditions not normally amenable to engine cooling, such as at idle-stops or when an engine coolant system is degraded.

An engine blower is achieved which can obtain a large blowing volume and a high cooling efficiency of the cylinder and the muffler. A suction opening is formed in the second case partitioning the volute chamber and the muffler chamber at the front of the partition plate and at the rear of the muffler cover. The volute chamber has a shape that the width perpendicular to the front-rear direction is locally narrowed behind the suction opening, and a first curved portion is provided immediately after the suction opening, and a first curved portion is provided in the second case. Immediately before the first curved portion, the air pressure locally drops due to the air supply flow whose flow velocity is increased. The air pressure becomes a negative pressure state when viewed from the muffler chamber. Air flows from the muffler chamber side to the volute chamber side via the suction opening.

Methods and systems are provided for reducing temperature of an engine or single cylinder(s) of the engine at start/stop events where the engine is stopped from combusting air and fuel, and in response to an overheating engine condition. In one example, a method comprises activating an electric air compressor to direct cooling air flow through a first single cylinder of the engine, to reduce a temperature of the first single cylinder to a desired temperature prior to a request to restart the engine. In this way, a single cylinder indicated to be overheating may be effectively cooled, without employing methodology that would otherwise cool the engine as a whole, which may thus prevent engine degradation and which may conserve power of an onboard energy storage device.

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 motor engine having an oxygen sensor is provided, including: a cylinder head, including a main body and a protruding tube protruding outwardly from the main body, the main body including a first end portion, a second end, and a combustion chamber, the protruding tube having a protrusive receptacle protruding outwardly therefrom, the main body defining an axial direction; an exhaust passage, communicated with the combustion chamber and the protruding tube; an oxygen sensor, inserted into the protrusive receptacle, including a sensing portion which is inserted into the exhaust passage; wherein as viewed in a lateral direction of the cylinder head, two surfaces of the main body along the axial direction disposed on two opposite sides defines two boundary lines, the oxygen sensor and the main body are in an overlapping arrangement and does not protrude out of the two boundary lines.

An engine is configured so that a muffler is affixed to the exhaust opening of the cylinder, and the air-cooled cylinder is cooled by a cooling fan. The engine is provided with a muffler cover for covering the muffler, and exhaust gas is discharged inside the muffler cover along the wall surface of the muffler. A second cooling air is combined with the exhaust gas flow from the upstream side thereof to be parallel thereto, and a first cooling air having been caused to flow under the muffler is caused to perpendicularly impinge against the exhaust gas flow on the downstream side thereof. Thus, the cooling airs are combined inside the muffler cover with the exhaust gas flow, and as a result the temperature of the exhaust gas is sufficiently reduced at the time when the exhaust gas is discharged from the opening of the muffler cover to the outside.