An internal combustion engine system includes at least one combustor, a compressor arranged to compress air, an air guide arranged to guide compressed air from the compressor to at least one of the at least one combustor, an expander arranged to expand exhaust gases from at least one of the at least one combustor and to extract energy from the expanded exhaust gases, and an exhaust guide arranged to guide exhaust gases from at least one of the at least one combustor to the expander, wherein the exhaust guide is at least partly integrated with the air guide.

A breather device for an engine which prevents a blow-by gas outlet passage from being blocked due to freezing, is provided, which includes a valve holder in a cylinder head cover and a breather valve supported by the holder. The holder includes a holder body having a valve port of the breather valve, a metal outlet passage pipe having a blow-by gas outlet passage formed inside, the blow-by gas outlet passage communicating with the valve port and being located below the valve port, and a heater that heats the outlet passage pipe. An outer peripheral surface of the outlet passage pipe is wrapped with the holder body formed of a material having lower thermal conductivity than that of the outlet passage pipe. The holder body has a heater insertion port, and the heater is inserted from the heater insertion port toward a heat input wall of the outlet passage pipe.

A side-by-side vehicle includes a vehicle body frame including a cabin frame part surrounding a riding space; a driving power unit which is supported by the vehicle body frame and generates driving power for allowing the vehicle to travel; a continuously variable transmission (CVT) to which the driving power is transmitted from the driving power unit, in a state in which the CVT is supported by the vehicle body frame; an air-intake unit including in an inside thereof, an air-intake passage through which intake-air flows to the CVT, and an air inlet through which the intake-air is introduced into the air-intake passage; and a cargo carrier having a depressed loading space in a state in which the cargo carrier is supported by the vehicle body frame, wherein the air inlet of the air-intake unit is directed downward and faces a surface of the cargo carrier.

The cylinder head includes an intake port communicating with a cylinder of a cylinder block, a cylinder head main body having an exhaust port communicating with the cylinder, and a rocker housing integrally formed on the cylinder head main body and an inner side of which is defined as a valve-system accommodating space. The rocker housing includes a lateral wall having a lateral wall main body and a base end portion which extends along a lower end of the lateral wall main body, connects the lateral wall main body to the cylinder head main body, and has a thickness thicker than that of the lateral wall body. A flow path which extends in an extending direction of the base end portion and through which a fluid flow is formed in the base end portion.

A vehicle includes an engine, an engine cover, and a cross component. The engine cover has a through-hole through which the cross component passes. The cross component is a flexible hose or a flexible pipe in which a body part extending in a cross direction is integrated with a diameter enlarged part having a diameter larger than the body part. The outer peripheral part of the diameter enlarged part makes close contact with the inner peripheral surface of the through-hole of the engine cover.

An intake manifold includes: multiple branch pipes having downstream ends fastened to a front or rear surface of a cylinder head; a main pipe connected to upstream ends of the branch pipes; and a cover including a cover main body attached to an upper surface of a portion of at least one of the branch pipes to define a blow-by gas passage, and a protrusion protruding upward from the cover main body, the portion of the at least one of the branch pipes being adjacent to the cylinder head, wherein the protrusion is spaced apart from the cylinder head in a fore and aft direction such that a fuel line positioned above the downstream ends of the branch pipes is interposed between the protrusion and the cylinder head in the fore and aft direction, the protrusion being positioned to overlap a part of the fuel line as seen from front.

An intake system for an internal combustion engine has at least one inlet channel through which air can flow and by which the air flowing through the inlet channel is to be conducted into at least one combustion chamber of the internal combustion engine. The inlet channel is, on the bottom side thereof, of flat form at least in one length region, wherein the flat bottom side extends as far as a tumble edge by which a tumbling flow of the air flowing into the combustion chamber can be effected.

A side-by-side vehicle includes a vehicle body frame including a cabin frame part surrounding a riding space; a driving power unit which is supported by the vehicle body frame and generates driving power for allowing the vehicle to travel; a continuously variable transmission (CVT) to which the driving power is transmitted from the driving power unit, in a state in which the CVT is supported by the vehicle body frame; an air-intake unit including in an inside thereof, an air-intake passage through which intake-air flows to the CVT, and an air inlet through which the intake-air is introduced into the air-intake passage; and a cargo carrier having a depressed loading space in a state in which the cargo carrier is supported by the vehicle body frame, wherein the air inlet of the air-intake unit is directed downward and faces a surface of the cargo carrier.

A side-by-side vehicle comprises a vehicle body frame including a cabin frame part surrounding a riding space in which seats for a driver and a passenger are provided; an engine which is mounted on the vehicle body frame and generates driving power for allowing the side-by-side vehicle to travel; an air-intake unit including in an inside thereof, an air-intake passage through which intake-air flows to the engine, and an air inlet through which the intake-air is introduced into the air-intake passage; and a cargo carrier having a loading space with a depressed shape in a state in which the cargo carrier is supported by the vehicle body frame, and the air-intake unit is disposed so that the air inlet is directed downward and faces a surface of the cargo carrier.

An intake port may include a short port and a long port. The short port may include a main extension portion extending from an intake air inlet; a main inclined portion inclined at a predetermined angle from the main extension portion toward a center of a cylinder; a main vertical portion which bends downward toward the cylinder from the main inclined portion; and a main intake air outlet formed at an end portion of the main vertical portion. The long port may include an auxiliary extension portion extending from the main extension portion; an auxiliary vertical portion bending downward toward the cylinder from the auxiliary extension portion; and a partition wall portion between the auxiliary extension portion and the auxiliary vertical portion, which allows the intake air to flow in a direction opposite to a direction in which the intake air introduced into the cylinder through the short port flows.