A pre-cleaner for an internal combustion engine is arranged in an intake passage of the internal combustion engine at an upstream side of a filter of an air cleaner. The pre-cleaner includes a casing that includes a cylindrical side wall and swirl generation vanes that swirl intake air about an axis of the casing. The side wall has a portion located next to an upstream side of the swirl generation vanes that is formed from an air-permeable fibrous molded body.

An inlet duct for an internal combustion engine includes a duct member made of a compression molded fiber material. The duct member includes a main body and end portions provided on opposite sides in an axial direction of the main body. The main body includes at least one high-compression portion and at least one low-compression portion, which is made through compression molding at a compression ratio lower than that of the at least one high-compression portion. The at least one low-compression portion extends throughout a length in the axial direction of the main body.

A plurality of parts that constitute an intake passage connected with an intake port of an engine include a constriction part that has a protrusion formed to protrude on an inner circumferential surface side of the intake passage. The constriction part includes cylindrical connections disposed on both sides of a constriction path in which the protrusion is formed. The constriction path has an outer circumferential surface recessed inwardly in a radial direction so as to follow a shape of the protrusion. A portion recessed most of the recessed outer circumferential surface is disposed inside inner circumferential surfaces of the connections in the radial direction. The constriction path has a uniform wall thickness. The constriction part is connected upstream of the throttle body.

An intake manifold 10 includes: a surge tank 11 that is connected on an upstream side thereof to a throttle valve 13; multiple branch pipes 12 that are arranged side by side in a longitudinal direction of the surge tank 11 and respectively connected to cylinders; and a PCV chamber 15 that is provided upstream of a central part in the longitudinal direction of the surge tank 11. The intake manifold includes: a blowby gas introduction port 16g that is designed to introduce blowby gas into the PCV chamber 15; and a blowby gas exhaust port 16f that is designed to discharge the blowby gas from the PCV chamber 15 into the surge tank 11, and the blowby gas exhaust port 16f is located at a position higher than the blowby gas introduction port 16g.

An inlet duct for an internal combustion engine includes a tubular body portion having an air-permeable side wall and a tubular suction portion that is arranged on an upstream side of the body portion in an intake airflow direction and has an inner peripheral surface that expands radially outward toward the upstream side. The body portion and the suction portion are formed integrally by a compression-molded fiber molding.

An air intake structure for a saddled vehicle including a downsized air cleaner box and a sufficient intake path is provided. An air intake structure for a saddled vehicle applied to a saddled vehicle including an engine suspended from a vehicle body frame and an air cleaner box disposed behind the engine includes: a side cover mounted on a sidewall on an outer side in the vehicle width direction of the air cleaner box; and a side cover opening formed at the side cover toward the vehicle rear side. Outside air to be taken into the air cleaner box is taken from the side cover opening. The sidewall is provided with an intake opening, and the intake opening is covered with the side cover. The side cover includes a body that covers the sidewall, and a canopy member provided at the surface of the body. The side cover opening is formed of the outer edge of the canopy member.

The present disclosure relates to a device for attaching a control unit, preferentially an electronic engine control unit, to a component of an internal combustion engine. The device includes a first connecting component which is designed in order to be attached to the component of the internal combustion engine the first connecting component comprising a first fluid duct. The device further includes a second connecting component, which, via at least one damping element, is attached, spaced from the first fluid duct, to the first connecting component and is designed for mounting the control unit.

An apparatus and a method are provided for an air intake assembly configured for use with Pro Stock vehicles comprising fuel injection equipped engines. The air intake assembly comprises an air inlet that includes a distal opening disposed in a forward direction at a front of the vehicle and configured to direct incident air into the air intake assembly. An air duct is joined with the air inlet by way of a first coupler configured to maintain an airtight seal between the air inlet and the air duct. A throttle body adapter is joined with the air duct by way of a second coupler configured to maintain an airtight seal therebetween. The throttle body adapter is configured to establish an airtight coupling between the air intake assembly and a throttle body of the engine, such that the incident air is directed into the throttle body.

An intake duct for an internal combustion engine includes a tubular side wall. The side wall includes a first molded body and a second molded body that are separate from each other in a circumferential direction of the side wall. The first molded body includes first and second joints. The second molded body includes first and second joints. The first and second joints of the first molded body and the first and second joints of the second molded body are joined to each other. The first molded body includes a rib protruding toward the second molded body and extending in an axial direction of the side wall. The rib is located inward from the first and second joints of the first molded body. The second molded body includes an accommodation recess that accommodates the rib. The accommodation recess is located outward from the rib.

An intake manifold 10 includes: a surge tank 11 that is connected on an upstream side thereof to a throttle valve 13; multiple branch pipes 12 that are arranged side by side in a longitudinal direction of the surge tank 11 and respectively connected to cylinders; and a PCV chamber 15 that is provided upstream of a central part in the longitudinal direction of the surge tank 11. The intake manifold includes: a blowby gas introduction port 16g that is designed to introduce blowby gas into the PCV chamber 15; and a blowby gas exhaust port 16f that is designed to discharge the blowby gas from the PCV chamber 15 into the surge tank 11, and the blowby gas exhaust port 16f is located at a position higher than the blowby gas introduction port 16g.