The air intake system includes a first piece, an intermediate piece constituting a surge tank and joined to the first piece, and a second piece including an air intake passage upstream portion in communication with the surge tank, the second piece being joined to the intermediate piece. The first piece and the intermediate piece constitute an air intake passage downstream portion in communication with the air intake passage upstream portion. The second piece further includes a flange portion that connects the air intake passage downstream portion and an air intake port of an internal combustion engine.

An intake manifold is provided. A first inlet is structured to receive pressurized intake air from a turbocharger. A second inlet is structured to receive exhaust gas recirculation gas from an exhaust gas recirculation system. A third inlet is structured to receive fuel from a fuel line. A plurality of outlets are structured to be fluidly coupled to an engine. An intake manifold passage extends between each of the first, second, and third inlets, and the plurality of outlets. The intake manifold passage is shaped so as to cause at least two reversals in flow direction of each of the intake air, the exhaust gas recirculation gas, and the fuel through the intake manifold passage so as to improve mixing of each of the intake air, the exhaust gas recirculation gas, and the fuel.

An intake manifold is provided with a surge tank and a plurality of branch pipes branching from the surge tank, and is made up of a plurality of separate pieces. Each of the branch pipes is provided with an intake outlet for outflow of intake air to each cylinder of an engine. The intake manifold further includes a single gas inflow port, a plurality of gas outflow ports opening one in each of the branch pipes, and a gas passage extending in a branch form from the gas inflow port to each of the gas outflow ports. Each of the gas outflow ports is located away from the intake outlet of the corresponding branch pipe by a predetermined passage length.

An air intake manifold for an internal combustion engine having a top shell and a base weldment. The base weldment is formed by permanent joining of a bottom shell having a plurality of air outlets with a runner assembly having a plurality of runner components each having an air inlet and an air outlet, wherein the plurality of runner components are attached to one another via a support member to form the runner assembly.

An exhaust manifold comprises a plurality of exhaust intake conduits structured to be fluidly coupled to an engine and receive exhaust gas from a corresponding cylinder of the engine. At least one exhaust intake conduit provides a reduction in an exhaust intake conduit cross-sectional area from an inlet to an outlet. A plurality of bends are each defined by a respective one of the exhaust intake conduit outlets. An exhaust intake manifold is fluidly coupled to the exhaust intake manifold and defines an exhaust intake manifold flow axis. Each of the plurality of bends is shaped so as to define n angle of approach of exhaust gas flowing therethrough. A first angle of approach of the first bend relative to the exhaust intake manifold flow axis is smaller than a second angle of approach of an inner second bend.

An exhaust manifold comprises a plurality of exhaust intake conduits structured to be fluidly coupled to an engine and receive exhaust gas from a corresponding cylinder of the engine. At least one exhaust intake conduit provides a reduction in an exhaust intake conduit cross-sectional area from an inlet to an outlet. A plurality of bends are each defined by a respective one of the exhaust intake conduit outlets. An exhaust intake manifold is fluidly coupled to the exhaust intake manifold and defines an exhaust intake manifold flow axis. Each of the plurality of bends is shaped so as to define an angle of approach of exhaust gas flowing therethrough. A first angle of approach of the first bend relative to the exhaust intake manifold flow axis is smaller than a second angle of approach of an inner second bend.

Piston engine updraft and downdraft air intake systems, having a heat exchanger core and first and second intercooler flange structures having the same pattern of bolt apertures. The updraft air intake system has an air inlet component with an air inlet flange bolted to and having the same pattern of bolt apertures as the first intercooler flange structure, with the assembly configured to be mounted over the engine intake manifold with the air inlet component below the heat exchanger core. The downdraft air intake system has an air distribution tray with distribution channels, and an air passage closure tray that mates with the air distribution tray to form air conduits with outlet ports configured to be connected to cylinder air intake ports, and an air tray distribution flange bolted to and having the same pattern of bolt apertures as the second intercooler flange structure.

A two-wheeled vehicle includes a frame assembly having a front end and a rear end extending along a longitudinally-extending centerline, a front ground-engaging member operably coupled to the front end of the frame assembly at a front rotational axis, and a rear ground-engaging member operably coupled to the rear end of the frame assembly at a rear rotational axis. The vehicle further includes an engine supported by the frame assembly and operably coupled to the front and rear ground-engaging members, and the engine includes a throttle body assembly. Additionally, the vehicle includes an air intake assembly fluidly coupled to the engine and including an airbox and a mounting plate having a first channel and a second channel. The first and second channels are configured to align with the throttle body assembly. The mounting plate is configured to couple the airbox to the throttle body assembly.

A two-wheeled vehicle includes a frame assembly having a front end and a rear end extending along a longitudinally-extending centerline, a front ground-engaging member operably coupled to the front end of the frame assembly at a front rotational axis, and a rear ground-engaging member operably coupled to the rear end of the frame assembly at a rear rotational axis. The vehicle further includes an engine supported by the frame assembly and operably coupled to the front and rear ground-engaging members, and the engine includes a throttle body assembly. Additionally, the vehicle includes an air intake assembly fluidly coupled to the engine and including an airbox and a mounting plate having a first channel and a second channel. The first and second channels are configured to align with the throttle body assembly. The mounting plate is configured to couple the airbox to the throttle body assembly.

Internal combustion engine comprising—a first pair of cylinders which accommodate, according to a rectilinear reciprocating motion, relative first pistons operatively associated to a motor shaft rotating around a motor axis disposed in a transverse direction, perpendicular to a longitudinal running direction of an associable vehicle, —a suction system comprising a filter box which delimits a suction volume which houses at least a first front suction duct and at least a first rear suction duct, respectively disposed in an advanced and retracted position in relation to an air/suction mixture inlet direction, each suction duct channelling the air/suction mixture before entering in the respective cylinders, —wherein said first front and rear suction ducts are fixed and have respective mutually different lengths.