An air intake system includes an air cleaner for housing an air filter element therein above an off road vehicle engine, and a surge tank, which buffers the filtered air, at a location beside the engine. A descending tube from the air cleaner connects into a top cover of the surge tank, and an outlet tube of the air intake system extends horizontally from the top cover of the surge tank for connection into the throttle of the engine. A vapor recovery pipe connect the crankcase of the engine, lower than the outlet tube, back up to the air cleaner upstream of the filter element. The surge tank includes a tank bottom casing removably connected to a tank upper cover, with the descending tube and the outlet tube connecting into the tank upper cover.

A turbocharger and method of controlling the same includes a turbine housing comprising an inlet and an outlet, turbine wheel coupled to a shaft. The turbine housing comprising a first scroll and a second scroll for fluidically coupling the inlet and the turbine wheel. The first scroll has a first end adjacent the inlet and a second end adjacent the turbine wheel. The second scroll has a third end adjacent the inlet and a fourth end adjacent the turbine wheel. An exhaust gas diverter valve is coupled to the turbine housing restricting flow into the first scroll or the second scroll.

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.

Methods and systems are provided for modified intake runners including ribs in the direction of airflow. In one example, a system may include an intake manifold adapted to couple to an intake port via an intake runner. Internal to the intake runner, a plurality of negative ribs may be arranged along a direction of air flow on a façade of an inner portion.

An engine includes a crankshaft. A driveshaft is connected to the crankshaft, and extends in an up-and-down direction of an outboard motor. A propeller shaft is connected to the driveshaft, and extends in a back-and-forth direction of the outboard motor. An intake pipe is connected to the engine. The intake pipe includes a first pipe portion and a second pipe portion that are provided separately from each other. A seal member is disposed between the first and second pipe portions, and couples the first and second pipe portions therethrough.

This air distributor (1) has an exterior casing defining an interior volume, an air inlet (4) opening into this interior volume, several air outlets (4) intended to convey air from the interior volume towards the cylinders of an engine, and a heat exchanger (8) arranged in the interior volume. The heat exchanger (8) comprises a stack of plates (10) of plastic material where adjacent plates (10) are arranged so as to define a set of intermediate spaces comprising closed intermediate spaces (12) in fluid communication to enable circulation of fluid through the stack of plates (10), and open intermediate spaces (14) configured to enable a passage of air through the stack of plates (10) from the air inlet (4) to the air outlets (6).

An intake manifold includes a passage wall portion having a first member passage wall portion provided at a first member, a second member passage wall portion provided at a second member, and an inner joint portion including a division point at which an inner joint portion is divided from an outer peripheral joint portion, the inner joint portion at which the first member passage wall portion and the second member passage wall portion are joined with each other. At least a part of the inner joint portion except for the division point is arranged at a height position closer to a middle part of a gas passage than the division point in a first direction in which the first member and the second member are opposed with each other.

A system for reducing noise associated with a compressor of an engine system comprises an intake manifold and a resonator comprising an outlet. The resonator is coupled to, and is positioned adjacent to, the intake manifold. An outlet pipe is in fluid communication with the outlet and the compressor, and a length of the outlet pipe extends from the outlet to the compressor. Positioning the resonator adjacent to the intake manifold reduces the length of the outlet pipe so as to reduce noise associated with air flowing through the outlet pipe.

An air intake system includes an air cleaner for housing an air filter element therein above an off road vehicle engine, and a surge tank, which buffers the filtered air, at a location beside the engine. A descending tube from the air cleaner connects into a top cover of the surge tank, and an outlet tube of the air intake system extends horizontally from the top cover of the surge tank for connection into the throttle of the engine. A vapor recovery pipe connect the crankcase of the engine, lower than the outlet tube, back up to the air cleaner upstream of the filter element. The surge tank includes a tank bottom casing removably connected to a tank upper cover, with the descending tube and the outlet tube connecting into the tank upper cover.

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.