Provided is a silencer including: an expansion chamber having a cuboid shape; a first pipe for being coupled to a noise source, the first pipe being coupled to an approximate center of a first surface of the expansion chamber; and a second pipe coupled to an approximate center of a second surface of the expansion chamber adjacent to the first surface. The expansion chamber has an internal space and a partition in the internal space, the partition is disposed upright on a third surface of the expansion chamber opposed to the second surface of the expansion chamber to extend from the third surface toward the second surface, and the second pipe has a central axis substantially included in the partition.

A supercharger intercooler includes three sequential Anti-Reversion Plenums (ARPs) separated by heat exchangers, in right and left air paths between the supercharger and intake ports. The intercooler resides above and beside the supercharger and has paths for each bank of a V8 engine. An air flow from the supercharger is up and into a first ARP, is split into right and left flows into right and left first heat exchangers, passes into second ARPs and turns down, flows though right and left second heat exchangers into third ARPs and then into the engine. Reversion pulses from the engine are reduced by each ARP, increasing air flow into the engine, and reducing pulsations in the air flow, thereby increasing power, improving fuel economy, throttle response, driveability, and reducing emissions.

An intake duct structure (22) of an engine intake system for an internal combustion engine of a vehicle includes a passage portion (28) internally defining an air passage having an air inlet (22A) located in an upstream end part of the passage portion and an air outlet (22B) located in a downstream end part of the passage portion, and extending above a structural member (40, 11B) of a vehicle body, and a resonator portion (29) depending from the downstream end part of the passage portion and internally defining a resonator chamber (35). The passage portion is provided with a bottom surface (28G) configured to rest on an upper surface of the structural member, and the resonator portion is provided with a vertical surface (29C) opposing a vertical surface of the structural member.

A silencer for reducing gas noise in a combustion engine intake system has a tubular casing with a first casing part and a second casing part connected to each other by a weld seam to form an outer casing wall, wherein the weld seam is a part of the outer casing wall. A third part for compensating gas noise is positioned inside the tubular casing. The third part is arranged in the tubular casing such that an annular cavity is formed by the third part and the outer casing wall. A weld flash protrudes from an inner surface of the outer casing wall into the annular cavity and is contained therein. The silencer is produced in a single welding process in which the first and second casing parts are connected to each other to form the outer casing wall and the third part is connected to the tubular casing.

Various methods and systems are provided for reducing cylinder-to-cylinder variation in exhaust gas recirculation. In one embodiment, a system comprises a first cylinder group of an engine having a first number of cylinders, a second cylinder group of the engine having a second number of cylinders that is not an integer multiple of the first number of cylinders, and an exhaust system coupled to the first cylinder group and the second cylinder group. In at least one mode of operation, the exhaust system has exhaust ports of the first cylinder group fluidly coupled to an intake of the engine and exhaust ports of the second cylinder group fluidly decoupled from the intake.

An air cleaner for an internal combustion engine is arranged to reduce intake noise. The air cleaner includes an air cleaner element for cleaning an intake air, and an elastic member for reducing intake noise by utilizing an inside space of the air cleaner. An inside space of the elastic member is in communication with the inside space of the air cleaner through a communication passage. Preferably, a surrounding space formed between the elastic member and a case portion for receiving the elastic member is opened to the outside.

An engine intake air duct 1 has an intake portion 10 that extends along a first center line A, and a main duct portion 20 that extends along a second center line B. The main duct portion 20 has a merging portion 50, a discharge opening 21, and an extending portion 40 that extends from the merging portion 50 towards an opposite end to the discharge opening 20. A reflecting wall 41 is provided at an end face of the extending portion 40. The intake portion 10 merges with the main duct portion 20 in such a way that the first center line A is directed towards a downstream end of the main duct portion 20.

A cowling for an outboard motor has port and starboard intake ports that direct flow of intake air into the cowling and extend downwardly along the aftward side of the cowling and face laterally outwardly. A duct system receives and conveys intake air intake ports to an intake conduit for the outboard motor. The duct system includes port and starboard intake troughs that extend alongside the intake ports and redirect the intake air from a generally lateral flow into the intake ports to a generally vertically downward flow and then to a generally forward flow towards the intake conduit. Port and starboard baffles that extend alongside the intake ports and direct flow of water into port and starboard channels located alongside the baffles, respectively. The channels drain the water by gravity depending on tilt and trim orientation of the outboard motor.

Provided is a silencer including: an expansion chamber having a cuboid shape; a first pipe for being coupled to a noise source, the first pipe being coupled to an approximate center of a first surface of the expansion chamber; and a second pipe coupled to an approximate center of a second surface of the expansion chamber adjacent to the first surface. The expansion chamber has an internal space and a partition in the internal space, the partition is disposed upright on a third surface of the expansion chamber opposed to the second surface of the expansion chamber to extend from the third surface toward the second surface, and the second pipe has a central axis substantially included in the partition.

An intake duct structure (22) of an engine intake system for an internal combustion engine of a vehicle includes a passage portion (28) internally defining an air passage having an air inlet (22A) located in an upstream end part of the passage portion and an air outlet (22B) located in a downstream end part of the passage portion, and extending above a structural member (40, 11B) of a vehicle body, and a resonator portion (29) depending from the downstream end part of the passage portion and internally defining a resonator chamber (35). The passage portion is provided with a bottom surface (28G) configured to rest on an upper surface of the structural member, and the resonator portion is provided with a vertical surface (29C) opposing a vertical surface of the structural member.