An engine capable of reducing the content of hydrocarbon in exhaust gas is provided. When viewed parallel to cylinder center axes, tangential virtual lines extending from endpoints of curved port central axes along tangent lines of the endpoints pass intake valve ports, straight port central axes extending from the endpoints of the curved port central axes are further away from a partition wall than the tangential virtual lines, and intake air bent through curved ports passes straight ports and is sucked through the intake valve ports along the wall between the cylinders.

A two-stage water-lift and water separation muffler for use with marine electrical generators installed onboard marine vessels. A first stage water-lift muffler has internal tunable sound suppression structure to provide a first stage of exhaust silencing, and a second stage water separator having internal tunable sound suppression structure to provide a second stage of exhaust silencing while separating entrained cooling water from exhaust gases. The combined first stage water-lift muffler and second stage water separator include internal baffling and silencing structure which is easily adaptable to different generator configurations thereby allowing for structural adjustments to the muffler to optimize sound suppression and minimize backpressure for particular generator and/or exhaust conditions.

A two-stage water-lift and water separation muffler for use with marine electrical generators installed onboard marine vessels. A first stage water-lift muffler has internal tunable sound suppression structure to provide a first stage of exhaust silencing, and a second stage water separator having internal tunable sound suppression structure to provide a second stage of exhaust silencing while separating entrained cooling water from exhaust gases. The combined first stage water-lift muffler and second stage water separator include internal baffling and silencing structure which is easily adaptable to different generator configurations thereby allowing for structural adjustments to the muffler to optimize sound suppression and minimize backpressure for particular generator and/or exhaust conditions.

A disposing method for an inlet pipe in a muffler that includes an outer shell, an inlet pipe, and a separating plate, the disposing method comprising: a first step of inserting the inlet pipe into the outer shell from an opening at one end of the outer shell; a second step of disposing the inlet pipe by moving the inlet pipe within the outer shell in a direction substantially orthogonal to the direction of insertion of the inlet pipe; and a third step of disposing the separating plate by inserting the separating plate into the outer shell from the opening at the other end of the outer shell.

A muffler assembly including a central common active control valve may include a central body for guiding exhaust gas discharged from an engine to flow in bilateral directions in a branched manner, the central body comprising the active control valve disposed in a flow path of exhaust gas, and a pair of main mufflers, each separately disposed at opposite sides of the central body to exhaust exhaust gas introduced from the central body, in which the flow path and an exhaust path of the exhaust gas may be variable based on opening and closing of the active control valve.

An exhaust muffler to be attached to an engine body includes a casing that includes: a rear member facing the engine body and a front member opposing to the rear member while maintaining a gap between the front member and the rear member, the gap forming a path in which exhaust gas discharged from the engine body flows; at least one guiding member that is disposed in the gap of the casing, extends from the rear member to the front member, and has a through-hole into which a fastening member that fastens the casing to the engine body is inserted; and a catalyst holding member that holds a catalyst that purifies the exhaust gas and is accommodated in the gap of the casing while being supported by the at least one guiding member.

An air exhausting device includes a muffler internally divided into a plurality of chambers by a separator, an inlet pipe that couples an exhaust pipe of an engine to the muffler, and an outlet pipe that is a path to discharge an exhaust gas inside the muffler to outside air. The muffler is configured of an expansion chamber to which a downstream end of the inlet pipe opens, and a resonator chamber communicated with only the expansion chamber via a plurality of resonator pipes. Any of or both of lengths and thicknesses of the plurality of resonator pipes are different.

A vehicle exhaust system component includes an exhaust tube defining an exhaust gas flow path, a side branch tuning tube connected to the exhaust tube at an interface, and a porous structure associated with the exhaust tube to reduce noise generated at the interface. In one example, the porous structure comprises a perforated orifice in the exhaust tube. In another example, the porous structure comprises a mesh screen or mesh sleeve.

A muffler comprises a plurality of tubes disposed within an inner chamber. The holes are at least partially punched through the tubes so that hanging chads extend into the tubes at each hole. The tubes form a serpentine flow-path through the chamber through which exhaust flows. One or more diffusion brackets are also disposed within the chamber and downstream from one or more tube outlets.

A sound deflecting muffler for deflecting and absorbing sound waves associated with exhaust gases of an internal combustion engine includes a casing having a muffler body defining an interior area and defining an inlet opening operatively connected to the internal combustion engine for receiving exhaust gases into the interior area and defining an outlet opening in communication with the interior area for directing the exhaust gases downstream from the interior area. The casing includes a pair of sound baffles that define a flow path for the exhaust gases flowing between the inlet and outlet of the muffler body, each sound baffle being perforated and having an arcuate configuration such that the flow path narrows at a midpoint. A first sound deflector is positioned in the flow path proximate the inlet end so as to deflect a portion of the exhaust gases toward the pair of sound baffles.