A multi-stage reconfigurable air intake and exhaust system for a piston engine having first and second rows of cylinders forming a V configuration. The system includes plural stage packages having inter-related components that can be connected and changed to form different air intake and exhaust gas configurations. There is particularly provided a Stage 1 package with first and second exhaust manifolds adapted to be respectively secured to the first and second rows of cylinders, and a Stage 2 package with a turbo exhaust manifold adapted for mounting a turbocharger, and also adapted to be secured to the first row of cylinders in lieu of the first exhaust manifold, and a crossover pipe assembly adapted for coupling the turbo exhaust manifold to the second exhaust manifold.

An exhaust system for an internal combustion automotive engine, comprising: a left exhaust tract connected or to be connected to a left group of cylinder of the internal combustion automotive engine and a right exhaust tract connected or to be connected to a right group of cylinder of the internal combustion automotive engine, the left and right exhaust tracts, each comprising a branching structure defining a tract inlet, at least one exhaust outlet directly or indirectly opening into atmosphere, and an interconnecting outlet interconnecting said left and right exhaust tracts, wherein said interconnecting outlets are interconnected with each other by a common exhaust gas cleaning and/or silencing device downstream said interconnecting outlets such that exhaust gas flows coming from said interconnecting outlets are unified within said common exhaust gas cleaning and/or silencing device.

An exhaust system for an internal combustion engine of a motor vehicle includes a single exhaust-gas inlet line, two exhaust-gas outlet lines connected in an exhaust gas-conducting manner to the exhaust-gas inlet line, and an active silencing device. The active silencing device is connected in a sound-conducting manner to the two exhaust-gas outlet lines. Furthermore, a motor vehicle with such an exhaust system is provided.

An exhaust gas aftertreatment system is disclosed. The system may include an inlet to receive an exhaust gas produced by an engine and a first section to receive the exhaust gas from the inlet. The system may include a mixing tube to receive the exhaust gas from the first section and a reductant injector to inject a reductant into the mixing tube. The system may include a second section to receive the exhaust gas from the mixing tube and to facilitate mixing of the reductant and the exhaust gas after the exhaust gas exits the mixing tube and a diffuser to receive the exhaust gas from the second section. The system may include a plurality of catalysts to receive the exhaust gas from the diffuser and at least one outlet to receive the exhaust gas from the plurality of catalysts.

The temperature of exhaust gas discharged from a compact air-cooled engine used as a power source for an engine-driven working machine is reduced. An engine has a muffler mounted directly to the exhaust opening of the cylinder, and a resin muffler cover covering the muffler. An exhaust gas restriction member is provided to a wall surface of the muffler, and two exhaust passages serving as outlets for exhaust gas are formed in the exhaust gas restriction member. The exhaust passages are arranged independent of each other, and the streams of discharged exhaust gas are discharged to be slightly separated from each other as the streams flow away from the exhaust openings. The separated streams of discharged exhaust gas form a negative pressure space between the streams promoting the introduction of a cooling air stream into the negative pressure portion. Thus, the temperature of the exhaust gas can be reduced.

A cross-pipe exhaust assembly includes: a first inlet collector splitting into an upper outlet and a lower outlet; a second inlet collector splitting into an upper outlet and a lower outlet; a first outlet collector joining an upper inlet and a lower inlet into a single outlet of the first outlet collector; a second outlet collector joining an upper inlet and a lower inlet into a single outlet of the second outlet collector; a first inline conduit located between the first inlet collector and the first outlet collector; a second inline conduit located between the second inlet collector and the second outlet collector; a first crossover conduit extending between the first inlet collector and the second outlet collector; and a second crossover conduit extending between the second inlet collector and the first outlet collector.

A variable valve for a muffler may include an actuator; a valve tube having an inlet into which exhaust gas is flowed, and a first outlet and a second outlet into which the exhaust gas is discharged, and installed in a middle of a tail pipe into which the exhaust gas is discharged from a muffler; and a valve body in a ball shape rotatably installed in the valve tube, and rotatable by a rotational force delivered from the actuator to block the inlet, or to communicate the inlet with a selected one of the first outlet and the second outlet according to a rotated state of the valve body.

A pulse exhaust pipe for use with diesel engines an end of the pulse exhaust pipe is in communication with eight cylinders, and another end is in communication with two turbochargers; the pulse exhaust pipe includes three exhaust pipe sections which are separated from each other, each exhaust pipe section discharging to a turbocharger independently, wherein a first exhaust pipe section is in communication with a first and second cylinder, while a second exhaust pipe section is in communication with a third to a sixth cylinder, and a third exhaust pipe section is in communication with a seventh and eighth cylinder. The pulse exhaust pipe may prevent the backward flow of exhaust gas and inlet air back flow, thus increasing inflation efficiency and improving the uniformity of each cylinder. Also provided is a diesel engine installed with said pulse exhaust pipe.

An exhaust system for an internal combustion automotive engine, such as a V engine or boxer engine, includes a left exhaust tract connectable to a left group of cylinders and a right exhaust tract connectable to a right group of cylinders. Each exhaust tract includes a tract structure defining a tract inlet for receiving exhaust gas ejected from the group of cylinders to which the exhaust tract is connectable, at least one exhaust outlet opening into the atmosphere, and a connection pipe extending between the tract inlet and the exhaust outlet. The connection pipe includes an inlet aperture for receiving exhaust gas from the tract inlet and an outlet aperture for transferring exhaust gas towards the exhaust opening. The left and the right connection pipes are joined to realize a pipe junction such that the connection pipes form a common connection aperture for transferring exhaust gas and the exhaust system includes at least one valve member for opening or closing the common connection aperture.

Provided is an exhaust device connected to an engine body. The exhaust device includes a plurality of independent exhaust pipes, each of which has a circular cross section, and which are connected to exhaust ports of cylinders of the engine body; and a mixing pipe having a circular cross section, connected to downstream ends of the independent exhaust pipes, and through which exhaust gas that has passed through the independent exhaust pipes flows in. The independent exhaust pipes are connected to an upstream end of the mixing pipe in such a manner that parts of internal spaces of the circular cross sections overlap each other in a predetermined section from the downstream ends of the independent exhaust pipes toward upstream, and a ratio of overlapping portions of the circular cross sections gradually increases from upstream toward downstream.