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.

An improved engine exhaust extractor improves internal combustion engine performance and efficiency. The exhaust extractor includes coaxial inner and outer tubes separating a flow into an inner flow inside the inner tube and an outer flow between the tubes and merging near the exhaust extractor outlet. Helically oriented vanes extend radially from an outer face of the inner tube and reliefs are cut into the inner tube to allow gasses to flow to the outer flow. The inner tube is held in place by end pieces connecting the inner tube to the outer tube. The end pieces include fan blades with wing shaped cross-sections to increase the velocity of exhaust gasses flowing through the exhaust extractor. The fan-like supports and helically oriented vanes cause the outer flow to rotate about a central axis. The exhaust extractor is constructed from only six parts requiring only two welds.

An exhaust gas system is provided for an internal combustion engine having at least a first and a second cylinder. A first exhaust gas pipe is associated with the first cylinder and a second exhaust gas pipe is associated with the second cylinder. A first muffler is associated with the first exhaust gas pipe and a second muffler is associated with the second exhaust gas pipe. A first muffling pipe branches off from the first exhaust gas pipe upstream of a first shut-off element, and is fed through the first muffler and leads into the second exhaust gas pipe downstream of a second shut-off element. A second muffling pipe branches off from the second exhaust gas pipe upstream of the second shut-off element, and is fed through the second muffler and leads into the first exhaust gas pipe downstream of the first shut-off element.

An intake system of an engine includes an engine and an intake manifold. The intake manifold defines individual intake air passageways each connecting one of cylinders to a volume chamber. Each of the individual intake passageways includes a first route and a second route. The first route has a natural frequency, of an air column, synchronized with a first revolution higher than an engine revolution for maximum torque such that a dynamic supercharging effect is obtained at the first revolution. The second route has a natural frequency, of an air column, synchronized with a second revolution higher than the engine revolution for maximum torque such that a dynamic supercharging effect is obtained at the second revolution. The second revolution differs from the first revolution. A difference between the first and second revolutions is set lower than or equal to 15% of a maximum engine revolution.

Methods and systems are provided for a pressure-charged combustion engine having at least one cylinder head comprising at least two cylinders. In one example, a system may include each cylinder having at least one outlet port, at least two cylinders configured to form two groups each comprising at least one cylinder, exhaust lines joined together to form an overall exhaust line which provides an exhaust manifold, the exhaust lines connected to an exhaust turbocharger and equipped with rotor blades wherein each rotor blade comprises a first inlet edge facing the flows and a second inlet edge facing the flows connected to one another at a connection point forming an inflection.

Methods and systems are provided for a pressure-charged combustion engine having at least one cylinder head comprising at least two cylinders. In one example, a system may include each cylinder having at least one outlet port, at least two cylinders configured to form two groups each comprising at least one cylinder, exhaust lines joined together to form an overall exhaust line which provides an exhaust manifold, the exhaust lines connected to an exhaust turbocharger and equipped with rotor blades wherein each rotor blade comprises a first inlet edge facing the flows and a second inlet edge facing the flows connected to one another at a connection point forming an inflection.

A snowmobile including: a frame; an engine supported by the frame; an exhaust pipe connected to the engine; and a turbocharger connected to the exhaust pipe. The turbocharger includes a bypass conduit fluidly communicating with the turbocharger housing and including an exhaust inlet fluidly connected to the exhaust pipe; a valve in the bypass conduit for controlling the flow of exhaust gas, and an exhaust collector. The valve is movable between first and second positions, a first flow path passing through the exhaust inlet, through the bypass conduit, and into the exhaust collector, a second flow path passing through the exhaust inlet, through the bypass conduit, through the exhaust turbine, and into the exhaust collector, in the first position, a majority of the exhaust gas flowing along the first flow path and in the second position, a majority of the exhaust gas flowing along the second flow path.

The present invention uses the exhaust gas of an internal combustion reciprocating engine to drive a turbine. The turbine is position around the cylinder. The turbine is connected to systems that will use the energy to improve the total system efficiency. One such system would be connected to a compressor to create the force induction required for two-stroke engines.

The present invention uses the exhaust gas of an internal combustion reciprocating engine to drive a turbine. The turbine is position around the cylinder. The turbine is connected to systems that will use the energy to improve the total system efficiency. One such system would be connected to a compressor to create the force induction required for two-stroke engines.

Methods and systems are provided for exhaust leak management in an engine. The exhaust leakage management system may include a port disposed to capture leaked exhaust along a movable portion associated with a turbine. The exhaust leakage management system may also include a three-way valve at a bifurcation of the port, directing leaked exhaust either to a first passage fluidically connected to a crankcase of the engine or to a second passage fluidically connected to a downstream portion of an exhaust pipe, depending on engine operating conditions.