Abstract: An expansion pipe for an engine which has a curved tubular body, a first connector for connecting an interior of the body to an exhaust part of the engine, and a second connector which is used for connecting an interior of the body to an exhaust gas treatment device and which has the same configuration as the first connector.

Abstract: An exhaust processor has an exhaust tube and a cover mounted for rotation at least partially around the exhaust tube to adjust the tuning frequency of the exhaust processor. A method of operating the exhaust processor is also disclosed.

Abstract: A device for engine exhaust extraction improves engine performance and efficiency. The device includes outer and inner tubes sharing a central axis. The inner tube is held in place by supports connected between the inner tube and the outer tube, which supports have a fan-like orientation. Helically oriented vanes reside on an outer surface of the inner tube, which vanes extend outward. An inlet flow separates into an outer flow between the inner tube and the outer tube and an inner flow inside the inner tube. The fanblade-like supports and helically oriented vanes cause the outer flow to rotate about the central axis of the device. The flow recombine near the device outlet.

Abstract: An exhaust system for an internal combustion engine having two banks of cylinders by which pulses of exhaust gas are alternately directed to a diverter subassembly. The diverter subassembly, which is located in the muffler, includes a perforated gas decelerator chamber which divides each pulse of exhaust gas between two exhaust outlets and causes a low pressure wave to occur in the exhaust system to enhance scavenging of a subsequent pulse of exhaust gas and thereby improve engine performance and mileage. The muffler further includes one or more cores and may or may not include a dead air space chamber to provide attenuation and tonal balance to the exiting exhaust gas.

Abstract: A double pipe exhaust manifold includes an inner pipe, an outer pipe formed in a cylindrical shape by joining at least one side edge thereof by welding, a space retaining member disposed in an annular space defined between the inner pipe and the outer pipe, a connection pipe connecting to a exhaust gas recirculation valve, and a mesh ring. Opening holes are formed in the inner pipe and the outer pipe so that the opening holes are opposed to each in a radial direction of the pipes. The connection pipe is connected to the opening hole of the outer pipe. The mesh ring is interposed between the inner pipe and the outer pipe in a state that the mesh ring plugs an annular opening part defined between opening edges of the opening holes.

Abstract: A particulate filter (22) for removing particulates included in an exhaust gas discharged from a combustion chamber (5) is arranged in an engine exhaust passage. The particulate filter has wall partitions (54) which the exhaust gas can pass through. The particulates included in the exhaust gas are removed by oxidation in the interior of the partitions. The particulates are fluidized in the interior of the partitions.

Abstract: An exhaust water trap assembly has separated and spaced exhaust tubes, and a dome cap blocking entry of water to protect an upstream catalytic converter or soot filter. A first tube extends axially upwardly into a housing, and a second tube is spaced vertically thereabove. The dome cap on the top end of the first tube blocks exhaust flow axially upwardly therepast and blocks entry of water axially downwardly therepast.

Abstract: Sound and power are an important part of the motorcycling experience. From the early days people have been attempting to get it “right” and have tried numerous ways to achieve the best of both worlds. Generally one had to be sacrificed to some degree to get the other. Tuning the exhaust rather than tuning the carburetor or increasing cubic inches is a less expensive and more efficient way to get both the sound and midrange power that motorcyclists are looking for. With the Exhaust Enhancement exhaust pipes can be tuned for sound and increased midrange power very simply and easily by installing them in the exit end of an aftermarket straight type pipe using various combinations to achieve a desired sound and not sacrifice power.

Abstract: An exhaust system for an internal combustion engine of an outboard motor is provided. The exhaust system provides dual exhaust passages, simplifying the engine's construction and reducing manufacturing costs, while optimizing engine performance. The exhaust system includes exhaust ports having equal lengths that avoid differential pressure losses across cylinders. The arrangement of the exhaust passages enables a cowling to have a tapered aerodynamic design.

Abstract: An exhaust pulse control unit (10) for increasing exhaust manifold vacuum in an engine comprises an inlet (11), an outlet (12) and an intermediate containment zone (13). An exhaust pulse capture and expansion zone (14) is located between the inlet and intermediate zone and a merging zone (17) between the intermediate zone and the outlet. The capture and expansion zone may consist of two stages with the first stage providing a relatively rapid increase in exhaust gas volume.

Abstract: An exhaust system for an internal combustion engine having a first cylinder and a second cylinder from which pulses of exhaust gas exit and are routed along separate paths towards the exhaust mufflers. The exhaust system independently routes the pulses of exhaust gas from the two cylinders. The exhaust gases that are expelled from the first cylinder are routed through a first exhaust pipe. The exhaust gases that are expelled from the second cylinder are routed through a second exhaust pipe assembly. The second exhaust pipe assembly routes the exhaust gasses from an exhaust port for the second cylinder laterally across the motorcycle to achieve a true dual exhaust system. The second exhaust pipe assembly provides an approximate equal length flow path as compared to the path used by the exhaust gasses that are expelled from the first cylinder.

Abstract: An exhaust system for use with a four-stroke engine having first and second cylinders. The cylinders generate exhaust pulses at uneven time intervals with respect to each other. The exhaust system includes a muffler and first and second exhaust pipes that communicate between the mufflers and the first and second cylinders, respectively. The first and second pipes being sized and shaped to deliver the exhaust pulses to the muffler at even time intervals with respect to each other.

Abstract: The invention is an adjustable exhaust system and an adjustable insert for an exhaust system. The exhaust system includes a header flange, at least one conduit coupled to the header flange, a collector coupled to the conduit, and an adjustable insert for tuning engine performance.

Abstract: The intake and exhaust control systems are operable in varying modes, according to the engine speed, by a single actuator. The intake control system includes an intake valve that allows a variable amount of air into an air cleaner depending on vehicle speed. The exhaust control system includes an exhaust control valve, and a primary and a secondary exhaust purifying system located downstream of the exhaust control valve. The flow into the exhaust purifying systems may also be controlled according to engine speed.

Abstract: Sound and power are an important part of the motorcycling experience. From the early days people have been attempting to get it "right" and have tried numerous ways to achieve the best of both worlds. Generally one had to be sacrificed to some degree to get the other. Tuning the exhaust rather than tuning the carburetor or increasing cubic inches is a less expensive and more efficient way to get both the sound and midrange power that motorcyclists are looking for. With the Exhaust Enhancement exhaust pipes can be tuned for sound and increased midrange power very simply and easily by installing them in the exit end of an aftermarket straight type pipe using various combinations to achieve a desired sound and not sacrifice power.

Abstract: An exhaust system for a two-cycle internal combustion engine combusting a normally gaseous hydrocarbon as fuel, the engine having a cylinder having an exhaust port in communication with an exhaust manifold. The exhaust system has an exhaust gas inlet connectable to the exhaust manifold of the internal combustion engine and an exhaust gas outlet spaced from the exhaust gas inlet in the direction of flow of exhaust gas through the system. A first tubular portion is disposed between the exhaust gas inlet and outlet, the first tubular portion diverging in the direction of flow. A second tubular portion is disposed between the exhaust gas inlet and outlet and spaced from the first tubular portion in the direction of flow, the second tubular portion converging in the direction of flow.

Abstract: A number of embodiments of acoustical devices for improving either or both the intake and exhaust sounds emanated from an internal combustion engine. This is achieved by employing acoustical devices which are configured so as to discharge the desired sound waves to the atmosphere rather than by attempting to dampen the undesired sound waves generated in the system.

Abstract: An exhaust processor comprises a Helmholtz resonance chamber with a variable tuning throat. The tuning frequency of the exhaust processor changes as the outlet opening from the variable tuning throat into the Helmholtz resonance chamber changes.

Abstract: A induction exhaust system, for an internal combustion engine, capable of the multi step processes of 1) scavenging the chamber of exhaust gases and free radicals, 2) breaking the scavenge vacuum wave behind each energetic exhaust pulse, releasing said free radicals and the overscavenged air fuel vacuumed from the intake manifold during valve overlap, and 3) induction of such free radicals, unburned fuel, and fresh matter including atmospheric air.

Abstract: An internal combustion engine, especially of a two-stroke engine in a portable handheld work apparatus, includes an outlet (27) for the exhaust gases which is fluidly connected with at least one inlet opening (13, 14) in an exhaust-gas muffler (1). At least one resonance pipe (6, 7) is mounted in flow direction between the outlet (27) from the engine (20) and the inlet opening (3, 5) into the exhaust-gas muffler (1) in order to obtain a good noise attenuating result and simultaneously make possible an advantageous, space-saving mounting of the engine (20).

Abstract: A silencer for silencing and also for filtering exhaust gases, contains at least one acoustic resonator chamber (13, 14, 15, 16) (Helmholtz frequency), at least one porous body (7, 8) the porous body (7, 8) occupying at least part of the chamber and at least one connecting passage (17) for leading gas from each one of the acoustic chamber wherein the connecting passage (17) extend along the outher surface of the porous body, so as to lead along a helical flow path (19).

Abstract: A two-stroke internal combustion engine (1) is provided with a muffler device (2). In one example, the engine (1) is intended for a working tool, such as a chain saw or a trimmer. A pipe (3), which either is straight or bent, and having an adapted or tuned length and a closed outer end (4), is arranged in connection to the engine's exhaust port (5) as well as an outlet (6), which leads the exhaust gases to the surrounding air. By this arrangement of the pipe (3) and the outlet (6) the scavenging losses are reduced and thereby the specific fuel consumption is reduced and cleaner exhaust gases are achieved.

Abstract: The present invention discloses a compact efficient exhaust handling device that is particularly advantageous for use with small two-stroke, piston-type internal combustion engines, which device provides both exhaust scavenging and charge densification in the cylinder of the engine by utilizing a first muffler section formed in a helical or wrapped configuration, and a muffler expansion chamber also formed in a wrapped configuration, and axially displaced from the first section.

Abstract: Temperature control system for marine engine exhaust system. The control system lowers flow of cooling water to water jacket and exhaust gas conduit of the exhaust system at low engine speeds. The control system is typically activated at and below a predetermined engine speed. Once activated, the control system operates to reduce flow of cooling water to the exhaust system. The control can operate in an on/off mode, or can modulate rate of flow of water through the exhaust system, or both. However the water flow is limited, a predetermined minimum flow of cooling water is maintained through the exhaust system, at least either at periodic intervals, or at a constant but lowered rate, to maintain cooling in the exhaust system on rubber components of the exhaust system.

Abstract: An exhaust performance chamber is provided as in interstitial interfitting member or housing which mates between the conventional exhaust manifold exit and tail pipe entrance. The engine typically utilized with the exhaust performance chamber is a high frequency very small engine having a speed of about 30,000 to 35,000 revolutions per minute. Interposing the exhaust performance chamber into a conventional exhaust stream having a manifold and exhaust pipe connection requires an additional seal and perhaps a lengthened spring to complete the exhaust train starting from a standard configuration. The modular property facilitates multiple change-outs to determine the best configuration for a given engine and terrain. In a first embodiment, a chamber is provided ahead of an orifice. In a second embodiment, an expansion chamber is formed. The use of the performance chamber has been shown to increase fuel efficiency and increase low end or initial movement power performance.

Abstract: A device for silencing a flowing gas which includes a valve housing in which a valve is mounted. A separate pressure regulator is provided which is in communication with the flowing gas and which is responsive to gas pressure to thereby influence movement of a mechanical actuating device which controls movement of the valve such that the valve may be opened at least two different rates dependent upon the pressure of the flowing gas.

Abstract: An exhaust pulse control unit (10) for increasing exhaust manifold vacuum in an engine comprises an inlet (11), an outlet (12) and an intermediate containment zone (13). An exhaust pulse capture and expansion zone (14) is located between the inlet and intermediate zone and a merging zone (17) between the intermediate zone and the outlet. The capture and expansion zone may consist of two stages with the first stage providing a relatively rapid increase in exhaust gas volume.

Abstract: An exhaust processor comprises a Helmholtz resonance chamber with a variable tuning throat. The tuning frequency of the exhaust processor changes as the outlet opening from the variable tuning throat into the Helmholtz resonance chamber changes.

Abstract: An exhaust processor has an exhaust tube and a cover mounted for rotation at least partially around the exhaust tube to adjust the tuning frequency of the exhaust processor. A method of operating the exhaust processor is also disclosed.

Abstract: An exhaust pipe has a manifold; one end of the manifold is connected to a distal end of a connecting tube. Another ends of the manifold are extended with a left branch tube and a right branch tube. The left branch tube is connected to a first muffler tube and the right branch tube is connected to a second muffler tube. The feature is that an interior of a middle section of the manifold has a valve which is controlled by a controller. The valve controls the area of the opening of the left branch tube communicated with the first muffler tube and the area of the opening of the right branch tube communicated with the second muffler tube. The driver may control the variation of exhaust gas without needing to adjust the exhaust pipe. The noise may be reduced easily and the performance of acceleration is enhanced.

Abstract: The tunable resonator is coupled to the engine speed control such that the resonator is set to a different frequency range when the engine speed is changed. The frequency range is changed by opening and closing necks and/or changing the effective volume of the resonator.

Abstract: A tuned exhaust system for a multi-cylinder, reciprocating, internal combustion engine is disclosed. Each exhaust tube has approximately the same overall length resulting in a predetermined resonant frequency. The overall length includes the sum of the header tube length and the internal length of the collector assembly portions of the exhaust channels in the heat exchanger box. Calculating the correct length and bending the pipes to fit in the space available resulted in increased horsepower, reduced fuel consumption, cooler cylinder head temperatures, reduced noise and vibration for four-cylinder and six-cylinder aircraft engines.

Abstract: An exhaust gas recovery system for an internal combustion engine recovers the high heat energy generated by an exhaust gas clarification catalytic converter intermediately disposed in the exhaust system of the internal combustion engine as electrical energy without causing an increase in exhaust gas resistance. A stack device in a heat-driven type sound wave generating portion is provided at a one end of a resonance pipe. The resonance pipe is disposed adjacently to an exhaust gas clarification catalytic converter intermediately disposed in the exhaust system. A first end portion of the stack is heated by the heat generated by the catalytic converter, thereby providing the stack with a temperature gradient. A transducer for converting a sound wave generated by the sound wave generating portion attendant on the temperature gradient into electrical energy is provided at the other end portion of the resonance pipe.

Abstract: A partitioning member for dividing a connecting pipe into at least two exhaust passageways is provided in the connecting pipe, which is attached to an exhaust side of a silencer. A valve mechanism is operable to vary the passageway area of one of the exhaust passageways. With this structure, for example, when an engine is rotating at low revs, exhaust gas is discharged from the exhaust passageway without the valve mechanism, while when the engine is rotating at high revs exhaust gas is simultaneously discharged from the exhaust passageway having no valve mechanism and a passageway provided with the valve mechanism. Therefore, it is possible to reduce exhaust noise when the engine is rotating at low revs.

Abstract: A number of embodiments of acoustical devices for improving either or both the intake and exhaust sounds emanated from an internal combustion engine. This is achieved by employing acoustical devices which are configured so as to discharge the desired sound waves to the atmosphere rather than by attempting to dampen the undesired sound waves generated in the system.

Abstract: An exhaust system for an internal combustion engine of an outboard motor is provided. The exhaust system provides dual exhaust passages, simplifying the engine's construction and reducing manufacturing costs, while optimizing engine performance. The exhaust system includes exhaust ports having equal lengths that avoid differential pressure losses across cylinders. The arrangement of the exhaust passages enables a cowling to have a tapered aerodynamic design.

Abstract: An exhaust system for an internal combustion engine having a first cylinder and a second cylinder from which pulses of exhaust gas exit and are routed along separate paths towards the exhaust mufflers. The exhaust system independently routes the pulses of exhaust gas from the two cylinders. The exhaust gases that are expelled from the first cylinder are routed through a first exhaust pipe. The exhaust gases that are expelled from the second cylinder are routed through a second exhaust pipe assembly. The second exhaust pipe assembly routes the exhaust gasses from an exhaust port for the second cylinder laterally across the motorcycle to achieve a true dual exhaust system. The second exhaust pipe assembly provides an approximate equal length flow path as compared to the path used by the exhaust gasses that are expelled from the first cylinder.

Abstract: A resonator provided for air system that includes a body defining a passageway. A wall is disposed within the chamber and the wall and the chamber are movable relative to one another to define a length and a volume of the cavity. The length and the volume of the cavity define a noise attenuating frequency. By moving the wall and chamber relative to one another the noise attenuating frequency may be changed as the frequency changes during the engine operation. The drive mechanism moves the wall in the chamber relative to one another to change the noise attenuating frequency. The chamber may be a branched type resonator or an inline type resonator. Accordingly, the above described invention provides a resonator that may be adjusted during engine operation to attenuate noise over a variety frequencies.

Abstract: The present invention discloses a compact efficient exhaust handling device that is particularly advantageous for use with small two-stroke, piston-type internal combustion engines, which device provides both exhaust scavenging and charge densification in the cylinder of the engine by utilizing a first muffler section formed in a helical or wrapped configuration, and a muffler expansion chamber also formed in a wrapped configuration, and axially displaced from the first section.

Abstract: An exhaust system for an internal combustion engine having two banks of cylinders by which pulses of exhaust gas are alternately directed to a diverter subassembly. The diverter subassembly, which is located in the muffler, includes a perforated gas decelerator chamber which divides each pulse of exhaust gas between two exhaust outlets and causes a low pressure wave to occur in the exhaust system to enhance scavenging of a subsequent pulse of exhaust gas and thereby improve engine performance and mileage. The muffler further includes one or more cores and may or may not include a dead air space chamber to provide attenuation and tonal balance to the exiting exhaust gas.

Abstract: An exhaust system for a two-cycle internal combustion engine combusting a normally gaseous hydrocarbon as fuel, the engine comprising a cylinder having an exhaust port in communication with an exhaust manifold. The exhaust system comprises an exhaust gas inlet connectable to the exhaust manifold of the internal combustion engine and an exhaust gas outlet spaced from the exhaust gas inlet in the direction of flow of exhaust gas through the system. A first tubular portion is disposed between the exhaust gas inlet and outlet, the first tubular portion diverging in the direction of flow. A second tubular portion is disposed between the exhaust gas inlet and outlet and spaced from the first tubular portion in the direction of flow, the second tubular portion converging in the direction of flow.

Abstract: A two-stroke internal combustion engine (1) is provided with a muffler device (2). In one example, the engine (1) is intended for a working tool, such as a chain saw or a trimmer. A pipe (3), which either is straight or bent, and having an adapted or tuned length and a closed outer end (4), is arranged in connection to the engine's exhaust port (5) as well as an outlet (6), which leads the exhaust gases to the surrounding air. By this arrangement of the pipe (3) and the outlet (6) the scavenging losses are reduced and thereby the specific fuel consumption is reduced and cleaner exhaust gases are achieved.

Abstract: An exhaust header system for an internal combustion engine having improved exhaust gas flow characteristics. Primary pipes extend from openings in a flange bolted to the engines exhaust ports. The primary pipes come together at a collector pipe into which the primary pipes extend slightly. The ends of the primary pipes are substantially parallel, uniformly spaced around the collector pipe axis and have end surfaces lying substantially in a single plane. A generally pyramidal transition piece has a base corresponding to, and secured to, the primary pile end surfaces so as to cover the area between the pipe ends. The pyramid apex extends along the collector pipe centerline toward the exit end. The length and cross section of the transition piece is selected to provide a smooth transition from the greater combined internal cross section of the primary pipe ends to the lesser cross section of the collector pipe exit end.

Abstract: A method of manufacturing a exhaust system for an internal combustion engine having two banks of cylinders by which pulses of exhaust gas are alternately directed to a crossfire assembly. The crossfire assembly, which is located in the exhaust system, includes a gas accelerator chamber which divides each pulse of exhaust gas between two secondary exhaust outlets and causes a low pressure wave to occur in the exhaust system to enhance scavenging of a subsequent pulse of exhaust gas and thereby improve engine performance.

Abstract: An internal combustion engine, which can be disposed in a water vehicle, includes an exhaust system having features improving the performance, ease of manufacturing, and/or the water preclusive effects thereof. The exhaust system can include an exhaust manifold defining a plurality of exhaust runners and being made from at least two parts. The exhaust system can also include a plurality of individual exhaust passages extending from exhaust ports of the engine to a forward end of the engine. The exhaust system can also include an exhaust passage which extends from the exhaust ports to varying elevations relative to the exhaust ports, as well as other features.

Abstract: Heat shielding panels are attached to exhaust pipes and a silencer by using small set springs and large set springs. Distortion on a heat shielded panel, which would be caused when attaching a heat shielding panel through welding, is not caused. A process for positioning a bracket, which would be required when welding a bracket to an exhaust pipe, can be omitted. Moreover, as no bolt and nut is used, the number of parts can be reduced. As a result, productivity can be improved and an increase in the cost can be suppressed.

Abstract: The intake and exhaust control systems are operable in varying modes, according to the engine speed, by a single actuator. The intake control system includes an intake valve that allows a variable amount of air into an air cleaner depending on vehicle speed. The exhaust control system includes an exhaust control valve, and a primary and a secondary exhaust purifying system located downstream of the exhaust control valve. The flow into the exhaust purifying systems may also be controlled according to engine speed.

Abstract: A method of tuning a vehicle includes measuring a plurality of inlet and outlet frequency responses at the inlet and outlet ports, respectively. The inlet and outlet responses each include an amplitude response and phase response. The method also includes determining inlet and outlet transfer functions that include amplitude and phase responses. An interior noise spectrum is determined and the engine air in/out system is modified based on the interior noise spectrum to result in a different interior noise spectrum.

Abstract: A method of tuning a vehicle includes measuring a plurality of inlet and outlet frequency responses at the inlet and outlet ports, respectively. The inlet and outlet responses each include an amplitude response and phase response. The method also includes determining inlet and outlet transfer functions that include amplitude and phase responses. An interior noise spectrum is determined and the engine air in/out system is modified based on the interior noise spectrum to result in a different interior noise spectrum.

Abstract: An exhaust pipe for motor vehicle muffler having a plurality of muffling holes arranged over the periphery, a partially perforated conical tube suspended on the inside and axially extended from the exhaust gas input end thereof for accelerating exhaust gas passing through, and a plurality of spiral portions formed integal with the periphery thereof and spaced around the conical tube for turning exhaust gas escaped from peripheral through holes on the conical tube into a spiral flow.