Abstract: An exhaust gas cooling system for a vehicle includes a cooling fin system retrofit and a side exhaust pipe retrofit having an exhaust gas exit pipe having a first portion having a plurality of mixing portions which are either bends or internal mixing fins configured to mix vehicle exhaust gas, but not to restrict exhaust gas flow, a second portion fastened to the first portion and a chrome coated third portion fastened to the second portion and extending along the side of the vehicle. The cooling fin system retrofit includes an adjustable clamp and one or more cooling fins, each cooling fin having a base having a pair of upstanding arms, with one arm of the pair having a lip for engaging an arm of another cooling fin. An exhaust gas cooling system kit, a side exhaust pipe retrofit kit, a cooling fin kit are included.

Abstract: An exhaust gas system of a multi-cylinder internal-combustion engine has two groups of cylinders and one exhaust pipe system respectively and has a connection pipe between the exhaust pipe systems which is arranged close to the engine and which is constructed as a resonance pipe. The connection pipe can be shut off and opened up as a function of at least one operating parameter of the internal-combustion engine. By way of this connection pipe serving as the resonance pipe, resonance vibrations can be generated between the two exhaust pipe systems as a function of the ignition sequence and the rotational speed of the internal-combustion engine. Should these resonance effects cause a deterioration in the course in the torque as a function of the rotational speed, the switching flap is closed. When a positive effect is caused, the switching flap is opened up.

Abstract: An exhaust pipe assembly for a multi-cylinder internal combustion engine is made up of a plurality of exhaust pipes made of steel whose upstream ends are connected to a flange provided for connection to a cylinder head, a collecting case to which downstream ends of the exhaust pipes are connected, and a coupling flange interposed between the exhaust pipes and the collecting case. The coupling flange is made of a thin steel plate and has upward burred portions which are circular in shape and into which respective downstream ends of the exhaust pipes are separately inserted for welding with the burred portions, and a downward bent portion whose peripheral edge portion is fitted onto an upper outside end portion of the collecting case for welding with the bent portion.

Abstract: An exhaust manifold for an internal combustion engine includes a set of exhaust manifold conduits. Pairs of the exhaust manifold conduits converge and are joined at their downstream portions. The pairs of exhaust manifold conduits are connected to associated downstream exhaust pipes. In each pair, a first exhaust manifold conduit having a first downstream portion extends into the exhaust pipe, and a second exhaust manifold conduit having a second downstream portion terminates at the inlet end of the exhaust pipe. A channel is defined by the body of the exhaust pipe and the flat side wall of the first downstream portion. The channel has a cross-sectional configuration approximately the size and shape of the second downstream portion and communicates with the second downstream portion. Each exhaust manifold conduit includes an inner pipe disposed within an outer pipe for reduced thermal dissipation to promote a quicker light-off of the catalytic converter.

Abstract: An exhaust system for an internal combustion engine. A plenum chamber has two ports, one which is connected to a header tube for conducting a stream of exhaust gas and another which is connected to a ram tube adapted to collect outside air provided by movement of a vehicle in which the internal combustion engine is installed. The plenum chamber is constructed so that the outside air is caused to travel thereinside at least a substantially non-zero set-back distance before being permitted to join the stream of exhaust gas. Preferably, the exhaust system also includes one or more reverse flow controllers associated with respective cylinders of the internal combustion engine, downstream from the exhaust ports thereof.

Abstract: An exhaust system for an internal combustion engine used in a marine propulsion system is provided with a water injection system by which water can be injected into the exhaust system. An engine control unit, which comprises a micro-processor, is used to select the rate of water injection into the exhaust system as a function of several predefined parameters. For example, engine speed and throttle position can be used by the micro-processor in the engine control unit to select a predefined rate of water flow into the exhaust system by selecting a predefined valve position, for an electronically controlled valve, that has been preselected and stored in the micro-processor.

Abstract: An exhaust gas cooling system for a vehicle includes a cooling fin system retrofit and a side exhaust pipe retrofit having an exhaust gas exit pipe having a first portion having a plurality of mixing portions which are either bends or internal mixing fins configured to mix vehicle exhaust gas, but not to restrict exhaust gas flow, a second portion fastened to the first portion and a chrome coated third portion fastened to the second portion and extending along the side of the vehicle. The cooling fin system retrofit includes an adjustable clamp and one or more cooling fins, each cooling fin having a base having a pair of upstanding arms, with one arm of the pair having a lip for engaging an arm of another cooling fin. An exhaust gas cooling system kit, a side exhaust pipe retrofit kit, a cooling fin kit are included.

Abstract: An exhaust pipe for an internal combustion engine has non-circular passages that extend from the engine exhaust port to the atmosphere. The performance of the engine is not impaired by the non-circular passages compared with prior pipes having circular passages of the same cross sectional areas at corresponding locations along the pipes. The non-circular cross section enables two or more passages to be located inside a single outer wall. Plates inside the outer wall divide the outer wall interior into the separate passages. Adjacent passages thus share a wall. The exhaust pipe includes headers that conduct exhaust gasses directly from the engine to the associated passages. In a modification of the invention, an exhaust pipe is tuned for performance at two different engine operating speeds by tuning a passage on one side of a shared wall differently than another passage on the other side of a shared wall.

Abstract: A collector is disclosed for the primary pipes of an exhaust manifold in an internal combustion engine. The collector includes a common cavity and a plurality of primary pipes having a first cross-sectional area at their outlet ends and second cross-sectional area at an upstream location, the first cross-sectional area being less than the second cross-sectional area, with the primary pipes being in direct contact with the common cavity of the collector and further arranged to include a single central pipe with the remainder of the pipes spaced around the central pipe, with the outlet of the central pipe being formed as a conically tapering portion and the outer wall of the central pipe forming part of the inner wall of the remainder of the pipe.

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 snowmobile having a lightweight fabricated frame assembly. The frame assembly includes a number of reinforcing elements, some of which comprise heat exchangers for the liquid cooling system of the engine, so as to provide high rigidity and light weight. The engine of the snowmobile is provided with an exhaust system that permits a relatively short effective length, but minimizes pulse-back effects by forming internal expansion chambers around the exhaust branch pipes. The drive for the snowmobile includes a reversing transmission and a brake assembly associated therewith in addition to a main brake assembly for the snowmobile. Furthermore, there is provided a parking brake assembly that is easy to operate and which will provide the operator with a visual and physical warning of its condition so that the operator will not attempt to operate the snowmobile with the parking brake engaged.

Abstract: An exhaust manifold with several inlet ports and a combination of diffuser and nozzle portions associated with each inlet port for producing a high flow rate and a low pressure drop from entry to exit. The diffuser and nozzle portions are in series and designed into the manifold at each inlet port and slightly upstream of the next downstream positioned inlet port. The diffuser portion decreases the velocity of exhaust gasses as they enter the manifold and are then turned substantially ninety degrees into a longitudinal direction of the manifold. This diffuser action slows the velocity and reduces pressure losses as the turn of exhaust flow is accomplished. The next in series nozzle portion increases the velocity of exhaust gases to cause the flowstream to jump past a neighboring downstream engine exhaust port. Resultantly, the flow through the manifold is improved and the pressure drop decreased which enhances engine performance.

Abstract: An exhaust system for an engine having at least four exhaust ports firing in sequential order. The exhaust system includes an exhaust manifold having two collector sections which extend in substantial part in parallel side-by-side relationship to provide a compact construction. Each collector section is served by a pair of branch portions that communicate with respective cylinders where the cylinders collected firing at least 270 degrees from each other to minimize the effect of the exhaust pulses from one cylinder on the other cylinders.

Abstract: An improved header assembly for use in V-8 engines. In engines having eight cylinders, performance can be unexpectedly improved by utilizing an improved header assembly whereby the exhaust gas from each of cylinders 4 and 7 is routed by means of a by-pass tube to a specific area in a second stage collector while the exhaust gas from the remainder of the cylinders is routed to a first stage collector. Such an arrangement of tubes routing exhaust gas into first and second stage collectors creates smooth, non-turbulent exhaust gas flow through the collector resulting in greater engine horsepower and torque.

Abstract: Curved inlet pipes, which themselves are assembled from at least two curved individual pipes, are provided in an exhaust manifold with sheet metal inlet pipes from the respective cylinder head outlet to a common exhaust gas outlet. As a result, the sum of the moments of resistance is substantially smaller, especially in the case of short, curved inlet pipes, which prolongs the service life of a sheet metal exhaust manifold.

Abstract: An exhaust manifold of which each exhaust port is formed by a pipe member is disclosed. Each pipe member at one end portion has a wedge shape section. Each pipe member at the other end portion is connected to the cylinder head of an engine. The pipe members are abutted one another in the one end portion to form the merging portion of the exhaust manifold. A plurality of radial partition walls are formed in the merging portion by joining end surfaces of the pipe members one another. In the exhaust manifold, two adjacent partition walls among the partitions walls are arranged almost symmetrically around a plane which passes through the center of the merging portion and is parallel to a direction in which the largest force is generated by thermal expansions of the exhaust ports.

Abstract: A collector system for exhausts that uses a junction to merge the an engine's primary tubes in a linear arrangement. Thus, all exhaust gas passes cleanly through the unit with no interference or creating any hot spots than can fail. To help remove exhaust gas from the junction portion of the collector, a venturi pipe is installed in the system. This venturi acts to scavenge the junction pipe of any remaining exhaust before the next impulse come through the system. Finally, to eliminate the complex welding of the primary tubes and to guarantee a seal, a tube sheet is used. This tube sheet accepts each of the primary tubes. Each pipe is then welded to the tube sheet, which then fits over the end of the collector junction. The tube sheet is then welded to the junction and the system is sealed.

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 lean burn engine adapted to establish a specified air-fuel ratio leaner by predetermined rate than a stoichiometric air-fuel ratio in a range of low engine speeds and low engine loads is provided with an air intake system of a low speed type which provides a high charging efficiency in a range of low engine speeds and an exhaust system capable of eliminating a nitrogen oxide emission in the exhaust even during lean burning.

Abstract: An exhaust system for a "V"-type engine having front and rear banks of cylinders each containing two cylinders is disclosed. The exhaust system includes a pair of cylinder heads and exhaust pipes connected thereto. Each cylinder head has two exhaust ports corresponding to the two cylinders of that bank. The exhaust ports in the front cylinder head face forwardly and lie in planes which intersect one another along a line offset to the right of a centerline of the cylinder head. Similarly, the exhaust ports in the rear cylinder head face rearwardly and lie in planes which intersect one another along a line offset to the left of a centerline of the head. Each offset is preferably equal to half of the distance between planes containing the front and rear camshaft timing chains. An exhaust pipe extends outwardly from each exhaust port in the front cylinder head, bending inwardly and downwardly and extending to the rear of the motorcycle.

Abstract: An exhaust collector for collecting exhaust gases from a multiple cylinder combustion engine to a common flow includes primary tubes. To reduce mass and heat losses in the exhaust system, the peripheral walls of the collector are at least to a substantial part formed by the primary tubes.

Abstract: A collecting portion for an exhaust manifold branch where a combined pipe portion including a plurality of pipes is welded to a collecting pipe wherein, (1) an intermediate member is provided between the combined pipe portion and the collecting pipe, (2) the collecting pipe has a portion that extends upstream, (3) a weld line formed at the downstream end of a partitioning wall is axially zigzagged, (4) a weld line is offset from the downstream surface of the combined pipe portion, (5) only one of the partitioning walls is curved, (6) downstream ends of the partitioning walls are smoothly convex, (7) an additional weld is formed in the partitioning wall, or (8) an intermediate member is welded at a half circumference of the combined pipe portion.

Abstract: An exhaust system for an internal combustion engine having an exhaust port and an exhaust chamber communicating between the ports includes a variable dimension element in the exhaust chamber adapted to vary an effective dimension of the exhaust chamber during operation of the engine.

Abstract: A reciprocating piston internal combustion engine. The engine includes a cylinder having a cylinder wall, and at least one intake port and at least one exhaust port. At least one intake valve is disposed at a corresponding intake port, and at least one exhaust valve is disposed at a corresponding exhaust port. A piston has a diameter D and is mounted for reciprocal motion of a predetermined stroke length S within the cylinder, the piston further being adapted to assume a bottom dead center position and a top dead center position. The engine further includes a plurality of manifold tubes having an intake manifold tube and an exhaust manifold tube. Each of the manifold tubes includes a plurality of pipes connected end to end and having an end pipe disposed closest to a corresponding port. Each of the pipes has a constant cross-section, the cross section of the pipes increasing incrementally in a direction away from the end pipe.

Abstract: To provide an exhaust pipe structure capable of arranging a plurality of exhaust pipes in a restricted space inside a cover and suppressing the discoloring of the cover due to an increase in the temperature of the cover. Each of a plurality of exhaust pipes introduced from each cylinder of a multi-cylinder engine includes a double-pipe structure of an outer pipe and an inner pipe. The exhaust pipes pass inside the cover in such a manner that at least one exhaust pipe near the inner side surface of the cover is left as being of the double-pipe structure, and at least each of the remaining exhaust pipes has a portion of a single-pipe structure.

Abstract: An arrangement for silencing the exhaust gases discharged from a multi-cylinder internal combustion engine, wherein the exhaust gas is discharged in first and second streams from separate exhaust gas manifolds on opposite sides of the engine and the two streams traverse a different but equal lengthed path to be combined into a single stream to be presented to exhaust system components, such as catalytic converters and separate mufflers. In one embodiment, the streams pass through conduits integrally formed, in part, with through structure of a muffler. In other embodiments, the stream paths are equalized by being passed through conduits formed in closed shells.

Abstract: A connector is provided for joining two upstream exhaust pipes with a downstream exhaust pipe and for substantially offsetting any difference in length that may exist in the upstream exhaust pipes. The connector includes first and second external shells that are secured on opposite respective sides of an internal divider plate. The external shells and internal plates cooperate to define unequal travel lengths within the connector to offset the unequal travel lengths of the upstream exhaust pipes leading to the connector. The two separate exhaust flows with travel lengths equalized by the connector converge with one another into a chamber defined by the connector, and exit from the connector through an outlet. Expansion of the converging exhaust gas streams into the chamber contributes to acoustical tuning of the exhaust system. The equal lengths of the respective exhaust gas streams also facilitates acoustical tuning performed by a downstream muffler.

Abstract: An exhaust control system having a plurality of exhaust manifolds is configured and arranged such that combustion of exhaust gases flowing therethrough is unhibited to the extent that the concentration of major pollutants (CO, HC, NO.sub.x) exiting from the tail pipe and into the environment is substantially reduced. The exhaust system utilizes pairs of primary pipes defining an upstream portion of an exhaust manifold which are coupled to exhaust ports whose respective valves provide fluid flow communication to only one of the primary pipes at any moment in time. A secondary pipe defining an downstream portion of the exhaust manifold is coupled to the outlet of the primary pipes through a connector. One-way valves permit atmospheric air surrounding the exhaust manifold to be drawn into each primary pipe proximate its inlet, and into the secondary pipe proximate the connector.

Abstract: An outboard motor comprising a lower unit including an outer housing and an inner exhaust housing mounted within the outer housing, the inner exhaust housing defining an exhaust chamber, the upper end of the inner exhaust housing having therein spaced first and second exhaust inlets, and the inner exhaust housing also including a first exhaust pipe having an upper end communicating with the first exhaust inlet and having a lower end communicating with the exhaust chamber, a second exhaust pipe having an upper end communicating with the second exhaust inlet and having a lower end communicating with the exhaust chamber, and a connecting exhaust pipe having opposite first and second ends respectively communicating with the first and second exhaust inlets, the connecting pipe being open only at the opposite ends, and a two-stroke internal combustion engine including first, second, third and fourth cylinders and first, second, third and fourth exhaust gas ducts having respective first ends communicating respective

Abstract: An exhaust system for an internal combustion engine includes a conduit in fluid communication with a combustion chamber for transferring exhaust gases from the combustion chamber. The exhaust system also includes a port disposed along the conduit for admitting supplemental air into the conduit so that the supplemental air combines with the exhaust gases and flows immediately in a direction downstream from the combustion chamber to draw the exhaust gases from the combustion chamber and to increase combustion of the exhaust gases.

Abstract: A compact, high performance exhaust assembly (50) for an internal combustion engine (20) or the like having a balanced chamber (52). Two substantially parallel inlet exhaust pipes (38, 40) are mounted to a first wall (74) of the chamber (52) and are axially aligned with, but independent of, two output exhaust pipes (54, 56) similarly mounted to a opposing second wall (76) of the chamber (52). Exhaust gas is discharged through the inlet pipes (38, 40), preferably in an out-of-phase relationship or alternating from one inlet pipe to the other. The exhaust gas passes a short distance through the chamber (52) and out of aligned outlet pipes (54, 56). The majority of the exhaust gas flows directly through the chamber (52) without significant expansion. The exhaust assembly (50) increases the power output of the engine.

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: The specification related to an intake/exhaust air pressure balancer connected to an intake apparatus and/or an exhaust apparatus of an internal combustion engine and a method of reducing the intake/exhaust air pressure resistance. The intake/exhaust air pressure balancer in this invention is essentially consisted of a storage tank and a bypass pipe. Minimization of an intake air pressure resistance can be achieved by temporarily storing an intaken air reversely flowed at the end of an intake stroke followed by reintake of the air into a cylinder during the next intake stroke, while minimization of an exhaust gas pressure resistance can be expected by temporarily storing a rapidly expanding exhausted gas discharged during an exhaust stroke followed by redischarge through an exhaust equipment under a reduced exhaust gas pressure.

Abstract: A header assembly for an internal combustion engine including a pair of header pipes having discharge ends, a collector mounted on the discharge ends and having a housing directing exhaust gas pulses from both of the pipes to an outlet. The collector is formed to produce the flow of exhaust pulses in a manner fluid coupling out-of-phase exhaust gas pulses in each of the pipes to the others by an amount sufficient to increase horsepower of the engine at substantially all normal operating speeds. The header pipes proximate the inlet to the header collector are formed for discharge of gases along a common interface or boundary of substantial transverse length to effect fluid coupling. Additionally, the collector is free of channeling or protrusions to permit unconstrained transverse expansion of the pulses across the adjacent header pipe. A method of increasing engine horsepower by fluid coupling together header pipes also is described.

Abstract: An automotive vehicle header system is described as incorporating a collector having pipes of inside diameter slightly greater than the outside diameter of the pipes exiting from the engine heads which are coupled to it. This permits a removable insertion of one set of pipes into the other, for ease of installation and later servicing of the engine and vehicle, and allows for a sliding of the collector towards, or away from, the engine as desired, to controllably adjust available torque and/or horsepower. In a preferred embodiment of the invention, the lengths for the collector pipes are individually selected so as to equalize the total lengths of all pipes from the engine cylinders to the output end of the collector.

Abstract: An engine has first and second cylinder rows substantially parallel to each other and is mounted sideways so that the cylinder rows are arranged side by side in the longitudinal direction of the vehicle body with the first cylinder row disposed forward of the second cylinder row. An exhaust system for the engine has first and second exhaust pipes. The first exhaust pipe is connected to the cylinders in the first cylinder row on the front side of the first cylinder row and is led rearward of the engine through a recess formed on the lower side of an oil pan of the engine which is positioned between the first and second cylinder rows. The second exhaust pipe is connected to the cylinders in the second cylinder row on the rear side of the second cylinder row, is once led forward into the recess of the oil pan and then turned rearward in the recess to extend rearward. The first and second exhaust pipes are merged into a common exhaust pipe at a junction in the rear of the engine.

Abstract: This invention relates to a dual-exhaust system for an internal combustion automotive engine. Instead of just the usual direct channeling of exhaust gases from the engine towards the muffler, the system of the invention also couples the exhaust flow from one pipe to the other, and vice versa, mixing and equalizing the pressures in the two pipes, by the addition of two further pipes connected between the first two in an X-configuration.

Abstract: A five cylinder two cycle outboard motor includes exhaust tuning of the five in-line cylinders. Exhaust tuning of five in-line cylinders provides increased horsepower for the five cylinder two cycle outboard motor. The five cylinder outboard motor which produces 150 horsepower achieves an ideal horsepower to number of cylinders and provides the proper horsepower size/weight size outboard motor for bass fishing and water skiing boats.

Abstract: An internal combustion engine having a valve overlapping period control device for controlling a valve overlapping period during which both the intake valve and the exhaust valve are open, and an equivalent length adjustment device for controlling an equivalent length of an exhaust passage necessary to cause an exhaust gas pulsation to return to an exhaust port in the form of a vacuum during the valve overlapping period, to thereby reduce the equivalent length as an engine speed increases when the valve overlapping period is longer than a predetermined period, and for stopping a control of the equivalent length when the valve overlapping period is shorter than the predetermined period.

Abstract: Disclosed herein is a two stroke internal combustion engine comprising first, second, third, and fourth cylinders which fire in a predetermined sequence and which include respective first, second, third, and fourth exhaust ports which open and close in response to piston movement, and an exhaust gas discharge system communicating with the exhaust ports, including a duct portion, and being operable, in response to opening of one of the exhaust ports, to afford passage of exhaust gas from the one exhaust port to the exhaust gas discharge system so as to provide an outgoing positive acoustical pressure wave which travels in the duct portion and which arrives at the exhaust port of the previously fired cylinder prior to closure of the exhaust port of the previously fired cylinder and to provide a returning negative acoustical pressure wave which travels in the duct portion after substantial completion of the travel of the outgoing positive acoustical pressure wave in the duct portion and which arrives at the one

Abstract: An exhaust system for internal combustion engines includes at least two exhaust passages, each passage communicated with at least one branch exhaust passage of an exhaust manifold communicating exhaust ports of a multiple-cylinder engine, and a confluent exhaust passage disposed downstream of said at least two exhaust passages, said confluent exhaust passage including a confluent point for converging downstream ends of said at least two exhaust passages. The exhaust system also includes a communication passage substantially parallel with the at least two exhaust passages and a valve disposed in the communication passage, for allowing a portion of exhaust gas flow to bypass said confluent point only when the engine is within a predetermined high engine revolution range.

Abstract: In a spark ignition or compression ignition four cycle internal combustion engine, an exhaust expansion chamber is sized to produce a reflected exhaust pressure wave timed to an auxiliary reopening of the exhaust valve after the intake valve has effectively closed. The reflected exhaust pressure wave causes the re-entry into the cylinder of a quantity of intake charge (which has previously been drawn into the expansion chamber) subsequent to the effective filling of the cylinder through the intake valve, the result being a boost in cylinder charge and pressure on the compression stroke of the piston. At engine design speed, the power output of the engine is substantially improved over the power output without the boost in cylinder charge and in compression stroke pressure. The particular exhaust expansion chambers and valve re-opening timing is adaptable to single and multiple cylinder four cycle engines.

Abstract: The disclosure is directed to an exhaust efficiency increasing apparatus incorporating crossover ducts between dual exhaust conduits extending from an engine having two cylinder banks. The ducts are disposed to communicate with upstream entry and downstream exit apertures on the exhaust conduits and cross in an "X". Since where the ducts are positioned affects engine torque, torque curves can be adjusted or changed by adjustably positioning the crossover ducts within a housing which is placed in the exhaust system, to move the crossover ducts nearer to or further from the engine, by computer or manual control. A second embodiment incorporates at least two spaced duct pairs disposed to increase low end torque and high end output.

Abstract: An exhaust outlet conduit for internal combustion engines and adapted to function as a resonator for exhaust waves exiting from the cylinder or cylinders to which the conduit is connected. The conduit (4) is characterized by a combination of features, according to which the conduit exhibits an exhaust throughflow area which increases outwardly from the end of the conduit connected to the cylinder (1), and the conduit wall has provided therein one or more openings (5). The openings are so configured that the total opening area increases along the conduit in a direction away from the cylinder (1), so as to increase the frequency range over which the conduit (4) will function as a resonator.

Abstract: An exhaust supercharging arrangement for a two-cycle internal combustion engine having groups of cylinders each of which merge into respective exhaust manifolds. The exhaust manifolds communicate with each other and the firing order is such that the one cylinder of one group is on its scavenge cycle when another cylinder of the other group is on its exhaust cycle for minimizing the torque and heating loading on the engine.

Abstract: An exhausting apparatus for a four-cycle four-cylinder engine having four cylinders each provided with an exhaust port comprises four exhaust pipes connected to corresponding exhaust ports of the engine cylinders. The four exhaust pipes are classified into first and second groups in accordance with ignition timings and the first and second groups of two exhaust pipes each are shifted in connection with the ignition timings by means of an angle of 360.degree. with respect to each other. Exhaust chamber members including two exhaust chambers each, are in communication with front portions of the exhaust pipes respectively through means of communication holes and two communication pipes, one connecting the first group of the exhaust pipes and the other connecting the second group of the exhaust pipes.

Abstract: Self-suctioning apparatus for multi-cylinder piston engines uses a tube-like pipe system extending from the manifold of the engine and includes a diverter for dividing the waste gas stream into several partial streams with the diverted waste gas streams being reflected and focused on an inner wall of the pipe system to form a zone of hot waste gases which are received by a nozzle system with no waste gas flow reversal to provide an uninterrupted suctioning effect and a continuous gas flow with a higher degree of air charging and an exit tube receiving the continuous gas flow for discharge into the ambient.

Abstract: A number of embodiments of exhaust control devices particularly adapted for use with motorcycles and wherein the exhaust control device is designed to be positioned beneath the engine transmission assembly of the motorcycle and which offer a compact configuration. In each embodiment, the expansion device is formed of a fabricated member from sheet metal stampings. The exhaust device comprises an inlet or collector section an expansion chamber and an outlet. In some embodiments, both the inlet collector section conduits are formed from joined stampings and the expansion chamber is formed from joined stampings and in other embodiments only the expansion chamber is formed from joined stampings and the inlet conduits of the collector section are formed from formed tubular members.

Abstract: Embodiments of outboard motors incorporating improved exhaust gas systems for preventing the ingestion of water into the cylinders of an alternate firing multiple chamber internal combustion engine. The exhaust passages are provided with a restricted communication with each other at a point that is above the water under all running conditions so as to prevent water ingestion. In one embodiment, the exhaust passages communicate with an above the water exhaust gas discharge independently of each other and the restricted communication is provided between the passages by a restricted opening in an exhaust pipe. In another embodiment, the exhaust pipe forms an expansion chamber and the individual exhaust passages communicate with this expansion chamber at points close to each other through restricted openings for providing the communication.

Abstract: Disclosed herein is a two stroke internal combustion engine comprising first, second, third, and fourth cylinders which fire in a predetermined sequence and which include respective first, second, third, and fourth exhaust ports which open and close in response to piston movement, and an exhaust gas discharge system communicating with the exhaust ports, including a duct portion, and being operable, in response to opening of one of the exhaust ports, to afford passage of exhaust gas from the one exhaust port to the exhaust gas discharge system so as to provide an outgoing positive acoustical pressure wave which travels in the duct portion and which arrives at the exhaust port of the previously fired cylinder prior to closure of the exhaust port of the previously fired cylinder and to provide a returning negative acoustical pressure wave which travels in the duct portion after substantial completion of the travel of the outgoing positive acoustical pressure wave in the duct portion and which arrives at the one