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: A method of lining an exhaust manifold is disclosed, comprising the steps of applying a thin layer of a heat-resistant compound to the interior of an exhaust manifold and bonding the compound to the manifold. The manifold may be in two or more sections when the compound is applied and the sections may subsequently be joined together to form the manifold. The compound may contain zirconium and/or may be a ceramic material.

Abstract: A method lining a component of a vehicle which may contact exhaust gases is disclosed, including the steps of applying a thin layer of a heat-resistant compound to an inner surface of the component to form a liner therein and bonding the liner to the surface. The manifold may be in two or more sections when the compound is applied and the sections may subsequently be joined together to form the component. The compound may contain zirconium and/or may be a ceramic material.

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 hood covering the space between cylinder banks of an internal-combustion engine which are arranged in a V-shape is provided for the gastight enclosure of a ram pipe arranged in an area between cylinder banks and exhaust pipes leading the fuel gases from the cylinders to the ram pipe. At this type of a hood, sealing surfaces are obtained with respect to the crankcase as well as with respect to the cylinder heads. The hood can be constructed with a central hood part which is fastened to the crankcase and only has contact surfaces with respect to the crankcase, but not with respect to the cylinder heads. Wedge-shaped hood parts, which are constructed in the form of elbows, are arranged in a V-shaped opening between the central hood part and the cylinder heads and are pulled into the V-shaped opening by means of necked-down bolts. Common sealing surfaces exist with the cylinder heads and the central hood part.

Abstract: A turbo-charged internal combustion engine having the cylinders communicating with exhaust passages that merge into common outlets that are disposed midway between the exhaust passages and which lie in a common plane. A cooling jacket encircles these exhaust passages and is divided by a wall into upper and lower portions.

Abstract: A heat insulating ceramic insert-cast article for an internal combustion engine, comprising a ceramic liner and a metallic member enclosing an outer periphery of the ceramic liner. The ceramic liner is adapted to contact exhaust gases. A joint boundary between the ceramic liner and the metallic member is constituted by contact faces at which the ceramic liner contacts the metallic member and heat insulating air layers at which the ceramic liner and the metallic member do not contact each other. A process for producing such a heat insulating ceramic insert-cast article is also disclosed. First, the outer periphery of the ceramic liner is covered with the heat insulating layer which is partially formed with cuts, and then the ceramic liner is enclosed with a molten metal in the state that the ceramic liner is covered with the layer.

Abstract: An exhaust manifold for a multicylinder type internal combustion engine, which comprises a plurality of branch tubes each having one end adapted to connect with an exhaust port of the engine; a gas gathering tubular member having the branch tubes connected thereto thereby to lead the exhaust gases produced by the engine thereinto through said branch tubes; and an outlet tube connected to the gas gathering tubular member to discharge the gases therefrom, wherein at least two of the branch tubes are integral with the gas gathering tubular member.

Abstract: An exhaust system is provided for internal combustion engines which relatively improves the performance and reduces noise output of such engines. The system comprises a plurality of exhaust pipes which are operably flow connected to exhaust ports of the engine at one end thereof and to discharge pipes through a collection chamber at an opposite end thereof. The discharge pipes include a silencing device in the discharge ends thereof. A feedback mechanism is provided to divert a slip portion of the sonic wavefront and/or mass exiting through an exhaust pipe back toward the exhaust port associated with an interconnected exhaust port or in such a manner as to delay passage of the slip portion out of the discharge pipes or to delay the slip portion and direct same to a different discharge pipe for discharge. The feedback mechanism may be valve and computer controlled so as to add or delete the feedback as required to maximize operation of the engine and/or assist in operation of a vehicle powered by the engine.

Abstract: A number of embodiments of exhaust arrangements for two cycle multiple cylinder internal combustion engine. In each embodiment, the cylinder block has exhaust ports that communicate with the cylinder bores and extend through a side surface of the cylinder block. This side is closed by a cover that forms a manifold for receiving the exhaust gases and lengthening the distance between the port and the junction with the manifold. In line and V-type embodiments are disclosed.

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 placing the crossover ducts near one end of a housing which is placed in the exhaust system and which can be reversed, end-to-end, to position the crossover ducts nearer to or further from the engine.

Abstract: The present invention provides methods to take advantage of the exhaust gas pulses in an exhaust system of a multi-cylinder internal combustion engine to increase the volumetric efficiency over the complete operating range of the engine. It solves the problems of other systems which are only able to gain a beneficial effect from the exhaust gas pulses over a limited range of the engine operating speeds, by providing a means of varying the exhaust pipe lengths, combinations, and cross-sectional area of the exhaust passages of the multi-cylinder internal combustion engine. By this means it provides an exhaust system in which the exhaust gas pulse frequencies can be varied over the entire operating range of the engine to obtain desirable pulse frequencies matching the cylinder exhaust timing for efficient extraction of the exhaust gases, improvement in volumetric efficiency and a higher maximum engine speed.

Abstract: An exhaust system for a V-type six-cylinder engine having first and second banks each having three engine cylinders. The exhaust system includes first and second exhaust systems which are respectively connected to the first and second banks to be supplied with exhaust gas from the engine cylinders. Each exhaust system includes an exhaust tube connecting a catalytic converter and a muffler. The exhaust tubes of the first and second exhaust systems are communicated at a predetermined position by a communicating pipe member. The predetermined position corresponds to location of antinodes of the resonance sound pressure modes in the respective first and second exhaust systems which modes are reverse in phase to each other, so that resonance frequencies in exhaust noise are cancelled thereby to effectively achieve exhaust noise reduction.

Abstract: There is disclosed a cover unit of an exhaust manifold device in which sound-and-heat shielding covers are attached via bosses to upper and lower parts of exhaust manifold inlet ducts integral with flanges secured to a cylinder head. The cover unit has such a structure that when securing the flanges to the cylinder head, a portion, of a lower cover, on which a tool inserted to rotate bolts for fastening the flanges impinges undergoes a predetermined amount of deformation to admit insertion of the tool.

Abstract: An exhaust-manifold heat insulating board is provided which has an insulating layer sandwiched between an inner layer and an outer layer. The inner and outer layers are laminated together and have an inner area and a peripheral area. The inner area has a depression with end portions formed therein and the peripheral area is formed into connecting tab portions which are positioned adjacent the end portions. Each of the connecting tab portions has a length greater than the width of the adjacent end portion of the depression.

Abstract: An internal combustion engine designed to use gas as fuel. Exhaust valve (2) operation is effected via: (i) a push rod of two parts, the respective ends of which are pivoted to an intermediate connector sliding in a bore in the cylinder head and (ii) two rocker arms (11 and 16). Fulcrum point (18) of rocker (16) may be adjusted to reduce exhaust valve lift during part throttle operation or alternatively exhaust braking during overrun conditions may be achieved by cracking open valve (2) on the compression stroke: this is effected by inward movement of wedge (21) or by a cam raising the end of rocker (16). Modifications of exhaust manifold, rocker shaft mounting, etc are also described.

Abstract: Herein disclosed is an improved exhaust manifold for an internal combustion engine, which comprises an outer body of aluminium having a configuration corresponding to the exhaust manifold, and insulating layer of ceramic fiber disposed on the inner surface of the outer body for protecting the outer body from the heated exhaust gas, and a protecter incorporated with the insulating layer in a manner to maintain the disposition and configuration of the insulating layer.

Abstract: An inner line (11) conducting the exhaust gases is arranged within a gas-tight housing (12, 13) surrounding the inner line (11) with a spacing. The inner line (11 l ) is assembled of individual sections (15) whereby the length of a section (15) corresponds approximately to the cylinder spacing of the piston internal combustion engine. Each section (15) of the inner line (11) consists of two channel-shaped parts (15a, 15b) which with flanges (18, 19) formed-on at the two longitudinal edges resting one upon the other form between them the line cross section. The flanges (18, 19) of the channel-shaped parts are secured at the surrounding housing (12, 13) by bolts (22, 23). The manufacture of the inner line (11) from sheet metal under avoidance of welded connections permits a particularly economic manufacture and results in a weight-saving type of construction.

Abstract: A marine drive exhaust system (10, 12, 14) is provided with resilient, shaped rubber O-ring seals (20, 74) between facing surfaces (16, 18) of the exhaust manifold (10) and exhaust elbow (12), and the facing surfaces (70, 72) of the exhaust elbow (12) and the exhaust pipe (14). Each of the shaped O-ring seals has an inner peripheral rib (22, 76) extending peripherally around the exhaust passage and generally conforming to the shape thereof and being spaced laterally between the exhaust passage and the peripheral water passages. Each of the shaped O-ring seals has an outer peripheral rib (28, 82) extending peripherally around the water passages and spaced laterally outward of the inner rib by a gap (30, 84) through which the water passages extend.

Abstract: An exhaust manifold includes an inner shell providing a first flange having an interior and exterior surface and an outer shell cooperating with the inner shell to define an interior region therebetween. The outer shell provides a second flange having an exterior surface which is situated in spaced-apart relation to the interior surface of the first flange to form a flange-receiving space therebetween. The flange-receiving space provides an access opening into the interior region intermediate the inner and outer shells. At least one baffle is situated in the interior region. The at least one baffle includes a mounting flange nested between the first and second flanges and positioned in the flange-receiving space to extend through the access opening so that a distal portion of the mounting flange is exposed to exterior surroundings outside of the interior region defined by the inner and outer shells. Configuration of the at least one baffle is disclosed for use in single and dual exhaust manifolds.

Abstract: An internal combustion engine is provided with a sound-insulating enclosure (2), which defines a sealed passage extending through the enclosure. A passage which extends through the enclosure is sealed by a sealing ring (9), which consists of a rubber-elastic material and is disposed between an inner flanged ring (7), which is secured to the engine, and an outer flanged ring (8), which is secured to the enclosure (2). In order to provide sealing means which are satisfactory for a passage for the exhaust manifold (3), the inner flanged ring (7) carries a protective shield (10), which shields the inside surface of the sealing ring (9) and which defines with the sealing ring (9) a clearance (12), which contains a heat-resisting and sound-absorbing insulating material (11).

Abstract: A manifold which is mounted either on the intake side or on the exhaust side of an internal combustion engine. A main body of a manifold is divided into an end manifold, at least one intermediate manifold and a base manifold. Branch pipes are formed by a bulging process to project upright branch pipes on a side of each manifold, and manifolds are connected on ends with gaskets interposed therebetween so that the bending moment caused by the expansion of metal members due to hot exhaust gases may be absorbed instead of being concentrated on the roots of the manifold to enhance the durability of the manifold.

Abstract: The invention relates to an exhaust system for a multicylinder internal combustion engine comprising at least a manifold formed by individual exhaust ducts connected to the engine's cylinders, connector pipes, into which groups of individual ducts come together, a common exhaust pipe into which the said connector pipes join each other, the silencer mufflers, wherein the system is characterized in that the said silencer mufflers are positioned in correspondence of at least an end of said common exhaust pipe.

Abstract: An exhaust control device for an exhaust system for an internal combustion engine specifically applied to a motorcycle. An exhaust control device is incorporated that includes a single valve body having a plurality of exhaust gas passages that cooperate with each of a plurality of exhaust pipes that extend from the engine to the valve body. Parallel valve shafts are supported in the valve body and support valves that control the flow through the exhaust gas passages.

Abstract: An exhaust system for a multi-cylinder internal combustion engine has a tailpipe (13) which is divided by a partitioning wall or walls (14,15) into separate channels extending at least part-way of the tailpipe from its inlet end and with which the outlets of the primary exhaust channels in the manifold are separately connected. The structure of the exhaust system enables the exhaust system to be easily packaged within the engine compartment of a car, while enabling the lengths of the exhaust channels to be selected to enable advantage to be taken of the resonant phenomena for optimization of the engine torque and other engine characteristics.

Abstract: An exhaust device for use in an internal combustion engine includes a plurality of independent passages each connected to an exhaust port of a respective cylinder of the engine. At least one communicating passage is provided to connect the independent passages to each other at points upstream of a junction where the independent passages are joined together. The communicating passage permits the exhaust gases from one cylinder to flow into the independent passages for the other cylinders, thus lowering the gas temperature and improving fuel comsumption.

Abstract: The invention relates an arrangement for the mounting of exhaust gas lines which are arranged in an exhaust gas-tight space, and serve for the transfer of the combustion gases from the exhaust openings of the cylinder heads to the exhaust gas manifold. By reason of the high temperature load of the exhaust gas lines which are not cooled in the exhaust gas-tight space, the mounting is so constructed that no compulsory forces can occur which stem from the temperature strain. This is achieved by a point-shaped mounting of flanges connected with the exhaust gas lines at only one circumferential place each. The single point fastening assures a radial and axial expansion possibility of the exhaust gas lines under thermal load free of compulsory forces. The exhaust gas lines are threadably secured each by means of fastening bolts within the area of the ends of the cylinder head side preferably at the cylinder head or at wall parts of the components forming the exhaust gas-tight space.

Abstract: An exhaust system is provided for internal combustion engines which relatively improves the performance of such engines. The system comprises a plurality of approximately equal length exhaust pipes which are operably flow connected to exhaust ports of the engine at one end thereof and to a collection chamber at an opposite end thereof. The system further includes discharge pipes which communicate between ambient atmosphere and the collection chamber. The exhaust pipes are grouped in sets such that each of the pipes in the set is generally axially aligned with one of the discharge pipes. The collection chamber has a cross-sectional area which is greater than the cross-sectional area of the exhaust pipes where they are attached thereto and converges to a smaller cross section at the opposite end thereof where the discharge pipes are attached thereto. The discharge pipes diverge away from the collection chamber and include a silencing device in the discharge ends thereof.

Abstract: An improved multi-cylinder engine exhaust header and single exhaust pipe transition element. The transition element comprises separate cylinder exhaust input connections, a gas chamber, a single exhaust gas output and a thin blade member positioned between at least two separate exhaust input connections. The forward end surface of the blade member takes various configurations to aid the mixing of the exhaust gases from each separate cylinder in the gas chamber prior to exit from the exhaust gas output.

Abstract: An improved valve for use in an exhaust system to increase the performance of the engine throughout the entire engine and load speed ranges by providing reflective areas that cooperate with the individual exhaust pipes of the engine to reduce pressure pulses in the combustion chamber during valve overlap periods. A number of embodiments of compact valve constructions are shown that employ relatively short journaling shafts for minimizing the effects of thermal expansion.

Abstract: A number of embodiments of motorcycle exhaust systems including control valves for controlling the effective area of the exhaust pipes and for improving performance by preventing reflections from one exhaust pipe back into the cylinder served by another exhaust pipe. The valve means lies under the engine crankcase and the crankcase is formed with a recess for clearing the valve means and permitting air flow across it for cooling purposes. Various valving arrangements are disclosed as is a skid plate arrangement for protecting the valve means.

Abstract: A process is provided for manufacturing an exhaust manifold. The manifold comprises at least one stamp formed inlet flange, a stamp formed sheet metal inner shell and a stamp formed sheet metal outer shell. The inner shell and outer shell are configured to define an exhaust chamber therebetween. Each inlet flange is stamp formed to define at least one exhaust port extending entirely therethrough, with each exhaust port including a stamp formed projection extending continuously thereabout from one surface of the inlet flange. The inner shell is stamp formed to define an inlet aperture for each exhaust port. The inner shell is projection welded to the inlet flange such that the projections stamp formed therein define the weldments. The outer shell then is welded to the inner shell to define the exhaust chamber of the manifold. An outlet tube may be secured to an outlet aperture of the outer shell.

Abstract: A dual exhaust pipe segment for mounting an oxygen sensor is connected to a dual exhaust manifold of an internal combustion engine. The exhaust pipe segment comprises a communicating portion where the two paths communicate with each other. The communicating portion defines an oxygen sensor mounting location. The exhaust pipe further comprises tapered inwardly facing surfaces upstream of the oxygen sensor installing position. Tapers of the tapered inwardly facing surfaces are determined such that extension of the tapered inwardly facing surfaces tangentially contact an outside surface of the oxygen sensor. As a result of this structure, almost all gas flowing from every cylinder of the engine can contact the oxygen sensor, and the temperatures of gas contacting the oxygen sensor are decreased to an appropriate extent relative to a sensor mounting location inside the dual exhaust manifold.

Abstract: An exhaust apparatus connected to a V-type internal combustion engine which is mounted in an engine compartment in a front part of a vehicle. The exhaust apparatus comprises a front exhaust manifold and a rear exhaust manifold connected to banks of the V-type engine respectively, an exhaust assembly connected to the exhaust manifolds and a catalytic converter interposed in the exhaust assembly. The wall thickness of the front exhaust manifold is made thinner than that of the rear exhaust manifold. By the thin front exhaust manifold, the heat capacity of the front exhaust path extending from the front exhaust manifold toward the catalytic converter is lessened, thereby suppressing the dropping of temperature of the exhaust gas flowing through the front exhaust path. As a result, the dropping of temperature of the exhaust gas reaching the catalytic converter is suppressed as a whole, and a catalyst in the catalytic converter is warmed up quickly to a required temperature.

Abstract: An improved exhaust system for water craft engines is disclosed, which consists in the main an exhaust manifold connected to the cylinder exhaust port of the engine, an exhaust pipe joined at one end to the exhaust manifold and a diffuser connected at one end to the other end of the exhaust pipe and at the other end to the rest of the exhaust system including a muffler and steam separator. The exhaust pipe is divided into two axial parts, the first vertical, largely U-shaped pipe portion for direct connection to the exhaust pipe at downstream thereof and the second horizontal pipe portion for connection at one end thereof to the first pipe portion at downstream thereof and at the opposite end to the diffuser. The second pipe portion is disposed to extend adjacent to the exhaust manifold and made integral therewith in a rigid assembly, with the first pipe portion being releasably secured to the exhasut manifold and second portion through bolts for easy disassembly in servicing.

Abstract: A tuned exhaust manifold is provided for attachment to an engine having a plurality of exhaust ports. The manifold includes an inner and outer shell joined together to form an exhaust chamber and an inwardly-opening flange-receiving space at a split line defined by the union of the inner and outer shells. Captive tuning baffles are dropped in place and positioned in the exhaust chamber to isolate individual engine exhaust ports for engine performance tuning. Each baffle includes a flange trapped in the space between the inner and outer shells to retain the baffle in a predetermined position within the exhaust chamber. The baffles are arranged in a predetermined pattern within the exhaust manifold to define separate passgeways extending from exhaust inlet openings formed in the inner shell toward one or more exhaust openings of the manifold. Tuning is accomplished by configuring and placing the baffles to control the flow of exhaust from each engine exhaust port through the exhaust manifold.

Abstract: A stamped exhaust manifold for a small internal combustion engine having a stamped sheet metal housing including an inlet and an outlet. A sheet metal baffle is located in the housing opposite the inlet and spaced from the housing to form a dead air insulating pocket between the baffle and the housing. The baffle is positioned so that hot exhaust gas entering the manifold from the engine through the inlet port will impinge directly on the baffle and will be deflected thereby through substantially 90.degree. to the manifold outlet port.

Abstract: A particulate trap system for use with a diesel engine includes a first particulate trap in heat exchange relation with the exhaust materials passing through the first exhaust bank, and a second particulate trap similarly located with respect to the second exhaust bank. A first exhaust pipe extends from the first exhaust bank to the inlet of the second trap, while a second exhaust pipe extends from the second exhaust bank to the inlet of the first trap. Each exhaust pipe is sufficiently long to allow some condensation of hydrocarbons in the exhaust materials due to cooling thereof. When the mixture of exhaust gases and condensed hydrocarbons arrives in the respective traps, the temperature is again increased due to the heat exchange taking place, and trap regeneration through combustion takes place.

Abstract: An exhaust manifold for multi-cylinder, opposed piston engines includes a collector, a plurality of conduits, each connecting an exhaust port from a cylinder to the collector and each conduit includes a thermal expansion joint to permit differential thermal expansion between the engine body and the substantially hotter exhaust conduit and thus to avoid undesirable stresses in the conduits. Preferably, the expansion joint is formed by overlapping portions of conduit sections which include axial as well as radial clearances therebetween for thermal expansion. In the event that the engine is to be turbocharged, the manifold can be covered with a thermal blanket to prevent heat losses from the exhaust system. In such a case, the expansion joint includes a resilient seal member between the overlapping conduit portions which seals the conduit sections to each other despite substantially similar thermal growth in each of the insulated blanketed conduit sections.

Abstract: A fastening arrangement of an inner pipe line arranged in a housing adapted to be closed off gas-tight and conducting the exhaust gases, which is easy to assemble and reliable in operation, is attained by plug-in connections. The ends of axially adjacent pipe sections of the inner pipe line are thereby centered in retaining rings. Each retaining ring includes two approximately radially projecting lugs, of which one is constructed as a fixed point and the other as a displaceable coupling.

Abstract: An exhaust manifold for an internal combustion engine wherein exhaust ducts connected to respective engine cylinders are formed of discrete pipe members. A united section has an upstream divergent portion connected to the exhaust ducts and a downstream convergent portion to exhaust pipes. An internal space is defined in the downstream convergent portion and located intermediately between adjacent internal passages in the downstream convergent portion to communicate them with each other. An opening is formed in the peripheral wall of the downstream convergent portion at a location positionally corresponding to the internal space. A flange member has a boss formed thereon and being larger in size than the opening and disposed in face-to-face contact with an outer surface of the peripheral wall of the downstream convergent portion. The boss has a through bore formed therein and aligned with the opening, through which an exhaust constituent concentration sensor is to be inserted.

Abstract: A motor vehicle having a transversely disposed V-type engine with first and second exhaust manifolds associated with the forward and rearward cylinder banks, respectively. An exhaust pipe interconnects both of the exhaust manifolds with a single rearwardly positioned catalytic converter and an auxiliary catalytic converter is positioned in the exhaust pipe so that only the exhaust gases from the forwardmost exhaust manifold pass through it.

Abstract: An exhaust manifold, cylinder head, or the like, is provided with one or more insulating shield members formed within associated housing members having ball or cylindrical end portions. The end portions are seated on bearing rings preferably cast or inserted into the housing ends to provide for relative expansion of the internal shields with respect to the outer housing members, both linear and bending expansion motions being accommodated. The resulting passage assemblies may be formed by casting the housing members around their respective shields. Sand core material may be preapplied to create the desired insulating clearance between the associated members and, if desired, to secure the bearing rings in position.

Abstract: A pair of front exhaust pipes are joined to a rear exhaust pipe by an exhaust pipe joint. The front exhaust pipes have downstream end portions projecting into the exhaust pipe joint so that between the outer walls of the downstream end portions and the inner walls of the exhaust pipe joint there are formed annular spaces for receiving reflected waves travelling in the upstream direction and limiting the propagation of the reflected waves into the downstream ends of the front exhaust pipes.

Abstract: Heat shield assemblies are normally connected to engines which have exhaust systems in order to reduce the temperature of the outer surface. The skin temperature of the outer surface of the heat shield assembly must be cooled so that persons coming in contact with such a surface is not burned. The subject heat shield assembly includes a heat source, an inner member and an outer member which respectively define first and second cooling flow paths. The first cooling flow path being adapted to convect heat away from the heat source and the inner member as air passes therethrough and the second cooling flow path being adapted to convect heat away from the inner member and the outer member as air passes therethrough. The air passing through the first and second cooling flow paths effectively reduces the temperature of the outer member so that no one would be burned upon contact therewith.

Abstract: Disclosed herein is a method of fabricating an integrally cast engine block including a plurality of cylinders, exhaust passage portions which respectively extend from the cylinders and which form portions of exhaust gas passages of equal length, and a water jacket cavity including respective water jacket cavity portions in encircling relation to the exhaust passage portions, which method comprises the steps of providing a mold cavity which defines the exterior surface of the block, locating one or more disposable cores in the mold cavity so as to provide for the exhaust passage portions and for the water jacket cavity, filling the mold cavity with molten metal to provide a unitarily cast engine block, permitting soldification of the block with the cores contained therein, and removing the disposable cores from within the engine block to provide the hollow exhaust passage portions and the water jacket cavity.

Abstract: A hybrid exhaust manifold is provided for use with a vehicular engine. The manifold includes an inlet flange formed from a metal plate to be mounted against the engine cylinder head. The inlet flange includes exhaust ports which align with the exhaust ports of the engine cylinder head. Inner and outer stamped sheet metal shells are provided to mate with one another for forming an enclosed exhaust chamber. The inner shell includes inlet apertures which align respectively with the exhaust ports of the inlet flange. The outer shell includes an outlet aperture. An outlet tube is affixed to the outlet aperture of the outer shell, and an outlet flange is affixed to the end of the outlet tube opposite the outer shell to facilitate connection of the outlet tube to the exhaust pipe. The subject hybrid exhaust manifold can be adapted to fit within a very small space envelope in the engine compartment.

Abstract: An exhaust system for a motorcycle having a V type engine with forwardly and rearwardly facing banks of cylinders. The exhaust system includes relatively short exhaust pipes that are affixed to the rear bank of cylinders and connecting pipes that are detachably connected to these relatively short pipes and which extend to an exhaust device that extends tranversely across the motorcycle and beneath the engine.

Abstract: A double-chambered exhaust manifold with individual chambers that are connected edge to edge so as to independently pass exhaust gas flows through each. The first chamber is connected to receive an exhaust gas flow through exhaust ports of an internal combustion engine and connects to an inlet side of an exhaust driven turbine air compressor. The exhaust gas flow turns a turbine wheel that is connected to an impeller to compress the fresh air flow for passage to the engine air intake system. Exhaust from the turbine then passes to the second chamber that vents the exhaust gases into the vehicle exhaust system. The separate double-chambered exhaust manifolds are bent or otherwise contoured appropriately to fit within the space available within the vehicle engine compartment.