Abstract: The method of combusting fuel containing exhaust gas comprising the steps of:a. obtaining a gaseous admixture of air and said exhaust gas, said admixture having an adiabatic flame temperature below about 1400.degree. temperature;b. contacting at least a portion of said admixture with a catalytic surface and producing reaction products; andc. passing said reaction products to a thermal reaction chamber;thereby igniting and stabilizing combustion in said thermal reaction chamber at a temperature below 1400.degree. Kelvin.

Abstract: A catalyst is integrated into a cylinder block of an engine and positioned near at least one exhaust port thereof. A separation wall is provided for dividing the exhaust flow into two branches, one of which contains the catalyst. A control device responsive to at least one engine parameter selectively seals one of the branches such that exhaust is either passed through the catalyst or around the catalyst. A coolant passage is provided adjacent the catalyst to prevent overheating.

Abstract: Disclosed herein is a marine propulsion device comprising a combustion chamber, an exhaust passage, an air pump and a three-way catalytic converter. The air pump pumps air into the exhaust passage at or immediately upstream of the catalytic converter. By this construction the internal combustion engine can be run slightly rich, but the catalytic converter will see a close to stoichiometric mixture so that the pollutants in the exhaust stream can be oxidized or reduced appropriately since the catalytic converter will be able to operate as a three-way catalytic converter.

Abstract: A catalyzer arrangement for the exhaust gases of an internal combustion engine in which the catalyzer body (6, 7) is formed from a weave, knit or fabric of metal fibers, metal chips, metal wires, metal powder or a mixture of them which is pressed together in several layers (11) to form a pack in the outlet region (4) of the cylinder of the internal combustion engine in front of the exhaust gas manifold (5) and/or in the inlet region of the exhaust gas manifold (5). In addition, or as an alternative, the cylinder crown (8) in the cylinder (2) of the internal combustion engine can also be provided with a catalyzer body (9).

Abstract: An exhaust purifying device applicable to an exhaust system extending from an internal combustion engine has a casing and a core received in the casing. The core has a honeycomb structure implemented by a corrugated sheet metal and a flat sheet metal rolled up together in a spiral configuration. Part of the flat sheet forming the outer periphery of the core is formed with a plurality of openings. The core is locally affixed to the casing by a solder applied to the portions of the flat sheet surrounding the openings and opposite edges of the flat sheet. This is successful in surely and stably affixing the core to the casing despite that the solder is implemented as an inexpensive powdery solder.

Abstract: An exhaust silener for a compact 2-stroke cycle internal combustion engine has a housing, a sheet of sound absorbing material provided on the inner surface of the housing, and an oxidation catalyst means provided on the surface of the sound absorbing material. The catalyst serves to promote oxidation of unburnt components of lubricating oil in exhaust gases.

Abstract: A manifold converter comprises a housing constructed of two metal shells welded at their mating edges; a catalyzer carrier unit installed in the housing in a manner to define therein upstream and downstream portions with respect to the catalyzer carrier unit; and a sealing mat disposed between the catalyzer carrier unit and the housing to achieve a hermetical sealing therebetween. A binding structure is further employed for binding a given portion of the housing where the sealing mat is located. With this binding structure, undesired permanent expansion of the housing caused by the inevitable thermal expansion is suppressed or at least minimized.

Abstract: Disclosed herein is an outboard motor comprising a drive shaft housing including an inner wall partially defining a pumping chamber, an air inlet port communicating between the pumping chamber and the atmosphere, and an air outlet port communicating with the pumping chamber, a propeller shaft rotatably supported by the drive shaft housing, an engine mounted on the drive shaft housing, a drive shaft drivingly connecting the engine to the propeller shaft, a closure member which is supported by the drive shaft housing, which partially defines the pumping chamber, and which rotatably supports the drive shaft, an exhaust passageway communicating with the engine, a catalytic converter located in the exhaust passageway and communicating with the outlet port, and an impeller located in the pumping chamber, mounted on the drive shaft for rotation therewith, and operative to supply air to the catalytic converter.

Abstract: An internal combustion engine assembly comprising an internal combustion engine including an exhaust port, an exhaust conduit communicating with the exhaust port and having an inner surface, the conduit including first and second conduit portions having respective ends, the first and second conduit portions being connected end-to-end, a catalyst which is located within the conduit and which includes catalytic material and a sleeve surrounding the catalytic material, the sleeve having a length and an outer surface spaced from the inner surface of the conduit along substantially the entire length of the sleeve, the sleeve having thereon a rigid, radially outwardly extending flange captured between the ends of the conduit portions, and a flexible gasket between the flange and the end of one of the conduit portions.

Abstract: A layout structure of catalytic converters, used for an engine transversely arranged in an engine room formed in a front portion of a vehicle, includes a front catalytic converter connected to an exhaust manifold arranged in a forward direction of the vehicle with respect to the engine, and a rear catalytic converter connected to an exhaust manifold arranged in a backward direction of said vehicle, wherein the rear catalytic converter is arranged to be offset from a central position of the engine arranged along a widthwise direction of the vehicle by a predetermined distance. With this structure, the rear catalytic converter can be cooled in the same manner as the front catalytic converter. In addition, the rear catalytic converter is formed into a cylindrical member having an elliptic/oval cross-sectional shape with a major axis coinciding with a longitudinal direction of the vehicle, thus increasing the area of a heat-dissipating surface of the rear catalytic converter.

Abstract: An exhaust manifold catalytic reactor and muffler for an automotive internal combustion engine includes at least one exhaust branch for conducting exhaust gases from the cylinder head exhaust ports of an engine to a hollow, generally cylindrical primary catalyst substrate for treating the exhaust gases flowing from the engine. The substrate has inner and outer surfaces which are generally cylindrical and which define an inner cavity. A housing connected to the exhaust branch places the exhaust gases in contact with the substrate and includes a generally cylindrical container having an outer wall and a transition section conducting the exhaust gases from the branch to the outer surface of the substrate such that the initial flow of the gases from the branch to the outer surface of the substrate such that the initial flow of the gases from the substrate is generally tangential.

Abstract: The exhaust gas purification system for an engine with two banks provides a pair of bypasses for interchangeably communicating with each of the exhaust pipes from the two banks. A changeover valve is inserted at the junction point of the bypass and is inserted at the junction point of the bypass and the exhaust pipe for changing the flow of the exhaust gas. When the catalyst temperature is lower than a predetermined value, the exhaust gas flows directly into the catalyst. When the catalyst temperature is higher than the predetermined value, the exhaust gas flows into the bypasses for cooling the exhaust gas and then into the other side catalyst. Therefore, the activity performance of said catalyst is improved in both cold and hot states.

Abstract: This invention relates to a emission control device containing a catalytic material capable of reducing pollutants in the combustion gases generated from an internal combustion engine, as well as from other combusted solid and liquid fossil fuels such as coal, and is also useful for treating combustion gases generated from the incineration of landfill garbage and tire rubber, among others. The catalytic material of the present invention is highly resistant to deactivation or poisoning from contaminants in the combusted material such as leaded gasoline. The catalytic material predominantly comprises a plagioclase feldspar belonging mainly to the albite-anorthite series and contains small amounts of mica, kaolinite and serpentine, and optionally contains magnetite.

Abstract: Disclosed herein is an outboard motor comprising an engine block assembly including a lower surface having therein first and second exhaust gas openings, upper and lower cylinders having respective axes parallel to the lower surface and including respective exhaust ports, an exhaust gas collector passage communicating with the exhaust ports, an exhaust gas pulse passage extending between the collector passage and the first exhaust gas opening, and an exhaust gas discharge passage extending between the collector passage and the second exhaust gas opening and including therein a catalytic element, a drive shaft housing fixed to the lower surface of the engine block and including a discharge gas duct terminating in an underwater discharge opening, and an exhaust gas housing located in the drive shaft housing and including an upper end fixed to the lower surface of the engine block, a lower end, an exhaust gas pulse passageway communicating, at the upper end thereof, with the first exhaust gas opening and being c

Abstract: An apparatus for purifying air which may act downstream supplement to a catalytic converter of an internal combustion engine for further reducing the hydrocarbon and carbon monoxide gases which the catalytic converter failed to remove. The apparatus comprises a housing filled with volcanic ash over which is directed a turbulent stream of exhaust gases for chemical reaction with the volcanic ash.

Abstract: An exhaust system for a motorcycle that includes an exhaust sensor that extends into the exhaust system at a low point in the motorcycle. A plurality of baffles are positioned around the exhaust sensor so as to protect its extending portion from damage from foreign objects.

Abstract: An integral manifold-muffler-catalyst device (for an internal combustion engine having a plurality of combustion cylinders generating exhaust gases), comprising: (a) a monolithic catalyst having a plurality of aligned passages for effecting laminar flow of the exhaust gases therethrough while; (b) a high temperature resistant chamber assembly for close-coupling the catalyst to the engine having (i) an expansion chamber for substantially dissipating low frequency standing sound waves of said exhaust gases and for modifying high frequency sound waves of said exhaust gases and (ii) manifolding passages at one side of the expansion chamber for collecting and delivering the exhaust gases from the cylinders to the expansion chamber; and (c) means for effecting converging flow from said expansion chamber to and across substantially the full entrance face of said aligned passages, as well as from the catalyst, for effecting attenuation of high frequency sound waves carried by the exhaust gases.

Abstract: A number of embodiments of outboard motors having catalytic exhaust systems. In each embodiment, an expansion chamber is formed in the drive shaft housing and the exhaust gases are delivered to the expansion chamber from an exhaust pipe that extends at least in part through the expansion chamber and which terminates at its lower end in the lower portion of the expansion chamber. A catalyst bed is positioned at the upper end of the expansion chamber and beneath the engine and through which the exhaust gases must pass for discharge through a further exhaust conduit which extends at least in part through the expansion chamber and which terminates at an underwater exhaust gas discharge.

Abstract: A catalytic converter is mounted at the exhaust gas outlet of a muffler for a two or four-cycle internal combustion engine of the type having one or two cylinders such as those used for lawn and garden equipment. The catalytic converter is located exteriorly of the muffler body in the path of the exhaust gases for oxidizing and/or reducing exhaust gas components subsequent to their discharge from the muffler. Secondary air supply is provided upstream of the catalyst within the converter by mounting the catalytic converter to provide a gap between the converter and the muffler body. Alternately, secondary air is provided by at least one opening formed in the converter upstream of the catalyst which communicates between the interior of the converter and atmosphere.

Abstract: The exhaust gases of a two-bank internal-combustion engine are guided, by way of exhaust gas collectors, to a central expansion chamber of a housing. From there, they flow through main catalysts arranged on opposite ends of the housing, before they are guided into the open air by way of end mufflers.This exhaust system provides a space-saving arrangement of all components required for an optimal emission control, and low exhaust gas back pressure, and meets all acoustic requirements.

Abstract: Several embodiments of external low speed exhaust gas discharge treatment devices for outboard motors that may be attached to the outer housing of the outboard motor to provide silencing for the exhaust gases without necessitating complicated driveshaft housing constructions.

Abstract: An exhaust manifold muffler having an exhaust manifold portion 10 and a muffler portion 20 integral with the exhaust manifold portion 10. The exhaust manifold portion 10 includes a plurality of manifold pipes 11 having parallel downstream ends which are spaced from each other and are arranged in a row. Each manifold pipe is connected to a respective cylinder of an internal combustion engine such that exhaust presssure pulsations from the manifold pipes operate as reflected waves opposite in phase, so as to damp the pressure pulsations. The muffler portion 20 has a first muffler chamber 22 and a swirl pipe 29 installed in the first muffler chamber 22. The manifold pipes 11 extend tangentially into the first manifold chamber to produce a swirl in the first muffler chamber 22. Part of the swirl enters an upper inlet end of the swirl pipe. The swirl pipe 29 has a lower outlet end which is located between the downstream ends of the manifold pipes 11.

Abstract: An exhaust gas purifying arrangement is provided for an outboard motor for a watercraft. At least one exhaust port is provided which opens into a first exhaust passage having a first catalyst member lining at least a portion of its inner wall. The first exhaust passage then opens into an exhaust expansion chamber. Next, a second exhaust passage originates just beyond the expansion chamber. A second catalyst member is mounted within and across a section of exhaust passage beyond the first exhaust passage and at a location above the water line within which the outboard motor operates. A first passageway is provided which leads from the second exhaust passage, from a position beyond the second catalyst member, to an exhaust outlet located at a position below a body of water in which the watercraft operates.

Abstract: In an exhaust system for an internal combustion engine having a main exhaust conduit with a catalytic converter arranged remote from the engine and a bypass exhaust conduit which includes a start-up catalytic converter arranged close to the engine and joins the main exhaust gas conduit ahead of said remote catalytic converter, an ejector structure is arranged in the main exhaust gas conduit within a housing defining a suction chamber in communication with the bypass exhaust conduit for drawing gas through the bypass exhaust conduit into said main exhaust gas conduit whenever exhaust gas flows from the engine through the main exhaust gas conduit and a main exhaust conduit valve is arranged between the ejector structure and the junction of the main and the bypass exhaust conduits which is closed during start-up operation of the engine to thereby force the exhaust gas to flow through the suction chamber and the bypass exhaust gas conduit via the start-up catalytic converter.

Abstract: An improved exhaust treatment apparatus includes a particulate filter assembly connected to the exhaust system of a diesel engine for removing the solid particulate soot matter entrained in the engine exhaust. The particulate filter assembly includes a disposable low-temperature filter element that can be readily replaced when it becomes clogged. Heat insulated catalyst assemblies located upstream of the particulate filter assembly reduce the amounts of solid particulate matter and other gaseous pollutants in the engine exhaust. A self-cleaning exhaust gas heat exchanger located between the catalyst assemblies and the particulate filter cools the hot, catalyzed exhaust gases before they reach the low temperature filter element. The self-cleaning heat exchanger also includes an intermittent water injection system for periodically removing soot accumulations from the heat exchanger.

Abstract: A motorcycle having an exhaust system with a sensor in the exhaust system for engine control. The sensor is located so that it will be protected by the exhaust device into which it protrudes and by other portions of the motorcycle. The exhaust system includes a plurality of exhaust pipes and the exhaust device and one of these exhaust pipes is readily removable from a unitary assembly comprised of the remaining exhaust pipes and exhaust device so that an adjacent component of the motorcycle can be easily serviced.

Abstract: The exhaust gases of both cylinder banks of a multi-cylinder reciprocating engine first flow through a catalyst situated along the respective cylinder bank and then, in a cross countercurrent, flow through a horizontally situated muffler arranged transversely to the cylinder banks.

Abstract: In the typical embodiment described in the specification, the exhaust system of an internal combustion engine has two exhaust lines with corresponding catalyst assemblies, each assigned to one group of combustion chambers. During the cold start of the engine, an electric heater included in one of the exhaust lines heats exhaust gases flowing to a first catalyst assembly and the catalyst assemblies are connected in series so that the exhaust gases supplied to the second catalyst assembly are received from the first catalyst assembly. In addition, the ignition point of the engine is retarded after idling speed is reached. To avoid overheating of the catalyst assemblies, the catalyst assemblies receive exhaust gases only after their start-up temperatures are reached from the groups of combustion chambers associated with them and an exhaust cooling line is provided to cool exhaust gases flowing to the first catalyst assembly.

Abstract: The present invention provides an improved exhaust emission control arrangement for an outboard motor. A catalyst material holding structure is mounted within an exhaust passage of an engine. A thermally insulating interstice is located between an inner wall of the exhaust passage and the outer periphery of the catalyst material holding structure, so that the interstice physically separates the catalyst material holding structure from the inner wall of the exhaust passage. The interstice prevents significant heat transfer between the catalyst material reaction sites at which exhaust gas cleansing takes place and engine components which are positioned proximate thereto. The invention permits the effective cleansing of exhaust gases under all engine operating conditions.

Abstract: An exhaust system for an engine having two groups of cylinders includes a small capacity catalytic converter disposed in an exhaust manifold for one group of cylinders and a larger capacity catalytic converter disposed in an exhaust manifold for another group of cylinders. The exhaust system also includes a primary catalytic converter, having a capacity larger than both the small and larger catalytic converters, disposed in an exhaust pipe commonly connected to the exhaust manifolds.

Abstract: An integral manifold-muffler-catalyst device (for an internal combustion engine having a plurality of combustion cylinders generating exhaust gases), comprising: (a) a monolithic catalyst having a plurality of aligned passages for effecting laminar flow of the exhaust gases therethrough while; (b) a high temperature resistant chamber assembly for close-coupling the catalyst to the engine having (i) an expansion chamber for substantially dissipating low frequency standing sound waves of said exhaust gases and for modifying high frequency sound waves of said exhaust gases and (ii) manifolding passages at one side of the expansion chamber for collecting and delivering the exhaust gases from the cylinders to the expansion chamber; and (c) means for effecting converging flow from said expansion chamber to and across substantially the full entrance face of said aligned passages, as well as from the catalyst, for effecting attenuation of high frequency sound waves carried by the exhaust gases.

Abstract: An exhaust gas cleaning system is provided for use with a watercraft engine. A plurality of horizontally positioned exhaust ports are located within an engine cylinder head. An exhaust manifold communicates with each of the exhaust ports at a first end and forms a gas collecting pipe at its second end. The second end of the gas collecting pipe is positioned above the exhaust ports. A generally horizontally positioned exhaust pipe extends from the second end of the gas collecting pipe and continues in a rearward direction. Means are provided for introducing coolant from the engine into the rearwardly extending portion of the exhaust pipe. A removable catalyst member is located within and across the exhaust pipe between the exhaust manifold and the area where coolant is introduced into the exhaust pipe. The catalyst is provided with a plurality of small holes therein, so that exhaust gases may be effectively cleaned.

Abstract: A large diesel engine is provided with a manifold arrangement in which a catalytically coated static mixer is disposed within an exhaust manifold. In addition, nozzles are provided in an annular chamber between the static mixer and the exhaust manifold in order to introduce a reducing agent into the flow of exhaust gas prior to entry into the static mixer. Alternatively, the reducing agent can be injected via a nozzle centrally located in a cover at the end of the manifold.

Abstract: A marine propulsion device comprising a drive shaft housing, a propeller shaft rotatably supported by the drive shaft housing, an internal combustion engine drivingly connected to the propeller shaft, the engine including a cylinder block defining a cylinder having an exhaust port, and defining an exhaust outlet, and an exhaust passage between the exhaust port and the exhaust outlet, an exhaust catalyst apparatus mounted on the cylinder block, the apparatus including a tongue extending into the cylinder block exhaust passage and dividing the cylinder block exhaust passage into an upstream portion communicating with the exhaust port and a downstream portion communicating with the exhaust outlet, and the apparatus including an exhaust passage communicating between the upstream portion and the downstream portion, and a catalyst located in the apparatus exhaust passage.

Abstract: An exhaust gas purifying arrangement is provided for an outboard motor for a watercraft. At least one exhaust port is provided which opens into a first exhaust passage having a first catalyst member lining at least a portion of its inner wall. The first exhaust passage then opens into an exhaust expansion chamber. Next, a second exhaust passage originates just beyond the expansion chamber. A second catalyst member is mounted within and across a section of exhaust passage beyond the first exhaust passage and at a location above the water line within which the outboard motor operates. A first passageway is provided which leads from the second exhaust passage, from a position beyond the second catalyst member, to an exhaust outlet located at a position below a body of water in which the watercraft operates.

Abstract: An exhaust gas cleaning device is disposed within an exhaust pipe connected to the exhaust port of an internal combustion engine. The exhaust gas cleaning device comprises an inner pipe disposed coaxially within the exhaust pipe with an annular space defined therebetween, the inner pipe being provided with a plurality of perforations, and laminated structures disposed upon the inner and outer surfaces of the inner pipe and including a catalyst for cleaning unburned components of the exhaust gas flowing within the exhaust pipe, each of the laminated structures being formed of a material which is not deleterious to the catalyst. The laminated structure includes a catalyst carrier layer formed by, in accordance with one method, fusibly injecting a catalyst including a solution onto an intermediate layer formed upon the inner and outer surfaces of the inner pipe and drying the same so as to remove the liquid component therefrom.

Abstract: An exhaust system for a v-configured, internal combustion engine having a close-coupled, catalytic converter having a converter assembly located adjacent the engine comprising a pre-chamber upstream of the catalyst support which has inlet assemblies oriented, and a cross-section configured to induce a centrifugal swirling action in the exhaust gas as it passes therethrough. The swirling action of the exhaust gas inhibits reversion of particles, trapped upstream of the converter, into the engine.

Abstract: A motor vehicle having a transversely positioned engine in a forwardly disposed engine compartment. The exhaust manifold is formed rearwardly of the engine and supplies exhaust gases to a catalyzer so that the engine will shield the exhaust manifold and catalyzer from cooling air flow. An intake manifold extends forwardly from the engine and engine accessories are disposed beneath the intake manifold and forwardly of the cylinders of the engine so as to shield the occupants of the vehicle from the noise of the accessories. In addition, a crushable plenum chamber extends across the front of the intake manifold and forwardly of the accessories for silencing and also to absorb impacts. The crushability of the plenum chamber causes it to slow the engine on impact for further safety protection.

Abstract: A catalyst according to the invention with its cooling package is an easily exchangeable unit that is plugged into an existing silencing device. The catalyst (29) is integrated with a perforated radiation protection and distribution plate (26) in front of it and furthermore with another plate behind it functioning as a lid (24) and fastening member against a silencer. Outside the lid there is a cooler attached which removes the heat. A waste gas outlet (32) takes place via a waste gas tube (23) to the rear corner of the silencer, where fan air, used for engine cooling, passes by. The waste gases get mixed to the fan air and the temperature will be reduced to an acceptable level.

Abstract: There is provided a new and useful combined muffler and catalytic converter exhaust unit for the exhaust stream from an internal combustion engine, the combined unit comprising a housing having an inlet and an outlet, first and second chambers within the housing, an oxidation/reduction catalyst within the first chamber, noise muffling means within the second chamber, and wherein the first chamber has an inlet leading to the inlet of the housing and an outlet leading to an inlet of the second chamber, and the second chamber has an outlet leading to the outlet of the housing.

Abstract: The invention relates to a thermally, and optionally catalytically, operative exhaust gas treatment reactor of an engine, comprising filamentary material directly against and inside the heat insulating portion of a housing assembly which is placed on an engine over the exhaust ports, either directly or with a member interposed. Rapid warm up during cold start is achieved by restriction of gas flow, with the optional re-routing of exhaust gas, including routing to a reservoir which may be expansible. Other features include various embodiments of filamentary material, mechanism for accurately regulating exhaust gas recirculation and provision of extra air, the providing a secondary substance such as water/methanol or steam to induction charge to assist in the balancing of exhaust reactions. Treatment of exhaust gas is generally but not specifically to remove certain undesired pollutants from the exhaust gas of vehicles as required in many countries.

Abstract: In an exhaust system, particularly for two-stroke cycle internal combustion engines, at least that portion which adjoins the internal combustion engine consists of two joined shell sections made of sheet metal and contains a catalytic converter. In order to simplify the manufacture and to ensure that the gas dynamics will not adversely be affected, the catalytic converter is constituted by a central partition, which extends between the sheet metal shell sections in the direction of flow of the exhaust gases and is provided with a catalytic coating and is optionally apertured.

Abstract: A two-stroke spark ignited engine (10) with direct fuel injection (14) and an exhaust gas treatment catalyst. A separate catalyst unit (23) is provided for each combustion chamber (11) and is located at or adjacent each exhaust port (15) from that chamber and that during a cycle of each combustion chamber (11) the catalyst unit (23) of that combustion chamber (11) is exposed only to exhaust gases which change from chemically reducing to chemically oxidizing during the cycle. An engine which has exhaust gases which are overall chemically oxidizing can thus nevertheless have the NOx constituents of the gases reduced.

Abstract: A catalytic exhaust system for a marine outboard drive wherein the catalyzer material is supported by a heat conductive bracket and the bracket is cooled by a cooling jacket that is supplied with coolant from the engine cooling jacket. In one embodiment, the water jacket is cooled both internally and externally by delivering water from the cooling jacket into the exhaust system to impinge upon a wall of the cooling jacket.

Abstract: A first filter is disposed in an engine exhaust passage. A second filter is disposed in the engine exhaust passage at a location downstream of the first filter. Thus, the first and second filters are connected in series with one another. The first and second filters are designed so that an amount of exhaust particles trapped by the first filter is greater than an amount of exhaust particles trapped by the second filter. A pressure across the series combination of the filters may be detected. The filters may be rejuvenated when the detected pressure across the series combination of the filters reaches a reference pressure.

Abstract: A catalytic converter including within the housing a pellet enclosure which is of resilient screen, the enclosure compressing the body of pellets such that the pellets are held firmly in place under tension. The screen enclosure is compressed by the housing to increase tension on the body of pellets. In preferred embodiments the screen enclosure and body of pellets are tubular, with one edge compressed inwardly by a tubular housing. The screen enclosure and body of pellets are preferably tapered.

Abstract: The invention relates to an exhaust gas muffler for a two-stroke engine of a portable handheld tool such as a chain saw. The exhaust gas muffler includes a catalyzer wherein high exhaust gas temperatures are developed because of the exothermal reaction which takes place therein. The catalyzer is located in the forward portion of a gas-tight hollow body mounted in the housing of the muffler. The hollow body has a tapered portion which extends out of the housing in the direction of the exhaust gas flow. In this way, the surface temperature of the muffler housing is reduced.

Abstract: An outboard motor having an improved catalyst system for treating the exhaust gases regardless of whether they are delivered to the atmosphere through an above the water exhaust gas discharge or a below the water exhaust gas discharge. When the engine is operating at high speeds, the exhaust gases only have surface contact with the catalyzer bed and do not flow through it while under slow speeds the exhaust gases flow through the catalyzer bed.

Abstract: A number of embodiments of treating the exhaust gases of an internal combustion engine with a catalyzer so as to render lubricant in the exhaust gases in a non-polluting form. A number of embodiments applying this principle to marine propulsion units are illustrated and described which include outboard motors and inboards. In each embodiment, the catalyst is position so that the exhaust gases will impinge upon it but need not flow through it for their discharge to the atmosphere. In addition, the exhaust system is designed in such a way that the catalyst may be removed and replaced simply by the use of a removable wall section of the exhaust system.

Abstract: A process for the regeneration of engine emission particulates collected in particulate filter traps associated with each of the engine cylinders, or with groups of such cylinders, includes the selective elevation of the emission temperature of at least one of the cylinders or groups to the extent required for regeneration, by oxidation, of the filter trap or traps associated therewith, by supplying engine fuel to such cylinder or cylinders in a predtermined amount to produce the elevated emission temperature, and supplying the remaining of the cylinders with amounts of engine fuel less than such predetermined amount as required to sustain the given engine power output.