Abstract: Various methods and systems are provided for cooling exhaust system components. In one example, a system comprises heat shield surrounding at least a part of an engine exhaust passage valve positioned in an engine exhaust passage of an engine, and an air jet configured to direct compressed air into the heat shield. The heat shield contains the compressed air around an exterior of the at least the part of the engine exhaust passage valve.

Abstract: A reed valve is adapted to be fixed to a fixing member. The reed valve includes a valve plate and a resiliently deformable reed. The valve plate is fixed to the fixing member and includes a frame part and a supporting column. The frame part has an opening inward of the frame part. The opening passes through the frame part in a thickness direction of the valve plate. The supporting column is disposed across an inside of the opening. The reed is configured to open or close the opening. The frame part includes a frame seating surface with which the reed is engaged. The supporting column includes a column seating surface with which the reed is engaged. The column seating surface is recessed relative to the frame seating surface in the thickness direction.

Abstract: A secondary air system comprising a variable speed air pump and a gated check valve connected between the variable speed air pump and an IC engine. The gated check valve has two ports, and generally, a first of the two ports is connected to a first bank of engine cylinders, and a second of the two ports is connected to a second bank of engine cylinders. The system further comprises a controller for controlling the speed of the variable speed air pump, and the positioning of the gated check valve. The gated check valve is operable to fully close air flow to both ports, fully open air flow to one of the two ports, or variably split air flow between the two ports.

Abstract: A secondary air injection or SAIR system is illustrated and described which includes a first air injection path defined by in part by a lower ditch formed in the head mounting surface of the cylinder block, and a second air injection path defined in part by a second ditch formed in the block mounting surface. The cylinder head gasket is used to separate and seal the first ditch from the second ditch. The first and second air injection paths are separate and isolated from one another such that secondary air may be selectively introduced through the first air injection path into the first exhaust leg and selective introduced through the second injection path into the second exhaust leg independent of the first air injection path.

Abstract: A support system for an exhaust aftertreatment system for a two-stroke locomotive diesel engine providing a secure mounting of certain components of the exhaust aftertreatment system to the locomotive structure while at the same time allowing for differential thermal expansion (and the resulting physical displacement) of the components. The support system further carries the physical mass of the components of the aftertreatment system while at the same time effectively isolating the aftertreatment system from external loads and forces caused by motions of the locomotive engine and the locomotive frame.

Abstract: A method for operating a spark-ignition engine having a three-way catalyst and a particulate filter downstream thereof, comprising: oscillating an exhaust air-fuel ratio entering the particulate filter to generate air-fuel ratio oscillations downstream of the particulate filter, while increasing exhaust temperature; when the downstream oscillations are sufficiently dissipated, enleaning the exhaust air-fuel ratio entering the particulate filter; and reducing the enleanment when an exhaust operating parameter is beyond a threshold amount.

Abstract: A mechanical vacuum pump for an engine includes a flange configured for attachment to a cylinder head of the engine. The flange defines a bore, which is configured for interconnecting an injection air inlet in the cylinder head with an injection air outlet of a secondary air injection valve. The secondary air injection valve is directly mounted to the mechanical vacuum pump, thereby indirectly mounting the secondary air injection valve to the cylinder head of the engine, with the bore communicating fresh air from the secondary air injection valve to the cylinder head.

Abstract: In a charging device for an internal combustion engine, the charging device has at least one first line for the intake of fresh air, having at least one air-gap-insulated exhaust-carrying component. This is assigned to an outlet side of the internal combustion engine. At least one regulating element for distributing an exhaust gas stream, and at least one regulating element for distributing a pre-compressed fresh air stream is provided. The air-gap insulated exhaust-carrying component has an outer chamber, through which a controllable stream of fresh air flows.

Abstract: An engine includes a cylinder, an exhaust port, an exhaust valve, a secondary air supply pipe, and an electromagnetic valve. The electromagnetic valve is opened in a predetermined time period after a point in time when a lift amount of the exhaust valve reaches about half a maximum value during a time period in which an opening of the exhaust port is opened. This causes air to be supplied from a secondary air supply pipe to the exhaust port.

Abstract: An exhaust gas treatment device for a diesel engine is capable of smoothly starting the generation of a combustible gas and is provided with a small combustible gas generator. A core material is fitted in the center portion of an annular wall to form an air-fuel mixing chamber between the inner peripheral surface of the annular wall and the outer peripheral surface of the core material. An air-fuel mixture gas in the air-fuel mixing chamber is adapted to be supplied from the end of the air-fuel mixing chamber to a combustible gas generating catalyst to a portion near the center thereof. A heater is used as the core material, the heat dissipating outer peripheral surface of the heater is exposed to the air-fuel mixing chamber. Heat is dissipated directly from the heat dissipating outer peripheral surface of the heater to the air-fuel mixing chamber when starting the generation of the combustible gas.

Abstract: This invention is to provide a tappet clearance adjusting cover coupled with a secondary air valve. The tappet clearance adjusting cover is disposed on a cylinder head of an engine. The secondary air valve includes a recessed element and a cap which jointly form a receiving space receiving therein a one-way valve. The recessed element is provided with an inlet pipe interposed between the cap and the tappet clearance adjusting cover. By disposing the secondary air valve on the tappet clearance adjusting cover and arranging the inlet pipe between the cap and the tappet clearance adjusting cover, with the one-way valve received in the receiving space of the secondary air valve, heat dissipation can be improved while the one-way valve is protected against premature deterioration and carbon deposition caused by a high-temperature exhaust gas from the cylinder head. Thus, reliability as well as a service life of the one-way valve is effectively increased.

Abstract: A gasket resistant to vibration and noise generation is interposed between a cylinder head and an exhaust manifold of an engine. The gasket includes a gasket main body interposed between a cylinder head and an exhaust manifold of an engine, a base plate affixed to the gasket main body and having a heat shielding portion integral with a base portion and extending to a side of the exhaust manifold, and a reinforcement plate fixed to the heat shielding portion, in which the reinforcement plate is not present at a region of the base portion in contact with the gasket main body, and a reinforcement rib is formed at the region of the base portion in contact with the reinforcement plate and a region of the heat shielding portion in contact with the reinforcement. The base portion is provided with a projected portion projected into a path of introducing secondary air from a side wall of the cylinder head to an exhaust port.

Abstract: A system for reducing ammonia (NH3) emissions includes (a) a first component comprising a first substrate containing a three-way catalyst, wherein the first component is disposed upstream of a second component comprising a second substrate containing an ammonia oxidation catalyst, wherein said ammonia oxidation catalyst comprises a small pore molecular sieve supporting at least one transition metal; and (b) an oxygen-containing gas input disposed between the components. For example, a CHA Framework Type small pore molecular sieve may be used. A method for reducing NH3 emission includes introducing an oxygen-containing gas into a gas stream to produce an oxygenated gas stream; and exposing the oxygenated gas stream to an NH3 oxidation catalyst to selectively oxidize at least a portion of the NH3 to N2.

Abstract: A secondary-air supply system for an internal combustion engine, including a catalyst provided in an exhaust passage and configured to purify exhaust gas from the engine, and a secondary-air supply source and a secondary-air valve provided in a secondary-air passage connected upstream from the catalyst. A secondary-air supply device is configured to drive the secondary-air supply source and to open the secondary-air valve to supply secondary air to the exhaust passage upstream from the catalyst under a warm-up condition of the engine. Secondary-air supply control means is configured to control the secondary-air supply device to drive the secondary-air supply source and to open the secondary-air valve under a high-load operating condition where a flow rate of the exhaust gas is high, the high-load operating condition being different from the warm-up condition.

Abstract: An internal combustion engine includes an exhaust-gas system with n>1 exhaust-gas flow configurations, wherein n is an integer. The exhaust-gas flow configurations are at least partly separated from one another and each of the exhaust-gas flow configurations includes at least one catalytic converter. The internal combustion engine includes a secondary air supply system with at least one secondary air pump and at least one secondary air valve. The at least one secondary air pump is connected, via the at least one secondary air valve, to at most n?1 of the exhaust-gas flow configurations upstream of the at least one catalytic converter of the at most n?1 of the exhaust-gas flow configurations. The remaining ones of the exhaust-gas flow configurations are separated from the secondary air supply system.

Abstract: An exhaust filter system includes a particulate filter (PF) that is disposed downstream from an engine. The PF filters particulates within an exhaust from the engine. A heating element heats particulate matter in the PF. A fastener limits expansion movement of the heating element relative to the PF.

Abstract: The present invention provides an engine including a secondary air supply apparatus for supplying a secondary air to an exhaust gas passage in a cylinder head. The engine comprises a secondary air passage of the secondary air supply apparatus which extends from an outer peripheral surface of the cylinder head through an under-portion of the exhaust gas passage into the exhaust gas passage. The secondary air passage has a groove geometry of passage portion on a matching surface between the cylinder head and a cylinder body.

Abstract: An exhaust system includes a particulate filter (PF) that is disposed downstream from an engine. The PF filters particulates within an exhaust from the engine. A heating element heats particulate matter in the PF. A catalyst substrate or a flow converter is disposed upstream from said heating element. The catalyst substrate oxidizes the exhaust prior to reception by the heating element. The flow converter converts turbulent exhaust flow to laminar exhaust flow prior to reception by the heating element.

Abstract: An exhaust emission control apparatus that is used with an internal combustion engine to use both a NOx retention member and a catalyst while avoiding a decrease in the exhaust gas purification capacity. A NOx occlusion reduction type catalyst is placed in an exhaust path of an internal combustion engine. The NOx occlusion reduction type catalyst includes a base material. The base material includes an exhaust inflow cell, which is closed at its downstream side; and an exhaust outflow cell, which is closed at its upstream side and is adjacent to the first cell with the partition wall positioned in between. The exhaust inflow cell is configured so that a NOx retention layer is formed on the inner surface thereof, and the exhaust outflow cell is configured so that a catalyst layer is formed on the inner surface thereof, respectively.

Abstract: An engine assembly may include a voltage source and an oxygen pump assembly. The oxygen pump assembly may include an intake conduit and an oxygen pumping mechanism. The intake conduit may be in fluid communication with an air supply and an intake manifold. The oxygen pumping mechanism may include an oxygen ion conducting cell, a first electrode in electrical communication with the voltage source and a second electrode in electrical communication with the voltage source. The first electrode may be disposed on a first side of the cell and may be exposed to an interior of the intake conduit. The second electrode may be disposed on a second side of the cell and isolated from the interior of the conduit. The oxygen pumping mechanism may remove oxygen from an air flow within the interior of the intake conduit based on a voltage applied across the cell by the voltage source.

Abstract: A second air flow control apparatus disposed between an air inlet port of an engine and an exhaust port includes a body, a base, a moving member, and a gas thread. The body has a cavity, an air inlet and an air outlet, the air inlet and the air outlet being connected through the cavity. The base is fixed in the cavity, having at least an opening for controlling the air flow through the air flowing path. The moving member is pivotably disposed in the cavity or the base by a spring force and having at least a gate and a cover configured for controlling the area of the opening. The gas thread is connected to the moving member and configured for pulling the moving member to generate a processional rotation and a resetting rotation. The rotations are configured for controlling the gate and the cover part to adjust the opening area of the opening so as to precisely control the second air flow.

Abstract: A secondary air supply system in which individual members may be arranged to be disposed on substantially the same straight line in an engine, whereby connection path lengths are reduced and the attachment thereof is facilitated. The secondary air supply system may be provided between an air cleaner and attached to an engine and an exhaust port of the engine. The secondary air supply system has a secondary air control valve, a lead valve and secondary air supply paths which connect the air cleaner, the secondary air control valve and the lead valve together and supply air to the exhaust port from the air cleaner. The air cleaner, the secondary air control valve and the lead valve may be arranged to be disposed on substantially the same straight line when viewed from the side.

Abstract: An exhaust treatment system and method for removing particulates and/or gases from exhaust gases and for cooling exhaust gases. The exhaust treatment system may include a venturi nozzle for injecting a mixture of water and air into the exhaust gases to cause particulate matter and/or certain gases present in the exhaust gases to adhere to water droplets in the mixture. The exhaust treatment system may further include a receptacle positioned in proximity to the exhaust outlet and adapted for collecting water and particulate matter exiting the exhaust outlet, a filter adapted to receive water from the receptacle and remove particulate matter from the water, and/or a heat transfer device adapted to receive water from the filter and remove heat from the water.

Abstract: A catalytic combustion apparatus is equipped with a reactor for catalytically burning a gas to be treated containing a combustible organic compound, which further comprises a condensate forming means for condensing a part of a gas after reaction in the reactor, to form a condensate, and a pH measuring means for measuring a pH of the resultant condensate. It is preferred that the catalytic combustion apparatus still further comprise a temperature adjusting means for adjusting a temperature of at least a catalyst-packed portion of the reactor based on data measured by the pH measuring means.

Abstract: An air cleaner box structured to facilitate the attaching and detaching operation of an air cleaner element While enhancing the support rigidity thereof. The air cleaner box includes a casing having a case body and the openable and closable case cover. The air cleaner element and the element holder to support the air cleaner element are contained in the casing. The element holder has an extended U-shape in cross section, and has end sections that are supported by the case body and the case cover respectively. The element holder pivots on the bottom face rear ends of the holder lower protrusions in an inclinable manner.

Abstract: Heating device for the heating and gasification of urea or an urea solution, particularly for internal combustion engines, wherein said heating device is designed for installation in a gas line extending in a direction of flow and wherein said heating device has at least two gas-permeable heating surfaces that are spaced apart from each other in the direction of flow and that define a heating chamber. In order to create an improved heating device for stable urea gasification in an exhaust gas line that guarantees a uniform temperature distribution in the heating room as well as a quick response time, according to the invention an inlet opening is provided that discharges into the heating chamber between the at least two heating surfaces and through which the urea or urea solutions can be fed into the heating chamber.

Abstract: A second air flow control apparatus disposed between an air inlet port of an engine and an exhaust port includes a body, a base, a moving member, and a gas thread. The body has a cavity, an air inlet and an air outlet, the air inlet and the air outlet being connected through the cavity. The base is fixed in the cavity, having at least an opening for controlling the air flow through the air flowing path. The moving member is pivotably disposed in the cavity or the base by a spring force and having at least a gate and a cover configured for controlling the area of the opening. The gas thread is connected to the moving member and configured for pulling the moving member to generate a processional rotation and a resetting rotation. The rotations are configured for controlling the gate and the cover part to adjust the opening area of the opening so as to precisely control the second air flow.

Abstract: A pulse detonation wave engine (PDWE) detonation system provides for optical ignition. The detonation system has a plurality of detonation banks, where each detonation bank has a plurality of detonation chambers for receiving a fuel/oxidizer mixture from a propellant source. An optical ignition subsystem generates a plurality of optical pulses. The detonation system also has an optical transport subsystem for transporting the optical pulses from the ignition subsystem to the chambers, where the optical pulses ignite each fuel/oxidizer mixture such that the chambers detonate in a desired order. This allows the banks to be sequentially detonated and the chambers within each bank to be simultaneously detonated, without the increased tankage and toxic ignition associated with conventional approaches.

Abstract: A 4-cycle engine for a motorcycle has a secondary-air supplier for supplying secondary air to exhaust ducts. The engine includes a recess, which is depressed toward the engine, on a cylinder-head cover for holding a control valve of the secondary-air supplier. The recess and the control valve are positioned between two innermost cylinders of the array of the cylinders. Check valves, which are connected to downstream regions of the control valve, are each disposed between two outermost cylinders of the array of the cylinders.

Abstract: In a secondary air supplying structure of an internal combustion engine, extending portions protruding upward are arranged in the number corresponding to the number of cylinders. Extending portions are each provided with a secondary air distribution path. To a surface of extending portion to which secondary air supplying pipe abuts, a seating face that conforms to the outer shape of secondary air supplying pipe is formed. Secondary air distributing path is arranged to be inclined downwardly from secondary air supplying pipe side toward the cylinder exhaust system of cylinder head. Thus, it is possible to provide the secondary air supplying structure of an internal combustion engine that can attain an improvement in the strength of the secondary air supplying path, reduction of the space, rust prevention, reduced costs, reduced weight, simplified structure, and prevention of thermal damage to other components.

Abstract: In a secondary air supply system, each of two branch portions of a secondary air supply pipe that is divided from a joint portion is provided with an air control valve, and the joint portion is provided with a pressure sensor and an auxiliary air control valve. The air control valves are opened at different timings such that pressure fluctuations in the joint portion upon opening of the firstly and the secondly opened air control valves are measured. An abnormality diagnosis is performed with respect to those two air control valves based on combinations of the aforementioned two pressure fluctuations.

Abstract: An intake air filter (1) is for an internal combustion engine, especially in a motor vehicle. The filter has a filter housing (2) having a raw air inlet (4), a pure air outlet (5), and an annular filter element (3) which is arranged in the filter housing (2) and through which air can flow in a radial manner from the outside towards the inside. The filter element has a first end disk (10) on the axial end thereof, said disk has an opening (12) by which means the pure air outlet (5) communicates with the inside (8) of the annular filter element (3). The purpose is to reduce the influence of a secondary air induction on the fresh air supply of the internal combustion engine. To this end, the filter housing (2) has a secondary air outlet (6), on the pure air side, and the annular filter element (3) has a second end disk (11) on an axial end opposing the first end disk (10).

Abstract: A valve assembly defines a chamber and three ports. A first valve selectively obstructs a first port to prevent fluid communication between a secondary air injection pump and the chamber. A second valve selectively obstructs a second port to prevent fluid communication between an air intake manifold and the chamber. A third port provides fluid communication between the chamber and an exhaust manifold. The chamber thus serves as a common passageway for secondary air flowing from the pump to the exhaust manifold and for exhaust gas flowing from the exhaust manifold to the air intake manifold. In a preferred embodiment, the first and second valves are rigidly interconnected.

Abstract: A first heat-resistant filter medium is disposed in an exhaust pathway of an internal combustion engine. The first heat-resistant filter medium traps hydrocarbon compounds and carbon-containing particulates included in a flow of exhaust gas in a dispersive manner to bring the respective particulates and hydrocarbon compounds in contact with oxygen included in the exhaust gas. The trapped hydrocarbon compounds and the trapped carbon-containing particulates are subjected to combustion with the exhaust gas having a filter inflow temperature lower than a combustible temperature of the carbon-containing particulates. A second heat-resistant filter medium is further disposed downstream of the first heat-resistant filter medium to trap the remaining carbon-containing particulates, which have not been trapped by the first heat-resistant filter medium but have passed through the first heat-resistant filter medium. This arrangement desirably enhances the reduction rate of the particulates.

Abstract: A reciprocating piston engine (2) includes an exhaust system comprising an exhaust pipe (8) which communicates with a silencer (10), whose upstream portion (11) is divergent in the direction of gas flow through it, an oxidising catalyst (12) and an air supply pipe (14) communicating with the exhaust pipe at a position upstream of the catalyst and silencer. The air supply pipe (14) includes a Reed valve (16) which is adapted to open under a pressure differential to permit air to flow into the exhaust pipe. In order to maximise the air flow into the exhaust pipe the effect of pressure pulses within the exhaust pipe is utilised and for this purpose 3L2−(2L1+L2) is equal to ±0.25 to 0.

Abstract: The gas-dynamic pressure wave machine is intended for supplying charge air to an internal combustion engine and comprises a rotor (40) with cells (41), a low pressure fresh air inlet channel, a high pressure charge air channel leading to the internal combustion engine, a high pressure exhaust gas channel (31) coming from the internal combustion engine, and a low pressure exhaust gas channel (35), the low pressure exhaust gas channel (35) and the high pressure exhaust gas channel (31) being enclosed in a gas enclosure (34), and the low pressure fresh air inlet channel and the high pressure charge air channel being enclosed in an air enclosure, and the high pressure exhaust gas channel being provided on the rotor side with a widened portion (53).

Abstract: An apparatus and method for reducing pollutants in engine exhaust through the use of pulsed engine compression braking. The apparatus includes a controller, a number of engine sensors connected to the controller, and connections from the controller to the exhaust valves. Bases on data from the engine sensors, the invention opens the exhaust valves during either the compression stroke, the exhaust stroke, or both. Hot fuel mixture or hot gases are then injected into the exhaust manifold, where they burn pollutants. Optionally, pressurized air can be injected into the exhaust manifold to assist in burning pollutants.

Abstract: In a two-stage concept for supercharging of internal combustion engines, in which the first stage is performed by an exhaust-gas turbocharger and the second stage by an electrically driven compressor, the compressor is also used to provide the secondary air used for the heating of a catalytic converter. In this manner, the catalytic converter quickly reaches an efficient operating temperature.

Abstract: An after-treatment system arrangement and method of operating the after-treatment system arrangement is provided for heating the exhaust gas of an internal combustion engine. The after-treatment system arrangement includes an oxidation device for catalytically oxidizing the exhaust gas and a port in the exhaust-gas stream for selectively introducing a controlled amount of oxygen into the exhaust gas in response to a condition of the exhaust gas. The introduction of oxygen can be selectively controlled in response to the temperature of the exhaust gas downstream of the oxidation device. Simultaneously or alternatively, the introduction of oxygen can be selectively controlled in response to the chemical composition of the exhaust gas. The air-to-fuel ratio of the exhaust gas may also be controlled to further facilitate heating of the exhaust gas. The after-treatment system arrangement can also be controlled to remove pollutant emissions from the exhaust gas.

Abstract: Apparatus for supplying supplemental air to exhaust gases exiting exhaust ports in a wall of a cylinder head of a multi-cylinder internal combustion engine and entering runners of an exhaust manifold through runner inlet ports aligned with the respective exhaust ports. An air injection plate is interposed between the cylinder head and the manifold. The air injection plate has openings aligned and registering with the respective exhaust ports and runner inlet ports. A fitting directs the supplemental air to the air injection plate openings to combine with the exhaust gases passing from the exhaust ports to the runner inlet ports.

Abstract: A secondary air supply apparatus controls emissions from an engine through secondary combustion of combustible matters in exhaust gas accomplished by supplying air to an exhaust pipe upstream of an emission control device. A pressure behavior pattern is determined from a pressure value detected by a pressure sensor disposed between an air pump and an open-close valve, and a pressure variation value. The secondary air supply apparatus determines operational states of the air pump and the open-close valve based on variations of the pressure behavior pattern at the time of a secondary air supply control and at the time of a secondary air stop control.

Abstract: An exhaust manifold device is provided to allow air to enter an exhaust manifold during normal operation or an engine to prevent exhaust gases being sucked into the cylinders via exhaust valves. Air can be supplied, via valves (18 and 21) to the exhaust manifold as required and, is supplied to the valve (21) at pressures, above atmospheric pressure, that increase with engine speed. Synchronized electrical pulses are supplied to a solenoid (18A) to open the valve (18).

Abstract: A method of operating a combustion apparatus such as an internal combustion engine (10) is described, in which the apparatus (10) includes at least one combustion chamber (11) with an inlet port (15) for primary combustion air, means (19) to introduce into the combustion chamber (11) primary fuel for combustion with the primary air, an exhaust port (16) for combustion products, and an exhaust system (24) for exhausting the combustion products to atmosphere, the method including introducing into the exhaust system (24) secondary air, mechanically acting upon the secondary air and products of combustion in the exhaust system (24) in the presence of a catalyst, to produce a reformed fuel, introducing the reformed fuel into the combustion chamber (11) for combustion with primary fuel and primary air.

Abstract: An internal combustion engine has a preparation device for fuel, for the purpose of providing a starting fuel which comprises low-boiling fuel constituents. A catalytic converter is accommodated in an exhaust train of the internal combustion engine. After-treatment of the exhaust gases is carried out by a secondary air device, by means of which secondary air is blown into the exhaust train upstream of the catalytic converter, the combustion being carried out with an excess of starting fuel for rich-burn operation during the cold start and the subsequent warm-up phase. The system is provided for spark-ignition mixture-compressing or spark-ignition direct injection internal combustion engines.

Abstract: In a two-stage concept for supercharging of internal combustion engines, in which the first stage is performed by an exhaust-gas turbocharger and the second stage by an electrically driven compressor, the compressor is also used to provide the secondary air used for the heating of a catalytic converter. In this manner, the catalytic converter quickly reaches an efficient operating temperature.

Abstract: A secondary air supply system for an engine of a motorcycle is provided with a secondary air valve composed of integrated reed valve and air-cut valve and the exhaust pipes are connected to exhaust ports formed to the engine. The secondary air valve is arranged at a substantially a central portion on a front side of the engine, below the exhaust ports and in a space between the exhaust pipes and the engine, and secondary air pipes extending from the secondary air valve are connected to secondary air ports formed to an upper portion of the exhaust ports.

Abstract: A secondary air introducing path 23 is formed in a cylinder head 1 along an exhaust port 5. Secondary air is fed by an air pump with pressure, and an outlet 23a of the secondary air introducing path 23 is formed so that a blowing direction of the outlet 23a is directed to an exhaust valve 7 side. There is provided a water jacket 22 between the secondary air introducing port 23 and an upper portion of the cylinder head 1.

Abstract: An internal-combustion engine includes an engine control system that permits a change-over between a lean operation and a rich operation of the internal-combustion engine, and an exhaust gas purification system. A &lgr;-probe, an SOx storage catalyst and an NOx storage catalyst are successively arranged in an exhaust gas line behind the engine. At the start of desulfurization of the SOx storage catalyst, a change-over takes place from the lean to the rich operation of the engine. Secondary air is fed into the exhaust gas line; a predetermined &lgr; value of the exhaust gases mixed with secondary air and a temperature in the SOx storage catalyst are measured. At the end of the desulfurization, a change-over takes place from the rich to a lean operation of the engine.

Abstract: To provide an apparatus for feeding secondary air to exhaust gas in an engine. The apparatus includes a cylinder head having an exhaust port for discharging exhaust gas from a combustion chamber and a secondary air feed passage for feeding secondary air to exhaust gas flowing through the exhaust port. The apparatus is capable of making a length of the secondary air feed passage as short as possible while preventing the permeation of exhaust gas into the secondary air feed passage. This avoids the enlargement of the entire engine, when disposing a reed valve in the engine, since the reed valve is mounted to the cylinder block. A secondary air passage includes a first passage portion extending in a straight line with one end opened toward the inner surface of an exhaust port, toward the downstream side of exhaust gas in the flowing direction.

Abstract: An air cleaning system for an engine includes a main air cleaner for supplying cleaned air to an intake system of the engine and a sub-air cleaner for supplying cleaned air to an exhaust system of the engine. The main air cleaner includes a main air cleaner housing divided into a dirty air chamber and a clean air chamber by a first air cleaning element. The sub-air cleaner is disposed in the dirty air chamber, and has its own second air cleaning element, physically separated from the first air cleaning element.