Abstract: An adapter for retrofitting to a stock engine for use in performance racing. The adapter is fitted between a stock air filter and a stock throttle or carburetor and provides a safe and secure mounting point for nitrous oxide/fuel injection nozzles or spray bars. Two embodiments are disclosed: the first for use directly between the air filter and the throttle body or carburetor and the second for installation using standard air hoses.

Abstract: A method and system for the intake air separation within an internal combustion engine is disclosed. The disclosed embodiments of the intake air separation system include an intake air inlet adapted to receive substantially all of the intake air used in the combustion process for the engine and an intake air separation device in flow communication with the intake air inlet and adapted for separating substantially all of the intake air into a flow of the oxygen enriched air and a flow of nitrogen enriched air. The intake air separation system further includes a first outlet in fluid communication with the intake air separation device and adapted to receive a flow of the oxygen enriched air as well as a second outlet also in fluid communication with the intake air separation device and adapted to provide the flow of nitrogen enriched air to the intake manifold for use in the combustion process.

Abstract: An invention relates to an intake device for an internal combustion engine, to which at least combustion air and an additional fluid can be supplied via an air inlet line (1). The air inlet line (1) has an opening, in particular a hole (9), through which a guide tube (11) projects into the air inlet line (1).

Abstract: An air induction system is arranged to introduce air into a plurality of combustion chambers. The air induction system includes intake passages through which the air flows to the combustion chambers. Throttle valves are arranged to regulate an amount of the air flowing through the intake passages. Auxiliary runners communicate with the intake passages at a location positioned downstream of the throttle valves. The respective runners are unified with each other to form a common chamber. A single conduit has an end communicating with the common chamber and another end communicating with a location that generally is at atmospheric pressure. The air flowing through the conduit, the common chamber and the auxiliary runners also is supplied to the combustion chambers. The common chamber can be positioned next to the intake passages. A control valve can be provided at a location along the single conduit.

Abstract: A compact and efficient rotary pressure swing adsorption (PSA) apparatus with laminated sheet adsorbers is used to supply enriched oxygen and/or nitrogen streams to an internal combustion engine, allowing for reduced noxious emissions and enhanced engine performance.

Abstract: An engine includes an engine body and an air induction system. The engine body includes a cylinder block defining a cylinder bore in which a piston reciprocates. A cylinder head member closes an end of the cylinder bore to define a combustion chamber together with the cylinder bore and the piston. The air induction system is arranged to introduce air into the combustion chamber. The induction system includes a first intake conduit through which the air flows to the combustion chamber. A first plenum chamber unit is disposed upstream of the first intake conduit. A control mechanism is arranged to control an amount of the air flowing through the first intake conduit. The induction system also includes a second intake conduit through which the air flows to the combustion chamber. A second plenum chamber unit is disposed upstream of the second intake conduit. The second intake conduit is coupled with the first intake conduit downstream of the control mechanism.

Abstract: A bypass passage includes an inlet in communication with the upstream sides of first and second throttle valves of first and second suction passages. One valve body receiving chamber is coaxial with the inlet. First and second upstream side branch passages extend from the valve body receiving chamber. Downstream side branch passages extend from the end portions of the upstream side branch passages and are in communication with the downstream sides of the first and second throttle valves of the first and second suction passages. One bypass valve is movably received in the valve body receiving chamber and can open the first and second upstream side branch passages to be at the same opening. Reducing the number of bypass valves to one can reduce the manufacturing costs and the number of man hours for assembly of the throttle unit and can equalize the rate of air flowing through the respective bypass passages.

Abstract: The present invention provides a fuel injection device comprising an intake pipe having interior wall surfaces for providing air from an upstream side to a downstream side and a fuel injection port disposed in the intake pipe between the surfaces for providing fuel into the intake pipe and an air guide member disposed in the intake pipe in a plane substantially parallel to the surfaces for guiding air separately towards an air flow layer passage and a main air passage wherein the air guided towards the air flow layer passage has a speed at least greater than the air guided towards the main air passage.

Abstract: A fuel system for an internal combustion engine has an air-assist fuel injection system. An oxygen generator is employed to supply oxygen-enriched air to the fuel injector to create a more readily ignitable mixture in the engine combustion chamber.

Abstract: Atomized particles within a desired size range (e.g., 1 micron to about 5 microns) are produced from two immiscible fluids, the first a fuel source containing the formulation to be atomized, and a second fluid source which is contained in a pressure chamber surrounding at least the area where the first liquid is to be provided. The invention provides a method for the formation of small, relatively uniform fuel particles for use in internal combustion engines and a nozzle-type apparatus for providing the particles to a combustion chamber.

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: Anoxidizer and fuel plate is disclosed which discharges nitrous oxide and fuel into an intake manifold.The plated between a carburetor and an intake manifold and it provides a construction which slow the flow of the nitrous oxide so that the nitrous oxide introduced into the airstream is substantially uniformly distributed.

Abstract: An apparatus for enriching oxygen in the combustion air of internal-combustion engines has a gas centrifuge (1) which is driven by an exhaust gas turbine (2) in the exhaust pipe (4)

Abstract: A bypass passage includes an inlet in communication with the upstream sides of first and second throttle valves of first and second suction passages. One valve body receiving chamber is coaxial with the inlet. First and second upstream side branch passages extend from the valve body receiving chamber. Downstream side branch passages extend from the end portions of the upstream side branch passages and are in communication with the downstream sides of the first and second throttle valves of the first and second suction passages. One bypass valve is movably received in the valve body receiving chamber and can open the first and second upstream side branch passages to be at the same opening. Reducing the number of bypass valves to one can reduce the manufacturing costs and the number of man hours for assembly of the throttle unit and can equalize the rate of air flowing through the respective bypass passages.

Abstract: A method and apparatus for reducing oxides of nitrogen in the exhaust of an internal combustion engine. The apparatus includes a pressurizing unit for providing compressed air to a pressure swing adsorption unit. The pressure swing adsorption removes nitrogen from the air to produce nitrogen-reduced air, which is then supplied to the engine. The pressurizing unit may be a compressor, a turbocharger, or a supercharger. The engine may utilize exhaust gas recirculation and fuel injection with air assist.

Abstract: An improved injection valve apparatus for variably controlling the injection of nitrous oxide and supplemental fuel into a combustion engine, and method for controlling and varying the amounts of nitrous oxide and supplemental fuel injected into a combustion engine based on existing engine conditions. The method programs engine parameters for the timing and volume of nitrous oxide injected into an engine, continuously monitors engine performance and engine conditions, and adjusts the amount of nitrous oxide injected and additional fuel supplied in response to changing engine conditions.

Abstract: A fuel injector for use in a internal combustion engine is disclosed. The fuel injector includes a body having a discharge end and a longitudinal axis extending therethrough, and an electromagnetic coil located within the body. The fuel injector further includes a fuel metering valve operable between an open position and a closed position and an air metering valve operable between an open position and a closed position. The fuel injector also includes a valve seat located within the body proximate to the discharge end and includes an orifice extending therethrough along the longitudinal axis. A needle is reciprocally mounted along the longitudinal axis between an open position and a closed position. The needle has an upstream end, a downstream end, and a needle channel extending therethrough along the longitudinal axis. The needle engages the valve seat in the closed position. A guide is disposed along the longitudinal axis such that the upstream end of the needle is reciprocable within the guide.

Abstract: An outboard motor is mounted with a multiple-cylinder engine having cylinders to which intake air is distributed through the intake manifold unit of an intake unit, respectively. The intake manifold unit comprises an intake manifold body formed of a synthetic resin, an idling air control (IAC) valve for regulating a quantity of intake air into the intake manifold unit in an idling operation state, a valve holder to which the IAC valve is operatively connected in a floating manner, and an elastic member through which the IAC valve is mounted to the valve holder. The IAC valve, the elastic member and the valve holder are coupled integrally with each other and mounted to the intake manifold body in the floating state.

Abstract: A low pressure EGR system suitable for use as a passive retrofit system is disclosed for moving vehicles equipped with a diesel engine. The EGR loop inlet is positioned upstream of the exhaust particulate filter and downstream of the turbine to utilize backpressure created by the exhaust particulate filter to insure EGR flow in the loop. A catalyzed soot filter in communication with the EGR pickup insures cleansed EGR gases at the EGR return downstream of the air filter and upstream of the compressor. A corrugated EGR line provides cooling of the EGR gases.

Abstract: A method and system for the intake air separation within an internal combustion engine is disclosed. The disclosed embodiments of the intake air separation system includes an intake air separation device adapted for separating the intake air into a flow of the oxygen enriched air and a flow of nitrogen enriched air; an intake air circuit adapted to deliver intake air to the air separation device, and a purge air circuit adapted to deliver a flow of sweep air or purge air to the intake air separation device to increase the effectiveness of the air separation. The intake air separation device includes a first outlet in fluid communication with the intake air separation device and adapted to receive a flow of the oxygen enriched air and purge air as well as a second outlet also in fluid communication with the intake air separation device and adapted to provide the glow of nitrogen enriched air to the intake manifold for use in the combustion process.

Abstract: A spray bar pair for use in the performance car industry is disclosed. The spray bar pair may be installed in a spray bar plate for mounting in the air flow from the throttle valve and injects a well mixed mixture of fuel and gas into the intake manifold of an engine. The spray bar pair utilizes carefully a chosen pattern of spray apertures set at such angles in the spray bar pair to ensure proper mixing. Several methods of use for the improved spray bar pair are given.

Abstract: An insert adapted to be placed between a carburetor or a throttle body and an intake manifold of an internal combustion engine is provided with a fuel manifold, a nitrous oxide manifold, and one or more burst diaphragms in a wall of said insert. Said manifolds are arranged one over the other and across an opening in said insert. A plurality of orifices extend along the length of each manifold, and are arranged to direct flow outward, downward, and radially relative to the axial flow of the fuel-oxidizer mixture through the insert.

Abstract: A single needle diaphragm type carburetor has a throttle valve in a mixing passage with a venturi, an idle fuel nozzle downstream of the throttle valve when in its idle position, a high speed fuel nozzle preferably disposed within the venturi upstream of the throttle valve and a supplemental air bleed passage opening into the mixing passage upstream of both the idle and high speed fuel nozzles. Both the idle and high speed fuel nozzles communicate with each other through a transfer passage and are fed from the same fuel circuit controlled by a single needle valve which limits the fuel flow to them. At idle or low speed and low load engine operation air supplied by the supplemental air bleed passage is mixed with fuel supplied to the idle fuel nozzle. At wide open throttle, air from the air bleed passage is routed near the idle fuel nozzle, and mixed with the fuel supplied to the high speed nozzle.

Abstract: A supplemental nitrous oxide and fuel injection system for use with an internal combustion engine, which includes the unique properties of variable flow-rate control of the supplemental injection system and direct cylinder injection methods. Where an engine is normally controlled by the driver with the (0-100%) throttle control of the existing air/fuel system, this supplemental nitrous oxide and fuel injection system is linked to the existing throttle control and controlled in the same manner. In addition, this system also provides a direct cylinder injection method that completely bypasses the existing intake manifold and carburetor/fuel injection.

Abstract: An air amplifier and method and system for using a source of compressed oxygen enhancer, such as nitrous oxide, to increase air flow into an internal combustion engine, providing increased power gain for the engine over the power gain provided by the addition of the oxygen enhancer alone. A source of compressed gas is fed into an air amplifier positioned in the air intake tube for the engine, such as a hose or other conduit which leads to, for example, the throttle body for the fuel injector system. The compressed gas, which includes or is made up of an oxygen enhancer, such as nitrous oxide, is fed into the air amplifier near the inner edge of the air intake tube, producing a Coanda effect, such that air intake into the engine is greatly increased. The device is useful in conjunction with oxygen enhancer systems, such as nitrous oxide kits for feeding nitrous oxide into the throttle body for fuel injected internal combustion engines.

Abstract: A fuel injector for a spark-ignition, internal combustion engine includes a fuel injector body having inlet and discharge ends. The discharge end includes a fuel swirl disk for inwardly directing a plurality of fuel streams to provide a turbulent swirling stream of fuel directed axially outwardly. A valve regulates the outward axial flow of the turbulent swirling fuel stream. A mixing chamber having an air supply provides a flow of assist air and a discharge passageway. The mixing chamber receives the turbulent swirling fuel stream which is atomized as it enters the mixing chamber and the atomized fuel mixed with the assist air is directed outwardly through a discharge passageway.

Abstract: A combustion air management and emission control system injects supplemental air directly into combustion chambers of a diesel engine in order to reduce total particulates in exhaust gases being emitted from the engine. A portion of intake air flowing toward an intake manifold of the engine is diverted to a compressor so that controlled quantities of pressurized supplemental air can be injected directly into each of the combustion chambers while the piston within the combustion chamber is in its expansion and/or exhaust strokes. At least a portion of the diverted intake air can be directed through a selectively permeable membrane device so that oxygen-enriched air and nitrogen-enriched air are produced. At least a portion of the oxygen-enriched air can be supplied to the compressor so that the supplemental air being injected into the combustion chambers will contain a desired, elevated amount of oxygen.

Abstract: A system and method for improving performance and fuel efficiency of a combustion engine by providing an oxygen enriched gel which is inserted near an air intake, where the gel is stored within a container formed from a gas permeable membrane which is sufficiently porous so as to enable the gel to gradually evaporate. The evaporating gel releases oxygen, which is drawn into the air intake, resulting in reduced emissions and improved performance of the engine. No modifications to the combustion engine are required to use the system. The gel is inexpensive, and the gel container is preferably replaced or refilled approximately as often as an oil change is performed.

Abstract: An engine running control apparatus includes a full-closure state detecting device for outputting a full-closure detection signal when the throttle valve is in the fully closed state, a control device for controlling the open degree of the air control valve, a time-measuring device for counting up a predetermined period of time in response to the full-closure detection signal, an engine speed detecting device for detecting the rotating speed of the engine and an initial value setting device for setting up an engine speed at which control of the degree of the opening is started by the control device, in response to the full-closure detection signal.

Abstract: A novel laminar flow nozzle for fuel injected racing cars is described herein. One novel feature comprises a narrow angle between converging conduit component channels. These channels, in turn, supply vaporized fuel and nitrous oxide to the main chamber of the nozzle. Another important novel feature is the integral structure of the nozzle; the conduit components, generally rigid and cylindrical in shape, are physical integral components of the nozzle. The result of our invention is a nozzle with a smooth laminar flow of gases which results in less turbulence and greater horsepower.

Abstract: The present invention relates to a nitrous oxide injection device and system, and a method of installation of the device and system, and, in particular, to a self-contained, easy to install nitrous oxide device that provides fuel delivery that varies with nitrous oxide tank pressure by way of a manifold that is pressurized by a bleed orifice from the nitrous oxide source. The pressure from the manifold is transferred by a connection to the fuel pressure regulator of the vehicle, so that fuel delivery varies proportionally to the pressure of the nitrous oxide source.

Abstract: A method and system for late cycle injection of oxygen enriched air into the combustion chamber of an internal combustion engine is disclosed. The late cycle oxygen injection system is part of an airflow management system that effectively controls the use of oxygen and nitrogen available in the intake air. The preferred system comprises an intake air separation device adapted for separating a prescribed portion of intake air into a flow of oxygen enriched air and a flow of nitrogen enriched air. The system includes an oxygen enriched air flow circuit extending from the intake air separating device to one or more combustion chambers and a control device adapted for controlling the introduction of the oxygen enriched air into the combustion chambers late in a combustion cycle in response to selected engine operating conditions such as engine speed or engine load or both.

Abstract: A fuel injection system having a common rail pressure reservoir filled with high-pressure fuel and having a dual-fuel injector for a bi-fluid injection of fuel and an additive fluid into an internal combustion engine. The system includes a first 2/2-way valve in the injection line between the common rail pressure reservoir and a pressure chamber encompassing the injector needle of the dual-fuel injector as well as a second 2/2-way valve, whose inlet is connected via a supply line to the injection line at a point between the first 2/2-way valve and the pressure chamber, and whose outlet is connected to the low-pressure fuel side by way of an outlet line. As a result, the otherwise conventional 3/2-way solenoid control valves, which are significantly more complex technically, can be replaced by more reasonably priced 2/2-way valves. At the same time, this raises the possibility of shifting the quantity metering for additive fluid to a single metering valve that serves an entire group of injectors.

Abstract: An emission control system for reducing total particulates and NO.sub.X emissions from the exhaust of a diesel engine includes an air supply system that supplies oxygen enriched air to an air intake of the engine. The air supply system may include a selectively permeable air separating membrane device for producing the oxygen enriched air. In order to effectively utilize the increase in the concentration level of oxygen in the intake air, the amount of fuel being supplied to the diesel engine also is increased at a minimum in proportion to the increased concentration level of oxygen in the intake air. The increase in the amount of such fuel being supplied to the diesel engine can be adjusted by an electronic fuel injection system used on such diesel engines. In addition, the electronic fuel injection system is used to retard the injection timing of the engine.

Abstract: An idle intake control device provided with a backflow preventing means for preventing a backflow near an idle intake regulating valve and producing only a forward flow in order to prevent idle intake air containing combustion products from flowing back and being adhered to an idle intake regulating valve in an idle intake passageway for bypassing an intake regulating valve provided in an intake passageway of the engine.

Abstract: There is disclosed herein an electronic control module assembly 30 for use in an internal combustion engine, wherein the engine includes an intake manifold 10 with N air inlet port(s) 14 and a throttle body 20 with N air outlet port(s) 24 where N=(1 or 2). One embodiment of the assembly 30 comprises: (a) a housing 32 having opposed upper and lower mounting surfaces 34/36 and an outer surface 38 about the housing, and N bore(s) 42 through the housing, wherein each bore has an upstream port 44 defined in the upper mounting surface 34 and a downstream port 54 defined in the lower mounting surface 36; (b) an electronic control module 60 for controlling one or more sub-systems of the engine; and (c) means 70 for attaching the electronic control module 60 to the outer surface 38 of the housing 32.

Abstract: The present invention relates to a nitrous oxide injection device and system, and a method of installation of the device and system, and, in particular, to a self-contained, easy to install nitrous oxide device that provides fuel delivery that varies with nitrous oxide tank pressure by way of a manifold that is pressurized by a bleed orifice from the nitrous oxide source. The pressure from the manifold is transferred by a connection to the fuel pressure regulator of the vehicle, so that fuel delivery varies proportionally to the pressure of the nitrous oxide source.

Abstract: A novel method of operating an internal combustion engine employs a selectively gas permeable membrane to provide either oxygen or nitrogen enriched air feed to beneficially affect engine performance. By feeding enriched air from a membrane unit such performance parameters as reduced NOx emissions, lean burn limit, engine power, and reduced cold start emissions can be enhanced relative to feeding ambient air. The selectively gas permeable membrane unit further includes a nonporous membrane (i) having an oxygen/nitrogen selectivity of at least 1.4 and a permeability to oxygen of at least 50 barrers; (ii) formed from an amorphous copolymer of perfluoro-2,2-dimethyl-1,3-dioxole; and (iii) being at a temperature below the glass transition temperature of the amorphous copolymer.A cylindrical module having many substantially parallel aligned small diameter hollow fiber membrane structures is ideally suited for carrying out the novel method.

Abstract: A cylinder wall fuel injector is provided with a deflector that causes a fuel spray to be deflected from its normal path directly across a cylinder and perpendicular to a centerline of the cylinder. The deflector is positioned between an opening in the tip of the fuel injector and the cylinder into which the fuel is sprayed. The deflector causes the fuel to be redirected away from a direct line toward the exhaust port of the cylinder.

Abstract: A fuel injection valve for an internal combustion engine includes a metering injection valve and a fuel vaporizer that is arranged upstream from an outlet spray orifice of the injection valve (10) on the intake end and has a vaporizer area with at least one assigned electric heating element. To assure in particular that the fuel vaporizer guarantees very good fuel processing in all heating states, i.e., in heating operation for complete or partial vaporization and in the unheated state, the vaporizer area that accommodates at least one heating element is closed at the outlet end by an outlet valve.

Abstract: An air assist device comprising a slit shaped air intake formed in the inner wall of an intake duct around a throttle valve. The assist air is taken in from the air intake ports. A downstream side edge portion of the opening of the slip shaped air intake port is formed into an arc shape which extends along a downstream side edge portion of the outer peripheral end face of the throttle valve when the throttle valve is positioned at an idling position.

Abstract: The invention is directed to a method and an arrangement for enriching the oxygen content in the intake air of an internal combustion engine. To enrich the oxygen content, air is conducted through a membrane which is primarily permeable for oxygen molecules. This membrane is mounted in an enrichment channel which opens into the intake channel of the engine. The oxygen content in the intake channel is continuously detected by at least one sensor device. On the one hand, a reduction of the toxic emissions of the engine is provided while, on the other hand, an increase in the power of the engine is simultaneously provided. This is achieved with a drivable actuator device which changes the concentration of the inducted air as well as the oxygen-enriched air in dependence upon the detected oxygen content.

Abstract: The fuel injection nozzle (10) includes a nozzle tip (16) that is formed in the shape of a substantially symmetrical double-sided wing having a leading edge (40) for facing the oncomning air stream passing through the air inlet manifold of an internal combustion engine. The arcuate walls (46 and 48) of the nozzle tip diverge on opposite sides of the cord line (44), and the internal conduit (22) guides the liquid nitrous oxide to move through the nose (50) of the nozzle tip and impinge with the flow of fuel moving through the adjacent internal conduit (24). A zone of low pressure is induced by the air movement (42) passing about the wing-shaped nozzle tip at a position behind the leading edge (40) of the nozzle tip, and the nitrous oxide tends to change states from liquid to gas as it emerges from the internal conduit (22) and moves through the exit port (52).

Abstract: A fuel delivery system for an internal combustion engine having an intake air metering device, leading to individual combustion chambers several fuel injection valves, each of which is assigned to one combustion chamber, and a central fuel vaporizer to which fuel can be supplied by a fuel metering device. To reduce pollutant emissions during the warm-up phase of the internal combustion engine after start-up, fuel vapor generated in the fuel vaporizer can be added to the intake air for the combustion chambers downstream from the intake air metering device.

Abstract: An air inlet auxiliary device provides additional air to an inlet manifold of a vehicle. The auxiliary device includes a main body, a filter assembly mounted to a first end of the main body, a control seat mounted to a second end of the main body and in fluid communication with the inlet manifold, and first and second cylindrical members mounted in the main body. Air passages are defined in the first and second cylindrical members. When the engine of the vehicle is idling or runs under a speed slower than a pre-determined value, more additional air is supplied to the air manifold, and when the engine is running under a speed faster than the pre-determined value, only a small additional amount of air is supplied to the inlet manifold.

Abstract: In a cast cylinderhead of a multi-cylinder internal combustion engine wherein gas flow channels (exhaust gas and intake air flow channels) and at least one longitudinal gas flow passage with branch passages extending between the longitudinal gas flow passages and particular gas flow channels are formed in the cylinderhead, the gas flow channels, any longitudinal gas flow passage and all the branch passages are formed by a single-piece casting core structure.

Abstract: A fuel supply module located between the carburetor and intake manifold is disclosed for spraying fuel and nitrous oxide. The module has two pairs of adjacent conduits that are perpendicular to each other and span the intake passage. One conduit in each pair has nozzles for spraying fuel and the other conduit has nozzles for spraying nitrous oxide. The conduit for spraying fuel being downstream of the conduit for spraying nitrous oxide.

Abstract: An air and fuel system for carburetor and fuel injection engines that regulates the temperature of air and fuel that is mixed in the carburetor or fuel injector prior to introduction to the cylinders of the engine. A heater and associated filter located at the air intake side of the carburetor are activated by circulating heated fluid (coolant) contained within the engine cooling system. The coolant passes through the heater and an isolated chamber or conductor and the fuel line passes inside the coolant line within the heater surroundings so that air and fuel can be temperature regulated. Valves in the fuel line allow for proper mixture of air and fuel. A filter is sized to fit inside or outside the heater, and the heater and filter are encompassed by a cover to hold the components together.

Abstract: The present invention relates to a process for controlling the proper operation of an air-assisted injector (17) during the start-up phase of an internal combustion engine (11). This injector is adapted to deliver a predetermined quantity of fuel to the engine. The process according to the invention is characterized in that it comprises:a verification a posteriori, during a stabilized idle phase, that a predetermined quantity of air can be injected during the air assistance phase.The present invention also relates to a device which implements this process and is particularly applicable to the field of automotive electronics.

Abstract: An air intake arrangement for an internal combustion engine comprising: a main air intake conduit leading to a gas intake valve (241) for respective engine cylinders (206) and including a main air intake passage (202), a main collector chamber (204) and independent branching air intake passages (205) for the respective engine cylinders (206) connected in series; a throttle valve (203) disposed in the main intake air passage (202) for controlling the flow rate of air passing therethrough; an auxiliary air intake passage (210) bypassing the main air intake conduit, wherein an inlet port of the auxiliary air intake passage (210) opens into the main air intake passage (202) at the upstream of the throttle valve (203), and an outlet port (213) of the auxiliary air intake passage (210) opens into the respective independent branching air intake passage (205) near the gas intake valve (241) for the respective engine cylinders (206) in such a manner that gas blown-out from the auxiliary air intake passage (210) induc