Abstract: A switchable air intake system for a multicylinder internal combustion engine has at least one short and one long intake manifold whose cross sections are controllable by at least one regulating unit as a function of operating parameters (in particular the rotational speed of the internal combustion engine). The short intake manifold for a first cylinder bank row and the long intake manifold for a second cylinder bank row of the internal combustion engine, are controllable via a joint regulating unit (56, 58).

Abstract: An intake manifold is provided to an internal combustion engine including a first and second cylinder heads each having an intake port. The first and second cylinder heads are distant from each other, and defining a crank angle therebetween. The intake manifold includes a manifold body that defines intake passages each connecting with each intake port. Each intake passage has an interior divided into divisional passages. A butterfly valve communicates and blocks at least one of the divisional passages. Tanks are formed integrally with the manifold body for accumulating negative pressure in the manifold body. The tanks include a first tank, which is provided to the first cylinder head, and a second tank, which is provided to the second cylinder head. An actuator operates the butterfly valve by being applied with negative pressure from the plurality of tanks. The manifold body has a communication passage that communicates the first tank with the second tank.

Abstract: In an intake system for an engine incorporated with a resonance chamber (32), a variable communication unit (50) for controlling the communication between an intake passage with the resonance chamber comprises an outer tube (51) having an open axial end (51a) and an opening (51b) defined in a circumferential wall thereof for communication with the resonance chamber and an inner tube (52) rotatably and coaxially received in the outer tube, the inner tube being provided with a communication inlet port (52a) at an axial end on a same side as the axial end of the outer tube and an opening (52b) in a circumferential wall thereof for defining a communication outlet port (50a) jointly with the opening in the outer circumferential wall of the outer tube.

Abstract: In a variable air induction apparatus, a valve element is switched between one side to open a first air intake passage and close a second air intake passage, and the other side to open the second air intake passage and to close the first air intake passage. The first air intake passage and the second air intake passage have lengths different from each other. The valve element is fixed on a shaft member to rotate integrally with the shaft. A driving device applies a driving force to rotate the shaft member. An urging device urges the shaft member to rotate the valve element to be switched to any one of the one side and the other side.

Abstract: An intake air device includes a first intake passage the length of which is fixed; a second intake passage the length of which can be changed, and a downstream-end of which is joined to a downstream-portion of the first intake passage; a first valve the opening degree of which can be changed, and which is provided in the first intake passage; a second valve the opening degree of which can be changed, and which is provided in the second intake passage; and operation means for operating the first valve and the second valve according to the operating state of the internal combustion engine. With this configuration, the cross sectional area perpendicular to the longitudinal direction of at least one intake passage that is used can be appropriately changed according to the operating state of the internal combustion engine.

Abstract: An engine air intake device for an outboard motor includes a plurality of main intake pipes corresponding to each cylinder. First and second branch pipes extend from an upstream end of each main part. The first branch pipes are longer than the second branch pipes. The second branch pipes each include a valve and are selectively closed. The first branch pipes open into a first surge tank. The second branch pipes open into a second surge tank that is formed separately from the first surge tank. In operation, the valves of the second branch pipes are open when the engine is operating in high engine speed and are closed at low-to-medium speeds.

Abstract: An air intake system for an internal combustion engine has at least one air box and a short duct for each cylinder. Each duct can be extended to provide higher torque at low speed. At high speed, the shorter duct length can be selectively provided for enhanced engine performance.

Abstract: An in-line resonator for an air induction system of an internal combustion engine is provided. The system includes a resonator housing, an upstream duct, a downstream duct, a conduit, a partition, and a sleeve. The conduit extends through the resonator housing connecting the upstream duct and the downstream duct. The partition is moveable within the resonator housing and divides the housing into an upstream chamber and a downstream chamber. The downstream chamber, the conduit, and the downstream sleeve cooperate to form a first Helmholtz resonator that is in fluid communication with the downstream duct. The upstream chamber, the conduit, and the upstream sleeve cooperate to form a second Helmholtz resonator that is in fluid communication with the upstream duct. Further, a means is provided to axially move the partition to vary the volume of the chambers concurrently with the length and/or area of the passages.

Abstract: An outboard motor includes an upright engine in which a plurality of cylinders are arranged vertically, an engine cover covering the engine, and an intake system for the engine. The intake system includes an intake manifold disposed on a side of the engine and provided with a surge tank and an intake pipe, in which the surge tank is arranged on the side of the engine inside the engine cover, the intake pipe is arranged on the inner surface side of the engine cover therein in a manner that the surge tank and the intake pipe are arranged parallel to each other.

Abstract: A variable intake system of a vehicle includes a plenum into which an external air is flowed, an intake manifold comprising a plurality of runners connected with the plenum and respectively guiding the air of the plenum into a plurality of cylinders, and a varying unit controlling a length of the runners according to a vehicle driving condition.

Abstract: A variable valve comprising a first cylinder having an aperture and a second cylinder having a second aperture. The first cylinder moves between a first position and a second position. Preferably, the second cylinder moves in cooperation with the first cylinder such that the first aperture and the second aperture form a variable sized opening when the first cylinder moves from the first position toward the second position. The first aperture and the second aperture preferably rotate. The variable sized opening is preferably in a closed position when in the first position. The valve comprises a block body including a passage for allowing air to pass therethrough. The first cylinder and the second cylinder are coupled to the block body and configured in a predetermined position such that the variable sized opening is in communication with the passage. The valve also includes an axle for driving the first cylinder and the second cylinder.

Abstract: In order to provide an intake flow rate detecting apparatus of an internal combustion engine which accurately compensates for an air flow meter detection error due to intake pulsation so as to make it possible to detect an intake flow rate more accurately, regardless of the of type of flow rate control mechanism, an intake flow rate detecting apparatus according to one embodiment of the invention includes a throttle valve which is provided in an intake passage and which adjusts a rate of the air that is taken into a combustion chamber of an internal combustion engine, at least one flow rate control mechanisms which are provided between the throttle valve and the combustion chamber and which control an air flow rate between the throttle valve and the combustion chamber, and a flow rate sensor which is provided upstream of the throttle valve in the intake passage and which detects a flow rate of air flowing through the intake passage.

Abstract: An intake manifold includes a permanent runner which provides airflow communication between a plenum volume and a plurality of engine cylinders. An active runner assembly retracts into and extends from the permanent runner assembly in response to a drive system which communicates with a controller to selectively change the length of the intake manifold assembly to optimize performance. The permanent runner assembly includes a plurality of fixed length passages and the active runner assembly includes a plurality of active runner passages. Each active runner passage telescopes in and out of a respective fixed length passage to vary the effective length between the plenum and the engine cylinder.

Abstract: A continuous variable suction system wherein the inner rotor is additionally installed at the inner side of the outer rotor to increase the variable scope of the suction runner length such that the runner length of an optimal suction air passage per speed and load of an engine can be embodied to enhance the engine's performance. A dual rotor structure is formed to reduce the volume of the inner rotor, thereby decreasing the size of the surge tank, whereby lightness of the suction system can be realized and the manufacturing cost can be also saved by minimizing the size of the suction system.

Abstract: A simplified variable intake manifold is disclosed for use with an internal combustion engine. The manifold utilizes a single valve actuator to vary the resonant frequency of a pair of plenums. The two plenums are joined by first and second communication passages of differing lengths connected to provide cross flow between two plenums. Each plenum has an inlet for receiving intake air from a throttle body and a group of runners adapted for connection with a like group of engine cylinders to direct inlet air from the plenums to combustion chambers of the cylinders. A control valve having an elongated shaft extends through the first and second communication passages and includes separate blades rotatable with the shaft to open or close the passages to provide at least three modes of tuning of the plenums. A stepper motor or other suitable device acts upon the shaft to rotate the blades within the communication passages.

Abstract: The present invention provides a variable runner length intake air manifold operative to optimize the performance of an internal combustion engine over a wide range of engine speeds. The manifold includes a housing formed of upper and lower halves fixedly attached via conventional fastening means. The upper and lower halves define a plurality of runners having constant cross-sectional areas but different cross-sectional shapes. A tapered drum is disposed within the housing and includes one open end and a plurality of openings formed in the outer surface that communicate with corresponding runners of the housing. The tapered drum is rotatably mounted within the housing such that the effective runner length or airflow path of the manifold is made adjustable by varying the angular position of the tapered drum disposed within the housing.

Abstract: A valve, particularly a switching cylinder, for opening and closing a pipe, especially for use in an intake manifold for a multi-cylinder internal combustion engine having an air distribution chamber and individual intake pipes positioned next to one another which terminate in a flange, in which the valve is positioned in an individual intake pipe to close or open the respective intake pipe, and the valve has at least one sealing system mounted in a radially movable manner such that, in the closed position, it presses against the pipe inner wall to form a seal, and in the open position and in the pivot range from the closed position to the open position, it forms a gap between the valve and the pipe inner wall.

Abstract: An intake system for an internal combustion engine having an intake plenum and at least one intake pipe which branches off from the intake plenum and which is composed of at least two intake pipe parts that are divided longitudinally. The intake plenum together with one of the intake pipe parts forms a single integral base part. The second intake pipe part is configured as an interchangeable insert that also forms one wall shell of the intake plenum.

Abstract: An intake manifold includes a plenum volume 14 mounted for movement within a housing 20 in response to a drive system 22 to define an effective runner length. A multiple of deformable runner passages 18 include a flexible section 26 such that as the plenum 14 extends and retracts within the housing 20, the flexible section 26 accommodates the difference in length while the housing 20 provides structural support therefor. An intake conduit 12 likewise includes a flexible section 26 to accommodate movement of the plenum 14. In operation at low engine speeds, the plenum 14 is driven to extend the deformable runner passages 18 to increase the length between the plenum 14 and the engine cylinders 16. As the engine speed increases, the plenum 14 is driven to shorten the deformable runner 18 for maximum speed operation.

Abstract: An intake manifold includes a plenum volume 14 mounted for movement within a housing 20 in response to a drive system 22 to define an effective runner length. A multiple of deformable runner passages 18 include a flexible section 26 such that as the plenum 14 extends and retracts within the housing 20, the flexible section 26 accommodates the difference in length while the housing 20 provides structural support therefor. An intake conduit 12 likewise includes a flexible section 26 to accommodate movement of the plenum 14. In operation at low engine speeds, the plenum 14 is driven to extend the deformable runner passages 18 to increase the length between the plenum 14 and the engine cylinders 16. As the engine speed increases, the plenum 14 is driven to shorten the deformable runner 18 for maximum speed operation.

Abstract: Supplementary control valve devices (26) may be utilized to control the flow of a fluid within an intake passage (16) of a reciprocating piston internal combustion engine and may include a valve member (56) axially reciprocally disposed within the intake passage and at least partially defining a solenoid armature (60). First and second solenoids (38, 50) are provided on opposite sides of the solenoid armature to reciprocally move the valve member between a valve open position and a valve closed position. Sealing contact faces are preferably defined by pole faces (68, 70) of the second solenoid and a peripheral fluid flow passage (34) extends through apertures (46) defined within the second solenoid and between the sealing contact faces. The valve member closes the peripheral fluid flow passage when pressed against the sealing contact faces. Springs (62, 64) preferably bias the valve member towards a central position between the first and second solenoids.

Abstract: An air intake channel system for internal combustion engines is provided. The system includes several air intake channels each of which is formed by at least a first and a second channel member. A common channel member is allocated to two of the air intake channels and includes two air inlet openings. By pivoting the common channel member, the length of the air intake channels can be jointly varied.

Abstract: A continuously variable Helmholtz resonator for a vehicle air intake system having a vibratory input to the resonator wall to dynamically adjust the cancellation frequency for time-varying acoustical signals, and at least one of mean resonator volume control, mean resonator neck length control, and mean resonator neck diameter control whereby control of both the dynamic and the mean properties of the resonator provides a wide tuning spectrum and facilitates canceling of time-varying acoustical signals.

Abstract: An internal combustion engine has an intake device (1), the intake pipes (5 to 8) for the intakes of cylinders of the internal combustion engine and actuators for adjusting the effective pipe lengths of the intake pipes (5 to 8) by closing or opening at least one opening of the intake pipes (5 to 8) up to a hollow body and at least one actuator for controlling the actuators. Within a first speed range whose upper limit is a first threshold value (N1), the actuators are moved into a closed position. For a speed (N), exceeding a first threshold value (N1) and being less than a second threshold value (N2), the actuators are moved into a leakage position. For a speed exceeding the second threshold value (N2), the actuators are moved into an open position.

Abstract: An air intake duct system for internal combustion engines, and in particular for V-engines, comprises a plurality of air intake ducts (10, 12). Each air in-take duct is formed by two duct portions (18), and (20) and (22), respectively. The second duct portions (20, 22) are arranged to swivel about a swivelling axis (34) and (36), respectively, for varying the length of the air intake duct. According to the invention the two swivelling axes (34, 36) are supported in a common bearing part (44) which comprises two swivelling axis bearings each provided for one of the two swivelling axes (34, 36).

Abstract: An intake manifold (10) for a multi-cylinder internal combustion engine includes a tubular intake distributor (12) from which a plurality of long intake tubes (13) extend and lead to the individual cylinders. Short intake tubes (14) likewise extend from the intake distributor and open into the respective associated long intake tubes (13). The intake distributor (12) and the long and short intake tubes (13, 14) are formed from a one-piece housing (11) which has a cavity (21) which intersects the short intake tubes (14). In this cavity (21) a control element (15) is installed, which includes flaps (16), flap frames (17), a shaft (19) and a control element frame (18). By moving the shaft (19) either rotationally or translationally, the short intake tubes (14) can be opened or closed. In contrast to arrangements known in the prior art, the control element (15) has no sealing elements which can catch or jam during assembly.

Abstract: A number of embodiments of acoustical devices for improving either or both the intake and exhaust sounds emanated from an internal combustion engine. This is achieved by employing acoustical devices which are configured so as to discharge the desired sound waves to the atmosphere rather than by attempting to dampen the undesired sound waves generated in the system.

Abstract: A first intake pipe has one end connected to a second side of the surge tank which faces a second cylinder bank, and a second intake pipe has one end connected to a first side of the surge tank which faces a first cylinder bank. Adjacent the intake pipe ends, the first and second intake pipes are inversely bent near the second and first cylinder banks respectively, and have middle portions crossing below the surge tank and have other ends connected to the first and second cylinder banks. The first and second intake pipes are arranged in an alternating position in the cylinder-row direction. First and second branch pipes have upper ends connected into the surge tank and lower ends connected to adjacent other ends of the first and second intake pipes. Variable intake elements are disposed at the upper ends of the branch pipes to open and close.

Abstract: An intake system of an outboard motor including a vertically arranged V-type engine comprises, an intake manifold connected to the intake ports, a surge tank connected to the intake manifold and disposed at a rear side from a central portion of the engine, a throttle body provided with a throttle valve, a plurality of intake passages for high revolution operation of the engine. The intake passages for high revolution operation extend from the surge tank and are communicated with the intake manifold, and the intake passages for low/intermediate revolution operation extend from the surge tank and are joined with the intake passages for high revolution operation, respectively. Each of the intake passages for low/intermediate revolution operation has a length longer than that for high revolution operation. A valve open/close mechanism is also disposed for opening/closing all at once portions upstream side of the joined portions of both the intake passages of the engine.

Abstract: An air intake system for intake air of an internal combustion engine comprising a filter insert (19) in a housing (10) connected to the air conducting system by a plurality of inlets (13) and an outlet (22). The air inlets are provided with individual intake nozzles or fittings and lead to a single common air chamber (20) in the filter housing. The inlets (13) can be individually opened and closed by flap valves (24), thereby allowing the acoustics to be influenced favorably and enabling, for example, the respective intake fittings to be connected or disconnected depending on the temperature. The intake system requires only a limited number of components, and the design of the preferably wedge-shaped air chamber minimizes flow losses in the housing, which in turn decreases the intake noise. Shunt resonators (28) can also be formed using cover elements (29) and (30).

Abstract: A switching-type intake pipe for internal combustion engines comprises an intake duct with a shorting aperture. The shorting aperture can be closed and opened by a switching flap. The switching flap is connected via a non-rigid connection with a flap lever. The connection between the flap lever and the switching flap is formed by a plate on the one side and a calotte on the other side. Thus, a tiltable connection, which is easy to manufacture and install, is produced between the switching flap and the flap lever.

Abstract: A method and system of controlling a vacuum-driven actuator in a vehicle. The method includes determining an amount of vacuum available to actuate the actuator, determining whether the available vacuum is sufficient to actuate the actuator, actuating the actuator only when the available vacuum is sufficient, and preventing actuation of the actuator when the available vacuum is insufficient.

Abstract: An intake device for an internal combustion engine including a mounting flange (10) for mounting to a cylinder head of an internal combustion engine and a plurality of intake manifolds (11-14) which open into a common collecting chamber. The mounting flange (10) and upper shells (23, 24, 25, 26) form a first component; lower shells (27, 28, 29, 30) form a third component, and a central, second component (31) is provided between the first and third components. The respective components are assembled to each other in such a way that the second component is fixed to the first component by a positive fit, and the third component is fixed to the second component in the same way. The components are preferably secured together by friction welding.

Abstract: A valve, particularly a switching cylinder, for opening and closing a pipe, especially for use in an intake manifold for a multi-cylinder internal combustion engine having an air distribution chamber and individual intake pipes positioned next to one another which terminate in a flange, in which the valve is positioned in an individual intake pipe to close or open the respective intake pipe, and the valve has at least one sealing system mounted in a radially movable manner such that, in the closed position, it presses against the pipe inner wall to form a seal, and in the open position and in the pivot range from the closed position to the open position, it forms a gap between the valve and the pipe inner wall.

Abstract: A method and system of controlling a vacuum-driven actuator in a vehicle. The method includes determining an amount of vacuum available to actuate the actuator, determining whether the available vacuum is sufficient to actuate the actuator, actuating the actuator only when the available vacuum is sufficient, and preventing actuation of the actuator when the available vacuum is insufficient.

Abstract: The present invention relates to a modified intake manifold having short runner valves in the manifold tuning valve. Anti-chatter devices are disclosed for reducing shaft chatter without placing friction on the shafts. A lost motion linkage is used to ensure closure of the short runner valves. Radiused seating surfaces are used for seating of the manifold tuning valve.

Abstract: An air intake channel system for internal combustion engines comprises several air intake channels (48,50) each of which is formed by at least a first and a second channel member (52,54). A common channel member (52) allocated to two air intake channels (48,50) comprises two air inlet openings (60,62). By pivoting the common channel member (52), the length of the air intake channels (48,50) can be jointly varied.

Abstract: An intake manifold includes a permanent runner which provides airflow communication between a plenum volume and a plurality of engine cylinders. An active runner assembly retracts into and extends from the permanent runner assembly in response to a drive system which communicates with a controller to selectively change the length of the intake manifold assembly to optimize performance. The permanent runner assembly includes a plurality of fixed length passages and the active runner assembly includes a plurality of active runner passages. Each active runner passage telescopes in and out of a respective fixed length passage to vary the effective length between the plenum and the engine cylinder.

Abstract: A structure in which an input shaft which is a member for connecting a cylindrical switching valve and a rotary mechanism, and the cylindrical switching valve are brought into contact with each other via a ball-like member. When this structure is employed, the ball-like member serves as a kind of ball joint, so that rotation can be smoothly transmitted even when there is an angle of inclination between the direction of the axis of rotation of the input shaft by which the rotary mechanism for rotating the cylindrical switching valve and the cylindrical switching valve are connected, and the direction of the axis of rotation of this switching valve.

Abstract: An air intake channel system for internal combustion engines, particularly V engines, comprises a plurality of air intake channels. The air intake channels are respectively formed by two channel portions. The second channel portions are pivotal about a respective pivot axis, to vary the length of the air intake channel. The pivotal channel portions are supported in recesses of the stationary channel portion. According to the invention, a slide element is arranged in the recess in such a manner that it abuts on a radial and an axial abutment surface.

Abstract: In a variable intake apparatus for a multi-cylinder internal combustion engine, each cylinder is allowed to communicate with each other through air intake passageways including at least a pair of air intake passageway portions. Further, an air intake control valve integrally provided with a pair of valve bodies is disposed at an opening which is formed at a partition wall. The partition wall is formed between the intake air collecting chamber and the air intake passageway. Further more, the air intake control valve is actuated according to engine speeds of the internal combustion engine such that the air intake passageway portion is opened and closed by one of the valve bodies whereas the opening in the partition wall is opened and closed by the other of the valve bodies.

Abstract: A shift drum (10), especially for use in an intake manifold arrangement for a multi-cylinder internal combustion engine, having an induction distributor, long individual suction pipes (27) that are arranged adjacent one another, and short individual suction pipes (28) that are situated interiorly. The shift drum (10) is arranged in a longitudinal bore (26) which intersects at least the short individual suction pipes (28). Shift drum (10) is further provided with radial seals (13) which seal the individual pipes (27, 28) from each other. Separate seals (12) are provided which are fixed in position on the shift drum (10) for sealing off long individual suction pipes (27) from short individual suction pipes (28) in a closed position.

Abstract: An adjustable intake pipe, especially for supplying combustion air to an internal combustion engine, which includes a collector chamber arranged in an essentially cylindrical control element. The collector chamber has a larger volume than required for the air supply, so the chamber is not used efficiently. In the invention, the collector chamber volume is used by arranging additional components of the intake tract defined by the intake pipe, i.e. of an internal combustion engine, within the collector chamber (11), for example, by arranging a resonance chamber (20) therein with the resonance chamber connected to the air supply system by through holes (19). This arrangement better utilizes the chamber volume and is particularly advantageous in motor vehicle engine compartments where limited space is available. The intake system also is more compact and has a lower overall weight.

Abstract: A compact intake manifold for an in-line six cylinder engine, having six independent runners of equal length emanating from a centrally disposed plenum and traveling in a substantially single plane. Runners serving the two most rearward and the two most forward engine intake ports begin travel in a path along the longitudinal axis of the engine and make only one turn of substantially 90 degrees toward the engine. Runners serving the two central intake ports also begin travel in a path along the longitudinal axis of the engine but take a somewhat serpentine path of one turn of substantially 180 degrees and one turn of substantially 90 degrees.

Abstract: A suction tube with a switching element for longitudinal adjustment of different tube sections (16), particularly a suction tube having a drum switch (12). The invention provides for sealing strips (29) or sealing rings (17) which are supported inside the suction tube casing (14). This results in a relative movement between the drum switch (12) and the sealing elements fixed to the casing. The positioning of the sealing elements in the suction tube casing (14) is advantageous for assembly and allows for better compensation of tolerances in the sealing gap between the drum switch (12) and the suction tube casing (14).

Abstract: A switching-type intake pipe (10) for internal combustion engines comprises an intake duct (11) with a shorting aperture (16). Said shorting aperture (16) can be closed and opened by a switching flap (18,18′). Said switching flap (18) is connected via a non-rigid connection with a flap lever (20). The connection between said flap lever (20) and said switching flap (18) is formed by a plate (32) on the one side and a calotte (26) on the other side. Thus a tiltable connection, which is easy to manufacture and install, is produced between said switching flap (18) and said flap lever (20).

Abstract: An apparatus (1) for mixing air and fuel in an internal combustion engine comprises at least two throttle bodies (2a, 2b) having an inlet and an outlet and at least two air chokes (8), each located at the inlet of one of the throttle bodies (2a, 2b) and coaxial with the throttle body (2a, 2b). Each air choke (8) has a portion (9) that is fixed and a portion (10) that moves coaxially relative to the fixed portion (9) between a first position in which the air choke (8) presents a first height (L1) and a second position in which the air choke (8) presents a second height (L2) that is greater than the first height (L1). The apparatus (1) further comprises at least two independent actuators (13) each moving one of the mobile portions (10) between the first and second positions, and at least two fuel injectors (11) located above the air chokes (8).

Abstract: A suction device used for an internal combustion engine includes a throttle passage, which is arranged on the upstream side, and also includes an air connector, a surge tank and suction manifolds which are arranged on the downstream side of the throttle passage. An opening section of the air connector arranged in the longitudinal direction on a side wall face of the surge tank is provided on a wall face corresponding to a position which becomes a substantial center of the suction manifold which is open to the surge tank. Due to the foregoing, intake air can be evenly distributed to the suction manifold, and lengths of the passages can be made equal to each other. Accordingly, the generation of a rumbling noise can be suppressed. Further, the suction manifold substantially encircles the outer circumferential wall faces of the surge tank and others.

Abstract: A fuel supply device is mounted to a motorcycle engine between two substantially identical air intake connections. The air intake connections each include a body portion with a projection and a flange, each extending radially from the body portion. Fasteners inserted through apertures in the flanges hold the air intake connections to the engine. The protrusion is preferably made of a resilient material, such as rubber. The flange is preferably made of a non-resilient material, such as aluminum. An aperture having an annular recess extends through the projection. The aperture is adapted to receive an internally threaded metal sleeve having an annular protrusion that surrounds the metal sleeve. A threaded fastener preferably extends through the metal sleeve and couples the fuel supply device to the projection. In the event that the fastener is excessively torqued during tightening the metal sleeve can spin in the aperture without damaging the projection.

Abstract: An apparatus (1) for mixing air and fuel in an internal combustion engine comprises at least two throttle bodies (2a, 2b) having an inlet and an outlet and at least two air chokes (8), each located at the inlet of one of the throttle bodies (2a, 2b) and coaxial with the throttle body (2a, 2b). Each air choke (8) has a portion (9) that is fixed and a portion (10) that moves coaxially relative to the fixed portion (9) between a first position in which the air choke (8) presents a first height (L1) and a second position in which the air choke (8) presents a second height (L2) that is greater than the first height (L1). The apparatus (1) further comprises at least two independent actuators (13) each moving one of the mobile portions (10) between the first and second positions, and at least two fuel injectors (11) located above the air chokes (8).