Abstract: In a method for introducing fuel into the combustion chamber of an internal combustion engine wherein compressed gas is drawn from the combustion chamber during the compression phase of a working cycle, mixed with fuel, and injected into the combustion chamber together with the fuel during the subsequent working cycle, an ignitible mixture must be provided at the point where ignition is initiated.

Abstract: An intake port of an engine cylinder is directed so as to introduce intake air flow into a combustion chamber in a desired direction. The intake port has a throat portion, extending upstream from a valve port and configured so as to meet the valve port at a given angle, and a transitional throat portion with a small radius of curvature between the throat portion and the valve port.

Abstract: A four stroke engine cylinder head (16) has two inlet pipes (19 and 22) which contain alternate acting inlet valves (14 and 15). Fuel/air induction strokes through valve (14) alternate with air only induction strokes through valve (15) giving an eight stroke cycle under half load. When gate valve (23) is moved by a control to the dotted position, this seals the air only inlet and opens port (25) to give fuel/air induction strokes over half load and a four stroke cycle. Air only induction strokes or eight stroke cycles under half load may also be achieved by cutting out some fuel injectors or injection strokes as the load permits.

Abstract: The tubular skirt (12) in the partition between the air ports (2, 3) supports the injector (11) and forms two fuel passages (19) emerging in the ports (2, 3) between two opposed lateral walls (15) each thinned to a bevel (16) toward the downstream end with a free edge (17) in the form of a thin blade and with a notch having concavity turned toward the downstream end, a region (23) of the internal face of each lateral wall (15) upstream of the bevel (16) preferably being struck by at least one jet of fuel coming from the injector (11).Application to fuel-injected engines with two inlet valves per cylinder.

Abstract: A cylinder head and induction passage arrangement for a three intake valve internal combustion engine wherein the center intake passage and its porting arrangement is directed so as to augment the tumble action caused by the side valve seats and their intake passages. The construction also provides that the center intake valve will be disposed so that there will be no shrouded area in the path of flame from the spark plug so as to ensure complete combustion. The cylinder head is made in such a way that the same cylinder head may be used for either bank of an engine having angularly inclined cylinder banks through the machining of only one face thereof.

Abstract: A preferred combustion chamber configuration for a piston engine includes two intake valves and one exhaust valve. The two identical intake valves and their associated induction system are arranged to promote separation of the two barrel swirl layers as established in the engine cylinder through the two valves. Further included, in a location containing the intake valves, is a large squish area for providing a fast burn rate in spite of spark ignition in just the richer one of the two barrel swirl layers. Such ignition therefore remains reliable and consistent even when no fuel is injected into the intake passage feeding the leaner swirl layer. Also included in the invention is an engine operating strategy which refrains from injecting fuel into the leaner intake passage until a central engine throttle valve is first at least effectively wide open. Drive-by-wire control coordinates the resulting throttled and unthrottled ranges of engine brake torque output.

Abstract: An induction system for an internal combustion engine having at least one intake passage that is configured to generate a tumble and swirl to the intake charge. This is accomplished by providing a masked section adjacent the valve seat so that the flow entering the combustion chamber is directed across the combustion chamber to generate the tumble action. There is also provided a secondary intake passage that delivers a charge to the combustion chamber in a substantially unrestricted fashion so as to permit high power outputs. The secondary intake passage has the flow through it controlled by a throttle valve that is closed under low and mid-range running conditions.

Abstract: A cylinder head and induction passage arrangement for a three intake valve per cylinder internal combustion engine that provides a compact configuration while at the same time maintaining an induction system that is tuned to provide optimum performance throughout the entire engine speed and load ranges. In addition, the intake passages and associated control valves for them are arranged so as to generate a tumble action in the combustion chamber under low and mid-range performance while permitting maximum charging under high speed, high load conditions. A single fuel injector injects fuel in such a way as to serve at least a pair of the intake passages.

Abstract: In an internal combustion engine there is provided a cylinder head; a plurality of cylinder head bolts for securing the cylinder head to a cylinder block; at least one engine cylinder; at least two intake valves and two exhaust valves controlling the flow of gases into and from the engine cylinder. A plane defined by the intake valves and a plane defined by the exhaust valves extend at an angle of between 0.degree. and 15.degree. to one another and have an inclined orientation to the longitudinal engine axis. An overhead camshaft extends parallel to the engine axis and is situated in a zone bounded by the cylinder head bolts. Respective valve bridges interconnect the intake valves with one another and the exhaust valves with one another, and rocker arms connect respective cams of the camshaft with the valve bridges, whereby the intake valves are simultaneously operated by one cam and the exhaust valves are simultaneously operated by another cam.

Abstract: An intake system for a multicylinder internal combustion engine includes a plenum for supplying air to the engine's cylinder, a plenum throttle for admitting air into the plenum, a low speed runner extending between the plenum and at least one intake port formed in the cylinder head, a high speed runner extending between the plenum and the intake port, and a secondary throttle interposed between the runners and the intake port, such that the secondary throttle controls flow in both the high speed and low speed runners.

Abstract: The injector has two calibrated holes that deliver two jets of fuel into a zone into which there open out defined holes for passing air that are formed in a spray-generating adapter which is fed with air from a channel that is substantially at atmospheric pressure. The air-passing holes are distributed and oriented in such a manner that when steep pneumatic gradients are applied across the holes, at low or medium engine loads, one of the two sprayed fuel jets is deflected towards the other and mixes therewith to form a single jet confined in one only of the two intake manifold ducts, while at high engine loads both of them are fed. The injector is suitable for fitting to internal combustion engines fed by a multipoint injection installation and having two intake manifold ducts per combustion chamber.

Abstract: A multicylinder, four-stroke internal-combustion engine is spark-ignited and has three intake valves and one exhaust valve which interact in the combustion chamber with valve openings having valve opening centers. The valve opening centers are situated on both sides of a longitudinal center plane of the internal-combustion engine. The valves are arranged so that a first intake valve and a second intake valve with their valve opening centers are situated on one side of the longitudinal center plane, whereas a third intake valve and the exhaust valve with their valve opening centers are situated on the other side of the longitudinal center plane.

Abstract: An induction system for a V-type engine that permits a compact engine configuration and the tuning of two different intake passages for each cylinder for different engine speed ranges. The shorter high-speed intake passages are served by the plenum chamber adjacent the cylinder bank while some of the other intake passages are served by the adjacent plenum chamber and others are served by the other plenum chamber.

Abstract: An induction system and control arrangement for a three valve per cylinder engine, wherein the induction passages are tuned to provide different effective lengths for different engine running conditions. In addition, a control valve arrangement is provided for controlling the flow to the combustion chambers through the valve seats to generate unrestricted flow under high-speed, high-load conditions and tumble and/or tumble and swirl for promoting turbulence under low-speed, low-load conditions.

Abstract: An intake system for an internal combustion engine includes first and second intake valve bores provided to face a combustion chamber and to be independently opened and closed by first and second intake valves, and first and second intake ports which are connected to the corresponding intake valve bores with a partition wall interposed therebetween and which communicate with a common intake passage. In a particular operation range of the engine, an imbalance is produced in the concentration of the air-fuel mixture flowing through the first and second intake valve bores into the combustion chamber on the basis of a difference between the amounts of fresh air flowing into the first and second intake ports. The intake system further includes a communication hole provided in the partition wall for putting the first and second intake ports into communication with each other. This provides for improvements in the lean combustibility and in the nature of the exhaust gas.

Abstract: A number of embodiments of cylinder head and intake port arrangements for multiple valve, internal combustion engines particularly those having three or more intake valves. The configuration promotes turbulence in the combustion chamber by inducing a tumble action even from the center intake valve seat. In addition, each of the valve seats and its associated flow passages are configured so as to provide optimum tuning for different engine speeds so as to improve the torque of the engine throughout its entire speed and load ranges and to provide good breathing efficiency throughout all engine speeds. Various porting and throttle and fuel injection systems are shown wherein siamesed intake passages are formed for at least two of the valve seats.

Abstract: A port throttle valve and an intake system incorporating the valve is disclosed. The valve is disposed between one of two intake runners delivering air to the intake port of an engine cylinder and includes a base member having an opening for delivery of air therethrough. The base includes a track in which is slidingly disposed, two adjacent valve plates each having an opening for registry with the opening in the base member to allow for the passage of air. When moved, in opposite longitudinal directions, the edges of the openings in the valve members move towards one another to terminate registry of the openings with the opening in the valve body.

Abstract: An internal combustion engine according to this invention is provided with intake ports each of which is formed to guide a flow of inducted air in a particular direction. Each intake port includes, in the vicinity of its corresponding intake opening to a combustion chamber, a bent port portion bent at a greater curvature than a port portion on a side upstream of the bent port portion. The bent port portion has a greater inner diameter than the inner diameter of the corresponding intake opening, whereby air can be inducted in a sufficient amount without deterioration to the directing function for air to be inducted into the combustion chamber.

Abstract: A stratified burning internal combustion engine according to this invention is equipped with an intake port and a fuel feed device so that stratified tumble flows of different fuel concentrations can be formed in a combustion chamber. An ignition device is provided in the combustion chamber to ignite at least one of the tumble flows, said at least one tumble flow being rich in fuel. To promote the stratified tumble flows, a top wall of a piston has an inclined wall. This makes it possible to strengthen the tumble flows, whereby the stratification of an air-fuel mixture in the combustion chamber can be improved further to permit lean burn at a larger air/fuel ratio.

Abstract: An engine intake system includes a primary port for introducing intake gas throughout an entire engine operating condition. A secondary port is provided with a gate valve which is opened in a high engine load condition for introducing the intake gas. A ratio of a tumble flow to a swirl flow is gradually increased as the gate valve is operated from an entirely closed condition to a fully open condition. According to this invention, ignition and combustion characteristics can be improved.

Abstract: A multivalve internal combustion engine which has a cluster valve system, said system comprises a cam on a camshaft, a valve stem with a valve spring, a cluster valve lever mounted on a lower end of said valve stem, said cluster valve lever has a plurality of holes and a plurality of valves. Said valves are inserted into said holes of said cluster valve lever respectively, and secured by mated nuts that are tightened by application of torque to make the cluster valve system to operate as one single valve.

Abstract: Several embodiments of internal combustion engines having at least five valves, three intake and two exhaust, all operated by a single camshaft. The intake valves are disposed so as to provide a smooth combustion chamber configuration by minimizing the difference in-angle between the valves and the valves and rocker arms are arranged so that different degree of lift may be provided. All of the intake valves have the same stem length. One rocker arm operates one valve and another rocker arm operates two valves with the two valves being operated being differently configured so as to provide the desired different lift. In addition, a staged intake system is included that has a single intake passage that extends perpendicular to a plane containing the cylinder bore axis and serving one intake valve and a siamese intake passage serving the other intake valves. The siamese intake passage has a section that extends also perpendicularly to the plane.

Abstract: A valve mechanism for an internal combustion engine with a four-valve, double-overhead camshaft (DOHC) valve train in which the axes of valves for each cylinder diverge outwardly from and are non-parallel with respect to the axis of the cylinder, the valve mechanism having a finger follower for each camshaft lobe and valve and with a contact pad between the cam and the finger follower to permit rocking movement so that the orientation of the finger follower and the axis of the valve remains at a fixed relationship.

Abstract: A fuel injection type internal combustion engine includes a cylinder head which is provided with a pair of intake valve bores facing a combustion chamber, a single intake passage, and a pair of intake ports between which a partition wall is interposed and which connect the intake passage and the intake valve bores to each other, and a fuel injection valve with a fuel ejection port disposed to be directed from the single intake passage toward the intake valve bores. Air assist ejection ports are disposed near the fuel ejection port for finely atomizing the fuel and are disposed at opposite sides of the fuel ejection port on a plane substantially including the fuel ejection port and that end edge of the partition wall which is closer to the intake passage, so that the air assist injection directions intersect each other and the fuel jet. This ensures that the fuel jet is narrowed in width at a portion corresponding to the partition wall by air flows from opposite sides, so that the entire fuel jet is flattened.

Abstract: A number of embodiments of inductions and fuel injection systems for internal combustion engines that improve exhaust emission control and fuel economy without adversely effecting the running of the engine under any running condition. This is accomplished by injecting fuel into one of at least two intake passages and providing exhaust gas recirculation into another of the intake passages. A stoichiometric fuel air mixture is introduced and the amount of exhaust gas recirculation is such that a minimum amount of air is inducted into the combustion chamber through the other intake passage when exhaust gas recirculation is being accomplished. Both two and three intake valve systems are disclosed and these use either control valves for controlling the flow through the other intake passages or operate without control valve.

Abstract: An actuator for controlling the flow of air through an air inlet port, particularly a secondary air inlet port, in an intake manifold in an internal combustion engine. The actuator actuates means disposed in the throat of the inlet port for opening and closing said port. The actuator comprises a housing, a reversible motor disposed in the housing, power transmission means with said motor comprising a non-planetary gear train disposed in the housing, and a shaft rotatably mounted in the housing operably engaged at one end thereof with the power transmission means and at its other end with the means for opening and closing the air inlet port.

Abstract: On a main rocker arm, there is arranged a pivotal sub-rocker arm. A rocker arm coupling mechanism is employed which, under a given condition of an associated engine, couples tightly the main rocker arm and the sub-rocker arm to cause the main rocker arm to pivot in accordance with rotation of a higher lift cam. First and second tappet members are carried by the main rocker arm to actuate two intake or exhaust valves of the engine in response to the pivoting movement of the main rocker arm. The second tappet member is loosely connected to the main rocker arm so that, under a certain condition, the second tappet member fails to transmit the pivoting movement of the main rocker arm to the associated valve. A tappet locking mechanism is further employed which, under a given operation condition of the engine, locks the second tappet member to the main rocker arm thereby to ensure the transmission of the pivoting movement of the main rocker arm to the associated valve.

Abstract: Several embodiments of internal combustion engines having at least five valves, three intake and two exhaust, all operated by a single camshaft. The intake valves are disposed so as to provide a smooth combustion chamber configuration by minimizing the difference in angle between the valves and the valves and rocker arms are arranged so that different degree of lift may be provided. All of the intake valves have the same stem length. One rocker arm operates one valve and another rocker arm operates two valves with the two valves being operated being differently configured so as to provide the desired different lift. In addition, a staged intake system is included that has a single intake passage that extends perpendicular to a plane containing the cylinder bore axis and serving one intake valve and a siamese intake passage serving the other intake valves. The siamese intake passage has a section that extends also perpendicularly to the plane.

Abstract: A gaseous fuel rotary piston engine has a rotor housing and a rotor. A side housing of the rotor housing is provided with an air intake port for supplying air to working chambers defined in the rotor housing and a gaseous fuel port which is connected to a gaseous fuel source through a fuel supply passage and through which gaseous fuel is supplied to the working chambers. The air intake port is formed to open near the top dead center on the intake stroke and close after the bottom dead center on the intake stroke. The gaseous fuel port is formed to open near the opening time of the air intake port and close substantially at the middle of the compression stroke.

Abstract: A four-stroke cycle internal-combustion engine having two large- and small-diameter intake valves and two large- and small-diameter exhaust valves in one cylinder and mounted with a valve-operating mechanism on either of the intake valve side and the exhaust valve side. Each valve-operating mechanism comprises a first valve-operating cam of a narrow total valve-opening angle and a low lift, a second valve-operating cam of a wide total valve-opening angle and a high lift, a rocker arm for the small-diameter valve in direct engagement with the first valve-operating cam, a rocker arm for the large-diameter valve, and a connecting means capable of simultaneously operatively connecting the second valve-operating cam with the rocker arm for the small-diameter valve and the rocker arm for the large-diameter valve. In each cylinder at least three spark plugs are mounted. The combustion chamber is formed high on one side and low on the other side.

Abstract: An adjustable valve gear is provided for two lift-type intake valves per cylinder in an internal combustion engine which are actuated by the cams of a camshaft via rocker arms with variable support and a rocker cam. In order to make possible different lift curves for the two lift-type intake valves, each lift type intake valve is assigned a separate rocker cam. At least one of the curve joints assigned to a lift-type intake valve and establishing the connections between a cam and a rocker arm, between the rocker arm and its support and between a rocker cam and the lift-type intake valve are configured with a different shape or a rotated installation position relative to a curve joint assigned to the other lift-type intake valve.

Abstract: A mechanical supercharger is provided in an intake manifold, and two inlet ports in communication with a cylinder are provided. A swirl control valve disposed in one of the two inlet ports is opened in a low speed/medium load region, and closed in a low speed/high load region and a low speed/low load region. Accordingly, scavenging performance can be enhanced in the low speed/medium load region where the pressure of a supercharged mixture flow is not sufficiently higher than the pressure of exhaust gas. In the low speed/high load region where the pressure of the supercharged mixture flow is sufficiently higher than the pressure of exhaust gas, undesired blowing of the mixture through a combustion chamber without being used for combustion can be suppressed while ensuring satisfactory scavenging, and an occurrence of knocking can be prevented.

Abstract: In a four-stroke cycle engine in which a combustion chamber is formed by a piston accommodated in a cylinder block and a cylinder head disposed in the cylinder block and respective two suction valves and two exhaust valves are disposed in the combustion chamber, the combustion chamber is divided into two combustion sections each in which one of the suction valves and one of the exhaust valves are disposed. A mixture in a theoretical air-fuel ratio is fed into one of the divided combustion sections and a mixture in an air-fuel ratio corresponding to an engine load is fed into another one of the divided combustion sections, and the air-fuel ratio being changed in response to the engine load. In a case where the mixture in an air-fuel ratio includes an exhaust gas, substantially the same operation is performed, but in this case, the degree of opening of an exhaust gas recirculation valve is controlled so as to control the air-fuel ratio of the mixture.

Abstract: Intake ports are arranged independently from each other between an injector and each combustion chamber and are formed in an inverted triangular cross-sectional shape, whereby intake fluids flow along upper walls of the corresponding ports and become a stratified tumble flow in the combustion chamber 10. One of the three ports, said one port being centrally located and opposing a spark plug, is used as an air-fuel intake port, while the remaining ports arranged on both sides of the port are employed as air intake ports. A fuel injector is provided to feed fuel only to the port. An air-fuel mixture drawn into the combustion chamber through the port flows as a tumble flow. This tumble flow is flanked by tumble flows of air drawn into the combustion chamber through the ports respectively, whereby tumble flows flow in the form of a three-layer tumble swirl as a whole.

Abstract: An engine comprising a fuel injector arranged on the inner wall of the cylinder in the vicinity of the intake valve. When the engine is operating under a heavy load, fuel is injected by the fuel injector during the intake stroke toward the rear face of the valve head of the intake valve. At this time, the injected fuel impinges upon the rear face of the valve head of the intake valve and is reflected thereon. Then, the injected fuel flows into the intake port.

Abstract: A method of phaseshifting a variable cycle engine utilizing the Otto cycle engine timing schedule for full-load and the Atkinson cycle engine timing schedule for part-load operation, the engine having multiple intake valves and an exhaust valve, phaseshifting of the intake and exhaust events coupled with adjustment of the clearance volume and the use of residual gas in the cylinder as a determinant of the intake charge volume and the compression end temperature level, to provide a high engine operating efficiency while concurrently lowering nitrogen oxide emissions and eliminating the need for an external exhaust gas recirculating system.

Abstract: An engine control system for controlling an internal combustion engine equipped with a mechanical supercharger includes a valve timing control mechanism which causes first and second intake valves for each cylinder to retard opening and closing of a first intake port with respect to opening and closing of a second intake port. Opening and closing of the first intake port is retarded when a specific range of engine operating conditions, in which the supercharger is operating, is detected.

Abstract: Several embodiments of internal combustion engines having at least five valves, three intake and two exhaust, all operated by a single camshaft. The intake valves are disposed so as to provide a smooth combustion chamber configuration by minimizing the difference in angle between the valves and the valves and rocker arms are arranged so that different degree of lift may be provided. One rocker arm operates one valve and another rocker arm operates two valves with the two valves being operated being differently configured so as to provide the desired different lift. In addition, a staged intake system is included that has a single intake passage that extends perpendicular to a plane containing the cylinder bore axis and serving one intake valve and a siamese intake passage serving the other intake valves. The siamese intake passage has a section that extends also perpendicularly to the plane.

Abstract: The invention relates to an internal combustion engine comprising an inlet manifold, at least one combustion chamber with at least two inlet valves and at least one outlet valve, a piston reciprocable in the or each chamber to define a variable volume space therein, and means for controlling the timing of the opening and closing of each of two of the inlet valves of the or each chamber independently so that opening of one of the independently controlled inlet valves of the or each chamber occurs during the exhaust stroke of the engine, opening of the other of the independently controlled inlet valves of the or each chamber, at a time when said one of the independently controlled inlet valves is closed, and when pressure in the or each chamber is lower than pressure in said inlet manifold, producing a predetermined pressure differential across said other of the independently controlled inlet valves, creating an in-flow to the or each chamber generating turbulence, at least some of which is present when combust

Abstract: In a dual-fuel internal combustion engine which can selectively use gaseous fuel such as CNG or liquid fuel such as gasoline, a pair of intake passages are independently connected to a combustion chamber of the engine, and a gaseous fuel supply device and a liquid fuel supply device are provided in the corresponding intake passages so that the liquid and gaseous fuels may not mix with each other when the fuel for the engine is switched over one from the other as they are introduced into the combustion chamber through different intake passages. Further, by switching the operating mode of the intake valve when changing the fuel, the configuration of the intake passage can be optimized for each fuel, and the timing and the lift of the intake valves may also be optimized for each fuel without complicating the control structure of the overall system. The present invention can improve the torque output and the emission property of the dual-fuel engine.

Abstract: A fuel injector of the type in which a valve hole is opened and closed by a valve so as to intermittently inject pressurized fuel from the valve hole includes a distributing adapter fixedly attached to a front end of the valve hole, and an air adapter fixedly attached to a front end of the distributing adapter. The air adapter is formed with a plurality of guide holes directed to a plurality of intake ports of the engine, respectively, and assist air passages each communicating laterally with a corresponding one of the guide holes. The distributing adapter is formed with distributing holes of the same number as the guide holes, each of the distributing holes extending between the valve hole and a corresponding one of the guide holes.

Abstract: A fuel feed apparatus of an internal combustion engine comprises: a passage member which is formed with a fuel passage serving to direct fuel injected from a fuel injection valve toward respective intake valves of the internal combustion engine, assist air passage through which assist air is jetted so as to cross the fuel injected from the fuel passage, and a cylindrical guide portion serving to regulate a spray cone angle of the fuel when the assist air is jetted from the assist air passages; and an interrupter device for interrupting the supply of the assist air to the air assist passages in accordance with the operating condition of the internal combustion engine, so that sprays of fuel directed to the plurality of intake valves individually are formed by the fuel passage when the interrupter device cuts off the assist air, while a single spray of fuel atomized by the assist air the spray cone angle of which is regulated by the guide portion is formed when the interrupter device allows the assist air to be

Abstract: In an internal combustion engine comprising a valve operating system connected to a pair of intake valves and arranged to open one of the intake valves only in a very small amount such that the one intake valve is brought into its substantially inoperative state, in a suction stroke mainly in a low speed rotation region of the engine, a fuel injection valve capable of injecting fuel toward a pair of intake ports independently corresponding to the intake valves, and a control means for controlling the operation of the fuel injection valve, the control means is arranged to control the fuel injection valve with a fuel injection completion time determined within a suction stroke, when the one intake valve is in the substantially inoperative state.

Abstract: A valve operating system in an overhead cam type multicylinder internal combustion engine having three intake-side rocker arms disposed to operate a pair of intake valves and two exhaust-side rocker arms disposed to operate a pair of exhaust valves. The intake-side rocker arms are provided with a connection switchover mechanism capable of switching-over the connection and disconnection of the adjacent in take-side rocker arms. Exhaust-side cams are provided on a cam shaft on opposite sides of intake-side cams which are provided adjacent one another. Two of the intake-side rocker arms and both of the exhaust-side rocker arms are in rolling contact with the corresponding cams through rollers mounted on the rocker arms. The exhaust-side a rocker arms are provided with notches in the area near the cam shaft for accommodating portions of the intake-side rocker arms, respectively.

Abstract: An air intake system for a fuel injected type of motorcycle engine wherein the induction system for the engine is such that it along with the engine substantially encloses a fuel injector so as to silence any noise emanating from it.

Abstract: Multiple intake valves operatively associated in a common combustion chamber are advantageous in that the design achieves high output for an internal combustion engine. The subject modified cylinder head utilizes the advantages available in a multiple intake valve system, but further enhances the design by reducing heat rejection. In the subject modified cylinder head, three intake valves (38,40,42) having corresponding intake valve ports (26,28,30) and one exhaust valve (68) having an exhaust valve port (66) are operatively associated in a common combustion chamber. A reduction in heat rejection is achieved through a relationship between the cross-sectional areas of the intake and exhaust valve ports (26,28,30,66). The intake valve ports (26,28,30) are constructed so that their cross-sectional area is larger than about 69% of the combined cross-sectional area of the intake and the exhaust ports (26,28,30,66).

Abstract: A motorcycle powered by a fuel injected four cycle internal combustion engine having three valves per cylinder served by a Siamese type intake port arrangement. The centers of the inlet openings of the intake ports are offset from the center of the center intake port served thereby and a single fuel injector is disposed for spraying fuel into each of the intake openings so that all ports will receive equal amounts of fuel and so that the fuel injectors are disposed in parallel relationship to permit a single fuel rail to supply fuel to all of the fuel injectors.

Abstract: In a two-stroke internal combustion engine with a compression-ignition of Diesel type, the exhaust valve or valves (10) are so arranged as to allow flow on at least the major part of their periphery; the piston (3) cooperates with the ceiling of the cylinder head (6) in such manner as to leave, in the vicinity of top dead center, only the required operational clearance between the piston (3) and the part of the ceiling of the cylinder head in which the exhaust valve or valves (10) is or are placed; and a cylindrical recess (14) in which is placed the head (13) of the inlet valve or valves (8) and into which a fuel injector discharges, is arranged in such manner as to constitute practically alone the combustion chamber (7) when the piston (3) is in the vicinity of top dead center.

Abstract: A number of embodiments of these valve intake systems for internal combustion engines served by a siamese type intake passage and configured to generate a swirl in the intake charge. A single fuel injector sprays fuel into a common inlet opening of the siamese intake passage and sprays more fuel toward the swirl side port so as to insure equal flow through all of the ports.

Abstract: A cylinder head intake porting system for a three intake valve internal combustion engine wherein a staged induction system is employed and mid-range torque is improved by communicating separate intake passages with each other. Both carbureted and fuel injected embodiments are shown.