Abstract: Methods and systems are provided for adjusting multiplexed ignition signals in an engine system based on engine operating conditions, each cylinder of the engine system including a main chamber spark plug and a pre-chamber system. In one example, a method may include multiplexing spark signals to a first spark plug, a second spark plug, a third spark plug, and a fourth spark plug, the first spark plug coupled to a pre-chamber of a first cylinder, the second spark plug coupled to a pre-chamber of a second cylinder, the third spark plug coupled to a main chamber of the first cylinder, and the fourth spark plug coupled to the main chamber of the second cylinder. In this way, one ignition coil may be used to actuate two different spark plugs coupled to separate cylinders.

Abstract: The present invention relates to an internal-combustion engine comprising a combustion chamber provided with a single intake valve (2), a single exhaust valve (3), two plugs (4a, 4b) and a fuel injector (5). Furthermore, the combustion chamber comprises means for forming an aerodynamic swirling motion structure of the intake gas in the combustion chamber. Besides, fuel injector (5) is oriented so as to inject the fuel into the central area of the combustion chamber in the direction of the aerodynamic swirling motion structure.

Abstract: A spark plug, including a metallic shell, an insulator, a center electrode, and a ground electrode. The insulator includes a first outer surface at least partly along an exposed portion and a second outer surface at least partly along an unexposed portion. The first outer surface extends between the exposed-unexposed interface to a tip merge portion adjacent a distal end of the insulator. The first outer surface and the second outer surface meet at a nose surface transition. At the nose surface transition, the first outer surface is disposed at a first angle with respect to a central axis of the spark plug, and the second outer surface is disposed at a second angle with respect to the central axis of the spark plug. The first angle is larger than the second angle, and the nose surface transition is located within the unexposed portion or at the exposed-unexposed interface.

Abstract: A water cooled engine is provided, including a cylinder head with minimized thermal strain. A head water jacket includes an inter-exhaust-port-wall water channel between a first exhaust entrance port wall and a second exhaust entrance port wall. The cylinder head includes a cooling water injection passage provided at a bottom wall thereof. The cooling water injection passage is positioned on the exhaust end side, and includes a passage entrance provided on the exhaust end side, and a passage exit directed toward the inter-exhaust-port-wall water channel. An exhaust port wall includes a heat dissipation fin extending from a first exhaust entrance port wall toward an exhaust end. The space between the heat dissipation fin and a second exhaust entrance port wall forms a water channel entrance of the inter-exhaust-port-wall water channel.

Abstract: A plasma header gasket for use with an internal combustion engine includes electrodes disposed around the perimeter of apertures in the gasket corresponding to piston cylinders in the engine. The electrodes produce a plasma spark in time with the engine to increase the efficiency of combustion. The plasma spark produces an ignition discharge compatible with various types of engines and types of fuels.

Abstract: A method and system to verify active content at a server system include receiving, at the server system a communication (e.g., an e-mail message or e-commerce listing) that includes active content that is to be made accessible via the server system. At the server system, the active content is rendered to generate rendered active content. The rendered active content presents a representation of information and processes to which an end user will be subject. At the server system, the rendered active content is verified as not being malicious.

Abstract: Systems and methods for self-testing archival memory devices are described. The memory device includes a data storage component capable of being coded with data. The memory device further includes a read-write mechanism configured to read, write, and delete data stored on the data storage component. The memory device includes a read-write controller configured to control the read-write mechanism based on input received through a device interface of the memory device, wherein the device interface of the memory device is configured to connect to an external computing device. The memory device further includes a diagnostic controller configured to perform a test on at least one of the data stored on the data storage component, the data storage component, and the read-write mechanism. The memory device includes a power source configured to provide operational power to the diagnostic controller when the memory device is not connected to an external power source.

Abstract: An ignition control device for an engine provided with ignition plugs for each cylinder. The ignition control device includes a sensor that detects a signal that determines whether the engine is in an idling state or not, and an ignition control unit that determines whether the engine is in the idling state on the basis of a signal from the sensor and controls the ignition plugs to be simultaneously ignited if the engine is in the idling state, and controls part of the ignition plugs to be ignited if the engine is in a state other than the idling state.

Abstract: The invention relates to an interface part (10) between a motor vehicle engine head and a heat exchanger (12), the interface part (10) comprising a first opening for the flow of a first gas. According to the invention, the first opening has a profile capable of engaging with a valve element comprising a movable portion (52) of the valve (50), with a view to at least partially sealing the first opening by means of said movable portion (52). The invention also relates to an assembly of such an interface part and a valve, and to a gas supply module for an engine comprising such an assembly. The invention is applicable, in particular, to the automotive field.

Abstract: The sparking gasket amalgamates two traditional parts of the internal combustion engine into one unit by replacing the spark plug with electrode circuitry embedded into the gasket material. This system provides reduced hydrocarbon emissions by improving combustion thus giving a cleaner burn with increased fuel economy and improved engine performance. The new materials being used have greatly increased gasket life by reducing material deterioration and insulation breakdown that lead to engine failure. Further improvements in electrode design, materials and positioning have led to improved efficiency gains. In this design the electrode circuitry is fused between two material wafers thus encapsulating it in one solid bonded unit.

Abstract: A bottom face of a cylinder head (3) defining a combustion chamber (1) is formed substantially in a shape of a spherical shell, and ignition points (21) are arranged in three or more on a concentric circle of 55 to 70% of a diameter of a cylinder block (30) or the vicinity thereof, and combustion is performed with an air excess ratio of the combustion chamber (1) of 1.5 or more.

Abstract: A system and method for operating an engine having at least two spark plugs per cylinder include controlling at least one actuator to alter combustion within a selected cylinder such that the combustion burn rate determined by ion sense current signals associated with the at least two spark plugs of the selected cylinder approaches a desired combustion burn rate. A desired combustion burn rate is determined based on current engine/vehicle operating and ambient conditions with ion sense signals from each spark plug analyzed to determine combustion timing relative to corresponding ignition timing. Ignition timing and/or other actuators are controlled in response to provide a desired combustion burn rate.

Abstract: Disclosed is an upper structure of an engine having three or more cylinders arranged in a row. A first one of a pair of adjacent cylinders among at least three of the cylinders serially arranged in a cylinder row direction is provided with a second spark plug at a position on an opposite side of a second one of the pair of adjacent cylinders, and the second one of the pair of adjacent cylinders is provided with a second spark plug at a position on an opposite side of the first one of the pair of adjacent cylinders. The present invention can provide enhanced flexibility in design of a head cover of the engine.

Abstract: This invention describes how a blend of silicon polymers, mixed with the right combination of fillers applied to fiber reinforcement laminated with an embedded circuit and laser cut into vacuum formable preforms enables the production of “red heat” durable flexible ceramic multiple spark ignition devices which are vacuum formed into the head combustion chamber of IC engines for realizing fuel savings from up to 33% increased combustion efficiency. The MSI device also comprises a spark plug which is made with the steel adjustable grounding gap section removed. The spark plug electrode alignment for the fuel injectors is also used to align the spark plug electrode to insert during assembly into the MSI device (see FIG. 1) circuit port. This electrode insertion enables the electrode to arc within the 360° gap of the circuit port setting off the “in series” arcing of the two other electrodes within the surround combustion circuit completing the drop in potential at the ground attachment (see FIG. 1).

Abstract: A two-stroke internal combustion engine which has an Inverted Cross-Scavenged operation forming a 180° air and exhaust gas loop and having two overhead valves [46, 47] in the cylinder head and optimized coils [43, 44] per spark plug [41, 42], the spark plugs being halo-disc type plugs, a central fuel-injector means [45], and the combustion chamber forming a Perfect Miller Cycle with an effective CR of approximately 10.5 to 1 and ER equal to approximately 18 to 1, and the valves opening at near bottom center (BC) and closing at approximately 75° after BC, and a quick response super-charger or turbo-charger located at the intake.

Abstract: An engine system includes two spark plugs in a cylinder of an engine. The two spark plugs have different heat ranges in order to address pre-ignition, where only a first spark plug operates during a first condition, and only a second spark plug operates during a second condition.

Abstract: An internal combustion engine is described herein. The engine may include a combustion chamber having a pair of intake ports arranged at one side, and an exhaust port arranged at the other side. The engine may also include a fuel injector configured to inject fuel into said combustion chamber from a side of said intake ports toward a side of said exhaust port, a variable flow restrictor capable of making flow resistance of said second intake port greater than flow resistance of said first intake port, a first spark plug arranged on a ceiling of the chamber and having its spark gap in the proximity of a center portion of said ceiling, and a second spark plug arranged on said ceiling and having its spark gap which is positioned closer to said first intake port in the axial direction of said crankshaft than said first spark plug.

Abstract: A method of operating an internal combustion engine having at least one combustion chamber including a first spark plug and a second spark plug, wherein the first spark plug is configured to operate at a higher temperature than the second spark plug, the method comprising of varying at least a resulting ratio of an amount of a fuel and an amount of a fluid delivered to the combustion chamber responsive to a first condition, and selectively using at least one of the first spark plug and the second spark plug to ignite at least one of the fuel and the fluid delivered to the combustion chamber.

Abstract: A system and method for operating a multiple cylinder internal combustion engine having at least two spark plugs per cylinder include selectively isolating all but one spark plug associated with the cylinder at least during an ionization current sensing period to reduce or eliminate interference among ionization current signals flowing through more than one spark plug.

Abstract: An ignition control apparatus for an engine; in particular, an engine having two or more igniter plugs per cylinder energized by a electric power source, comprises a voltage detector for detecting a voltage of the electric power source, and a controller configured to effect initial combustion using both igniter plugs, to determine whether the voltage is lower than a first threshold voltage, and to effect further combustion using one of the igniter plugs when the voltage detected by the voltage detector is determined to be lower than the first threshold voltage.

Abstract: An internal combustion engine 10 has a cylinder head 11 slideably supporting one or more poppet valves 30. At least a portion of one of the poppet valves 30 in each combustion chamber of the engine 10 forms in combination with one or more secondary electrodes 35, 133, 233, 333, 433 a number of electrode pairs between each of which an electrical discharge is selectively caused to flow so as to initiate combustion in the respective combustion chamber. The electrode pairs may be formed at differing locations within each combustion chamber so as to improve combustion efficiency.

Abstract: A plurality of electrode pairs (P1 to P8) are caused to project from a side wall of a combustion chamber (2) of an engine, and a distance between ignition gaps (G1 to G8) and the side wall of the combustion chamber (2) is varied according to the positions of the plurality of electrode pairs (P1 to P8).

Abstract: An internal-combustion engine is disclosed in which a pair of inlet valves and a pair of outlet valves are provided within the combustion chamber formed in each of a row of cylinders. A first ignition plug is disposed in the cylinder head within a central area of the combustion chamber in plan view. Second and third ignition plugs are disposed in the cylinder head at opposite peripheral portions of the combustion chamber positioned approximately along the first axis direction in plan view, the second and third ignition plugs are arranged so that the discharge electrode portions of the second and third ignition plugs being inclined inwardly of the combustion chamber in opposite directions and are substantially symmetrical relative with the first ignition plug in plan view. A line intersecting the discharge electrode portions of the second and third ignition plugs forms an oblique angle with the direction of the row of cylinders in plan view.

Abstract: A multipoint ignition device comprises: a head gasket (1) interposed between a cylinder head and a cylinder block of an engine, having an opening (3) in a position corresponding to a cylinder opening portion; and a plurality of intermediate members (6) connected respectively to a plurality of electrode pairs (2) and held by the head gasket (1). A part of at least one of the plurality of intermediate members (6) is exposed to the opening (3).

Abstract: A multipoint ignition device comprises: a head gasket (1) interposed between a cylinder head and a cylinder block of an engine, having an opening (3) in a position corresponding to a cylinder opening portion; and a plurality of intermediate members (6) connected respectively to a plurality of electrode pairs (2) and held in the head gasket (1). Respective heat values of the plurality of electrode pairs (2) are set individually by varying the contact area between the plurality of intermediate members (6) and the head gasket (1) according to the respective disposal positions of the plurality of intermediate members (6).

Abstract: Respective heat values of a plurality of electrode pairs P1 to P8 are set individually such that the temperatures of all of the plurality of electrode pairs (P1 to P8) are kept within an appropriate temperature range in which a temperature no lower than a self-cleaning temperature is set as a lower limit temperature and a lower temperature than a pre-ignition temperature is set as an upper limit temperature.

Abstract: When a homogeneous combustion is to be executed at a lean air-fuel ratio, a tumbling flow that whirls in the cylinder descending in the cylinder bore on the exhaust valve side and ascending in the cylinder bore on the intake valve side, is intensified by the fuel that is injected from the fuel injection valve toward the exhaust valve side in the cylinder bore in the last stage of the intake stroke.

Abstract: The present invention provides an intake port design that provides a low thermal inertia characteristic, thereby decoupling the surface temperature of the intake port walls from that of the coolant through use of an air gap formed between the intake port and the cylinder head. At idle and part-throttle, the intake port is at a higher surface temperature yielding better cold-start emissions, better mixture preparation, and less dense intake charge (“thermal throttling”) for better fuel economy. At wide-open-throttle, the intake port is at a lower surface temperature yielding better volumetric efficiency for improved torque and reduction in knocking tendency enabling higher compression ratio for improved fuel economy and performance. The intake port design of the present invention can be manufactured with a hydroform manufacturing process resulting in improved dimensional consistency and smooth surface finish. Additionally, the process eliminates some cylinder head machining processes.

Abstract: This invention relates to a combustion chamber structure for a spark-ignition engine, which comprises a combustion chamber defined between a bottom surface of a cylinder head and a top surface of a piston in such a manner that the bottom surface of the cylinder head serves as a ceiling wall thereof, and a spark plug having a sparking end protruding from the ceiling wall into the combustion chamber. In this combustion chamber structure, when the piston is at a top dead center, a principal space of the combustion chamber is comprised of a first combustion space around the sparking end of the spark plug and a second combustion space around a circumference of a cylinder bore. Further, the first combustion space and the second combustion space are communicated with each other through a small interspace zone where an interspace between the ceiling wall and the top surface of the piston is narrowed. The combustion chamber structure makes it possible to increase compression ratio in a practically effective manner.

Abstract: An embedded igniter for internal combustion engines consisting of a multiple ignition system with separate control for individual pairs of igniters that has been designed to replaces the spark plugs of internal combustion engines. This device allows for a more complete burn of the fuel/air mixture within the combustion chamber. The embedded igniter system will consist of one or more igniter units consisting of a pair of rectangular tantalum bars with iridium electrode pins at the ends. The paired igniter pins are encased in alumina ceramic, a high dielectric/high temperature housing positioned around the combustion chamber holding and insulating the electrodes relative to their position in reference to the combustion chamber. One or more igniter units may be incorporated around each cylinder opening of a head gasket made from a composite of polyamide, carbon fiber and copper or equivalent material or may be incorporated into an internal combustion engine that does not require a head gasket.

Abstract: A multipoint ignition engine (1) includes a central electrode pair (9), disposed in the center of a combustion chamber (2), for forming a central spark gap (10), and a plurality of peripheral electrode pairs (12) held in a head gasket (15), which has an opening portion having a substantially identical diameter to an opening portion of a cylinder (5) in a position corresponding to the opening portion of the cylinder (5), for forming a plurality of peripheral spark gaps (13) around the inner periphery of the opening portion in the cylinder (5). An air-fuel mixture in the combustion chamber (2), which is obtained by mixing together fuel and air evenly to the stoichiometric air-fuel ratio or a richer/leaner air-fuel ratio than the stoichiometric air-fuel ratio, is ignited using both the central spark gap (10) and the plurality of peripheral spark gaps (13).

Abstract: A spark plug system includes a center spark plug and a plurality of peripheral spark plugs, the spark plugs extending into a ridge-roof type combustion chamber of an internal combustion engine from the inner surface of a cylinder head and being disposed approximately on the ridgeline of the ridge-roof. The amount by which the center plug projects into the combustion chamber from the inner surface of the cylinder head is different from the amount by which each of the peripheral plugs projects into the combustion chamber from the inner surface of the cylinder head, whereby the time in which the flame propagation of the center plug reaches the flame propagation of the peripheral plugs is delayed.

Abstract: An internal combustion engine that includes a cylinder block formed with a cylinder bore, a cylinder head operatively connected to the cylinder block; a piston slidably disposed in the cylinder bore to define a combustion chamber; an engine front side squish area and a rear side squish area where the engine front and rear side squish areas include narrow gaps formed between a cylinder head and the piston is disclosed. The engine front side squish area and the engine rear side squish area generate a squish flow in the combustion chamber in response to the piston moving within the cylinder bore. Engine front and rear side igniter plugs are also provided that each include a pair of electrodes placed adjacent the respective engine front and rear side squish areas so that squish flow may pass through an igniter gap defined between the pairs of electrodes of the front and rear side igniter plugs.

Abstract: An improved ignition-engine system for internal combustion engines comprising a compact combustion chamber in the cylinder head and two main squish zones (101a, 101b) for producing high flow and turbulence, and at least one minor squish zone (105) at the end of the intake valve (104), the system using independently operated spark plugs (102a, 102b), placed asymmetrically at or near the edge of the high flow squish zones to handle both ultra-lean light load conditions and high load conditions without misfire or knocking, the engine leanness and high load operation and further improved by using variable compression ratio and/or direct fuel injection, including air-blast fuel injectors (181) and more centrally located air-blast-ignition fuel injector (193) more ideally suited for four valve engines and mild hybrid engines.

Abstract: An SOHC-type engine in which first and second insertion/removal guide sections for guiding the insertion and removal of first and second spark plugs, respectively, are provided on a cylinder head including an intake valve and the first spark plug disposed therein and arranged along an axis of a camshaft, and an exhaust valve and the second spark plug disposed therein and arranged along the axis of the camshaft.

Abstract: An in-cylinder injection type internal combustion engine is provided, which first fires a first spark plug and thereafter fires a second spark plug when a required load is low and which first fires the second spark plug and thereafter fires the first spark plug when the required load is high.

Abstract: A fuel supply and injection system includes a fuel tank, a single electric pump unit, a plurality of fuel injection valves and a piping arrangement. The pump unit is provided in the fuel tank and includes an inlet for taking the fuel in the fuel tank and an outlet for discharging the fuel. The injection valves are secured to an engine main body. Each fuel injection valve includes a nozzle, which is disposed in a corresponding one of combustion chambers and injects the fuel supplied from the pump unit directly into the corresponding one of the combustion chambers. The piping arrangement connects between the electric pump unit and each fuel injection valve. The pump unit is the only pump for supplying the fuel to the fuel injection valves.

Abstract: A valve train is disclosed for an internal combustion engine having a block, a camshaft in the block, and at least two push rods actuated by the camshaft. The valve train comprises first and second rockers, and three valves. The first rocker is actuated by one of the push rods, and the second rocker is actuated by another of the push rods. A first valve is associated with a cylinder of the engine and actuated by the first rocker. A second valve is associated with the cylinder and actuated by the first rocker, and a third valve is associated with the cylinder and actuated by the second rocker.

Abstract: In internal combustion engines having direct injection, an injector injects fuel into the combustion chamber to form an ignitable fuel/air mixture with combustion air supplied separately, the mixture being ignitable by a spark plug. The fuel is injected in a conical pattern, and the electrodes are protected from wetting by fuel and from coking if they are located outside the lateral surface of the fuel cone produced by the injection nozzle. To introduce an ignitable mixture between the electrodes and to ensure optimum operating performance of the internal combustion engine by improving the combustion process, a combustion chamber is configured so that the fuel cone is injected in a free jet which is substantially completely unaffected by the combustion chamber perimeter, and the electrodes of the spark plug project into a fuel vortex emerging from the lateral surface during injection.

Abstract: The invention comprises at least two independent intake ports 14a, 14b connected to a combustion chamber 15, two intake valves 12a, 12b, and two exhaust valves 13a, 13b. Upper and lower channels 22a, 22b which are defined by a partition wall, and an intake control valve 25 for opening and closing the lower side channel 22b are provided in the interior of the first intake port 14a. An intake control valve 26 for opening and closing the first intake port 14b is also provided. The invention further comprises a controller 50 for controlling the opening and closing of the intake control valves 25 and 26, and the degree of opening of these intake control valves 25 and 26 is controlled in accordance with the operating conditions.

Abstract: An apparatus and method for the creation, placement and control of an area of electrical ionization within an internal combustion engine combustion chamber. This area of electrical ionization is positioned so that all of the fuel being injected into the combustion chamber must pass next to or through the area of electrical ionization to ensure that combustion has been initiated for all of the fuel as it is injected. This area of electrical ionization can be kept on as long as it is necessary to insure that the all of the fuel that is injected into the combustion chamber can be completely combusted. An engine equipped with this electrical ionization device has its fuel economy enhanced by timely, controlled, and complete combustion of all of the fuel injected into its combustion chamber. Furthermore, the pollutant emissions of both oxides of nitrogen and unburned hydrocarbons are reduced dramatically.

Abstract: A four-stroke reciprocating-piston internal combustion engine includes a fuel injection device, which is arranged centrally in a combustion space and which introduces the fuel in the form of an injection cone into the combustion space, and includes at least one spark plug for each combustion space, the electrodes of which spark plug are arranged at the edge of the injection cone. At least two spark plugs are provided, of which the second spark plug has a markedly higher spark gap than the first spark plug.

Abstract: The invention comprises at least two independent intake ports 14a, 14b connected to a combustion chamber 15, two intake valves 12a, 12b, and two exhaust valves 13a, 13b. Upper and lower channels 22a, 22b which are defined by a partition wall, and an intake control valve 25 for opening and closing the lower side channel 22b are provided in the interior of the first intake port 14a. An intake control valve 26 for opening and closing the first intake port 14b is also provided. The invention further comprises a controller 50 for controlling the opening and closing of the intake control valves 25 and 26, and the degree of opening of these intake control valves 25 and 26 is controlled in accordance with the operating conditions.

Abstract: In multi-cylinder engine in which an intake valve and a first spark plug arranged side by side along an axis of a camshaft and an exhaust valve and a second spark plug arranged side by side along the axis of the camshaft are disposed in a cylinder head for every combustion chamber, the position of a central portion of an upstream end of an intake port provided in the cylinder head with the intake valve interposed between the intake port and each of the combustion chambers and the position of a central portion of a downstream end of an exhaust port provided in the cylinder head with the exhaust valve interposed between the exhaust port and each of the combustion chambers are set to correspond with each other in the direction along the axis of the camshaft. Thus, the length of the cylinder head is reduced.

Abstract: The present invention related generally to a method for determining spark plug malfunction and more particularly to a method for determining spark plug malfunction in an internal combustion engine in which at least two spark plugs are disposed in each cylinder. In a dual plug configuration, a spark plug malfunction is detected by disabling one of the spark plugs during a test period in a particular cylinder. A misfire provides an indication of malfunction of the other spark plug.

Abstract: Secondary air is strategically introduced into a combustion chamber of an internal combustion engine event after the main combustion event to reduce HC and CO emissions. While the technique is applicable to virtually any otto cycle engine, it is particularly well-suited for use in a “rich burn” utility engine typically operating at an equivalence ratio (ER) of about 1.2 or above. Such engines start easily, run well, and emit low levels of NOx at ERs on the order of 1.2. The invention takes advantage of these benefits by admitting an air/fuel charge and allowing otto-cycle combustion to occur in at least generally the usual fashion (although at least preferably as rapidly as possible for a given engine design), using the standard fuel-rich carburetor calibration to fuel the engine.

Abstract: An ignition system for an internal combustion engine. At least one of a plurality of spark plugs 4 and 5 attached to each of cylinders 2A, 2B, 3B, and 3A is a self-cleaning spark plug A.

Abstract: In a set of heads for the cylinders of internal combustion engines with desmodromic valve operation, each head comprises an assembly of one or two inlet valves, and an assembly of one or two exhaust valves, so as to form heads with two, three and four valves. The assembly of inlet valves is positioned at an angle to the assembly of exhaust valves. The two assemblies are actuated through respective rockers by a single camshaft located substantially along the line running centrally between the two assemblies. The inlet duct and the exhaust duct are located in the same position within the head and have the same connections to the induction and exhaust systems in all the two-, three- and four-valve versions.

Abstract: An internal combustion aircraft engine comprising a cylinder head having a cylindrical head bore formed therein, a piston, and spark plugs, the cylinder head bore and piston designed to reduce engine knock. The cylinder head is fixedly attached to a top end of a cylinder barrel formed with cylindrical walls, the cylinder head bore and the cylindrical walls defining a cylinder. The cylinder head bore has formed therein an outwardly protruding cavity with respect to the top end of the cylinder barrel. The piston has a piston crown, and the piston contained within the cylinder, the piston crown, the cylinder walls, and the cylinder head bore define a combustion chamber. The piston crown has a concavity formed therein, and the piston is constructed and arranged to reciprocate within the cylinder. The concavity of the piston crown and the cavity cooperate at a top dead center position of the piston to form a swirl chamber.

Abstract: A cylinder injection engine includes a fuel injector for injecting a fuel into a combustion chamber formed between a cylinder head and a piston, an intake port opening to the combustion chamber, an intake valve disposed in the intake port, a plurality of spark plugs provided for each cylinder for effecting ignition of a mixture formed within the combustion chamber, an external EGR valve having a function of EGR amount control to the cylinder, and a gas flow control valve. The engine has air/fuel ratio mode setting and ignition mode setting.