Abstract: A valve actuating arrangement for a multiple valve engine wherein the valves are positioned so that they have their heads lying at different distances from the axis of rotation of the actuating camshaft. The valve stems are kept at the same length by employing cam lobes for actuating those that have different base circles.

Abstract: Variable swirl intake apparatus (24) controls a swirl of intake air in cylinder chamber (22) of an engine.

Abstract: An induction system for an internal combustion engine that has, in addition to the conventional main intake passage, a relatively small cross-sectional auxiliary intake passage which discharges into the main intake passage upstream of the point of communication of the main intake passage with the engine chamber and downstream of the throttle valve of the engine. A relatively large capacity plenum chamber feeds the auxiliary intake passage so that on the intake cycle a high velocity charge will be delivered from the auxiliary intake passage into the chamber to increase turbulence and improve the combustion efficiency.

Abstract: An internal combustion engine for a vehicle comprising three intake ports for each combustion chamber, three intake valves for opening and closing the intake ports, and an intake passage connected to the combustion chamber through the three intake ports, the lower-course region of the intake passage on the intake-port side being divided into three separate branch intake passages leading to the individual intake ports. The internal combustion engine according to the present invention further comprises a fuel injection valve disposed on the upper-course side of the branch intake passages of the intake passage, the injection valve having three jets through which atomized fuel flows of substantially equal quantities are injected toward their corresponding branch intake passages.

Abstract: In order to prevent the electrodes of the spark plug from becoming wetted with droplets of liquid fuel during low temperature and/or idling operation of the engine in a manner which deteriorates engine stability, the branches of a bifurcate intake passage which cooperates with a dual inlet valve arrangement are arranged to guide the unvaporized liquid fuel into the combustion chamber in a manner which obivates contact with the plug. In some embodiments a passage which is adapted to produce a swirl in the combustion chamber is arranged so that the fuel which passes therethrough (usually in the form of a film on the walls of branches) and which has a relatively large inertia as compared with the gaseous charge, enters the combustion chamber with a velocity which carries it along a flight path non-intersective with the plug electrodes.

Abstract: An internal combustion engine having two intake valves arranged in respective intake passages for each cylinder, wherein, a first intake passage is arranged to cause a swirl of intake air in the combustion chamber and a fuel injector is arranged in this intake passage, and a flow control valve is arranged in the second intake passage to close same when the engine load is low. An EGR passage is provided with an outlet in the second intake passage at a position between the second intake valve and the flow control valve, and the EGR gas is thus delivered to a volume enclosed in the second intake passage between the second intake valve and the flow control valve and remains there while these valves are closed. Then, when the second intake valve is open, the EGR gas slowly flows into the combustion chamber and floats toward and is collected at the upper region in the combustion chamber, while fuel flows smoothly into the combustion chamber, together with intake air, through the first intake passage.

Abstract: An intake system for internal combustion engines, comprising suction pipes of different lengths, which can be connected individually--preferably in accordance with the engine speed--to the intake passage in the cylinder head leading to the intake valve. The main intake pipe is connected to each intake passage by means of a connecting piece, and three suction passages of different lengths departing from the main intake pipe open into this connecting piece either in the direction of its axis or on opposite sides thereof, the connecting piece containing a butterfly control valve which is centrally mounted on a shaft parallel to the longitudinal axis of the engine, and which--in its two extreme positions and in its center position--establishes the flow connection between one of the suction passages and the intake passage.

Abstract: An internal combustion engine is designed to run on natural gas and utilize the diesel cycle. To promote combustion, a mixing chamber is dispersed within a combustion chamber formed between the piston and cylinder. The chamber includes a pair of concentric housings, the innermost of which receives fuel from the injector and provides a rich mixture in the volume between the housings.

Abstract: Variable swirl intake apparatus 24 controls a swirl of intake air in cylinder chamber 22 of an engine. Variable swirl intake apparatus 24 has intake port 25 which has entrance portion 25a formed on cylinder head 23 of the engine and extending from the side surface of cylinder head 23 and swirl chamber 25b which communicates with entrance portion 25a and is formed to provide a swirl to a gas flow flowing from entrance portion 25a, intake valve 26, arranged on the lower surface of cylinder head 23, for opening/closing between swirl chamber 25b and cylinder chamber 22 of the engine, swirl control path 28, one end of which is open to swirl chamber 25a on the side of entrance portion 25a with respect to a line connecting the axis along a piston sliding direction at the center of cylinder chamber 22 and the axis of the intake valve, and the other end of which is open to the side surface of cylinder head 23, and a control apparatus 29 for controlling a gas flow into swirl control path 28.

Abstract: An engine with a cylinder inlet port controlled by a poppet valve has a flow directing vane on a shaft aligned with the valve stem upstream in the direction of flow. The vane is movable between a position aligned with the valve stem in which free flow is allowed and an angled position of less than 90.degree. to one side of the port whereby maximum charge swirl is obtained in the cylinder.

Abstract: A method is provided for the control of nitrogen oxide and carbon monoxide emissions from a digester gas engine by the injection of air immediately upstream of the intake valve to form a gradient charge in the combustion chamber having an incombustible portion adjacent the piston and a more concentrated combustible portion adjacent the spark plug, and by the calibration of the spark advance curve of the engine.

Abstract: A two-stroke internal combustion engine comprising a cylinder head 14 having combustion chambers 18 with two intake valves 24 and two exhaust valves 26 arranged therein. Two intake manifolds 30 and 32, respectively, have branch pipes connected to each respective intake port 24. An intake control valve 48 l is arranged in one of the manifold 32, which closes at idling and under a low load of the engine. Further, a swirl S is generated about an axis of the combustion chamber 18 by a portion of exhaust gas caused to flow back from the exhaust ports 22 into the combustion chamber 18 after being once exhausted through the exhaust ports when the exhaust valves are opened, resulting in a two layered stratification in the combustion chamber between fresh air and remaining exhaust gas. A supply of fuel causees a further three layered stratification among a fuel mixture, fresh air, and burned gas, by supplying fuel at alternating cycles of the engine when the engine is under a low load.

Abstract: An internal combustion engine is provided with a fuel injection valve in an intake passage communicated with a combustion chamber and a swirl controlling device for controlling a swirling motion to be given to intake air in a circumferential direction of the cylinder forming the combustion chamber. When the engine load is low, the fuel injection valve is controlled to inject fuel by an amount required for one power stroke a predetermined time after the intake valve is opened and during the intake stroke, and the swirl controlling device is controlled to give intake air a swirling motion. A correction device is provided, which, when the engine is cold, controls the fuel injection valve to start fuel injection before the intake valve is opened and also controls the swirl controlling device to suppress production of swirling motion of intake air.

Abstract: An intake system for an engine is disclosed in which an inlet passageway for one cylinder includes a common inlet passageway and first and second branch inlet passages having a branch portion at a downstream side of the common inlet passageway, said first branch inlet passage communicating with a first inlet port and said second branch inlet passage communicating with a second inlet port; said first inlet port having an opening for the cylinder and being designed to allow air to be admitted into the cylinder in a direction in which the air swirls therein, and said second inlet port having an opening therefor and being designed to cause air to be admitted thereinto in a direction it disturbs formation of such swirls; and said inlet passageway being provided at its inner wall portion with a wall member for deflecting air admitted from the common inlet passageway toward the first branch inlet passage.

Abstract: An air inlet nozzle is mounted in a valve pocket above the intake valve of a combustion chamber to allow high speed airflow to mix with fuel in the pocket and enter the combustion chamber to create desired air swirl. Airflow through the nozzle is varied by a computer operated solenoid.

Abstract: An engine intake system including a main intake passage leading through an intake port to a combustion chamber, an auxiliary intake passage branched from the main intake passage and opened to the intake passage, and a control valve provided in the main intake passage and adapted to be opened under a heavy load engine operation and closed under a light load engine operation. A fuel injection valve is provided in the auxiliary intake passage close to the opening of the intake port to the combustion chamber to inject fuel toward the combustion chamber.

Abstract: A combustion chamber is defined by a cylinder having an upper wall surface shaped like a pent-roof and a piston provided on the head portion thereof with a bulged portion conforming to the upper wall surface in shape. A semi-spherical first bowl portion is formed substantially at the center of the bulged portion, and a pair of second bowl portions are formed in the bulged portion to respectively extend on opposite sides of the first bowl portion to the corresponding ends of the bulged portion of the piston along the edge of the bulged portion and to be communicated with the first bowl portion. A swirl generating mechanism is provided to generate a swirl of intake air in the combustion chamber when the engine load is light, and a spark plug is disposed to substantially face the center of the first bowl portion from the upper wall surface.

Abstract: An engine comprising a piston having a cavity formed on the top face thereof. A projection having an impingement face at the top thereof is formed at the center of the cavity. Fuel is injected from a fuel injector toward the impingement face to form a richer air-fuel mixture around the projection. A spark plug or a glow plug is arranged to ignite the richer air-fuel mixture at the end of the compression stroke.

Abstract: An improved induction system for a V type engine that is tuned for substantially all running conditions and which is nevertheless compact in construction. The system includes a pair of plenum chambers each disposed adjacent one of the cylinder heads of the engine. Each cylinder head has at least two intake passages serving the respective cylinder bores and a first conduit extends from the adjacent plenum chamber to one of the intake passages and a second conduit extends from the other of the plenum chambers to the other intake passage. The plenum chambers communicate with each other at their opposite ends to improve air flow and a common inlet opening serves each plenum chamber inlet. A throttle valve arrangement is also incorporated so that good performance is achieved under all running conditions. The throttle valve arrangement includes a throttle valve that controls the flow through the interconnecting passage.

Abstract: Four-stroke combustion engine comprising a cylinder block having a cylinder in which a piston can move, a cylinder head with an intake manifold whose intake opening forms part of the cylinder head, said opening being opened or closed by an intake valve and with a by-pass which is separated from the main inlet channel and has a discharge opening direct into said inlet channel, upstream of the valve, whereby besides the by-pass (2) for air in the main inlet channel (6) also an injector (1) opens into this intake manifold (6) in such a place and such a position that the center line of the fuel jet is directed at the foot of the inlet valve (5).

Abstract: In an internal combustion engine having two intake valves on one side and two exhaust valves on the other side of each cylinder, all four valves are displaced towards the exhaust valve side to provide room for a squish zone on the intake valve side. The squish zone is formed in such a way that the mixture is directed or "squished" in the direction of the spark plug to provide turbulence for improving combustion, especially during partial load operation.

Abstract: At least one inlet channel (4) for each cylinder is developed as a filler channel in which there is a flap valve (13) turning on an axis (12). During full load operation, the flap valve (13) is in a rest position, which does not influence the flow through the inlet channel (4). During partial load operation, however, the flap valve (13) is in a working position, in which it shapes the flow in the inlet channel so unsymmetrically that at the mouth (6) of the inlet channel (4) leading into the cylinder (1) the compressed air flowing out in large quantities has a tendency toward spiral and/or turbulence-reinforcing directions. In this way, fuel preparation is improved during the partial load operation of the motor, leading to combustion with low smoke and noxious substance levels and low consumption.

Abstract: The procedure for the introduction of a layer charge for Otto motors uses a richer mixture in the area of the spark plug and a correspondingly weaker for the remaining areas. The rich mixture is led under pressure through "squish" spaces to the spark plug, in which, in one embodiment, at least one flow vortex accelerated at medium power by the type and shape of the combustion chamber together with the position of the "squish" spaces is created. In this way a very low fuel consumption at minimal carbon monoxide, hydrocarbon and nitrogen content of the exhaust gas is achieved. The motor can be driven at a total mixture composition of Lambda 1.5 or more, in which a readily ignitable mixture of Lambda 0.8 to 1.0 is injected into in the area of the spark plug.

Abstract: A cylinder head for an engine is formed with a first straight intake passage which leads to a first intake port, and with a second helical intake passage which leads to a second intake port and is formed with a helical end vortex portion. A common intake passage leads to the upstream ends of the first and second intake passages. A dividing ridge extends from one side of the inner surface of the cylinder head defining the intake passages towards but not reaching an opposite side of that surface, with a gap being left beween the ridge summit portion and that opposite side. The ridge thus divides the second intake passage into a one side portion remote from the first intake passage and terminating in the helical end vortex portion, and another side portion towards that first intake passage which is a straight bypass passage and is communicated at its downstream end to that helical end vortex portion.

Abstract: An internal combustion engine has a cylinder head and at least two cylinders. Two intake valves are provided for each cylinder. A siamese intake port comprising a common port, a helical port and straight port is formed in the cylinder head. The helical port is communicated with one of the intake valves of one of the cylinders, and the straight port is communicated with one of the intake valves of the other cylinder.

Abstract: In a four-valve engine having a pair of intake ports and a pair of exhaust ports, the hole for inserting the spark plug or the fuel injection nozzle is obliquely formed between the exhaust ports so that one end of the hole opens in the lower surface of the cylinder head at the center of the combustion chamber and the other end of the hole opens between the spring seat portions for the exhaust valve springs and the opening of the exhaust ports in the side face of the cylinder head.

Abstract: A two-cycle internal combustion engine comprises a cylinder head having an intake port and exhaust port opened to a combustion chamber, to which compressed fresh air is introduced via an intake valve. The intake and exhaust valves are operated in response to a crank angle. A pulsation pressure of exhaust gas in the exhaust port is substantially restrained during an idling or light load running condition. The exhaust valve is opened earlier than the intake valve when the speed of the downward movement of the piston is relatively high, such that a part of exhaust gas in the exhaust port flows back to the combustion chamber in that condition. An exhaust gas swirl rotating around a cylinder axis is formed when the exhaust gas flows back and the fresh air is slowly introduced onto the exhaust gas swirl in that condition.

Abstract: Several embodiments of induction systems for internal combustion engines that improve maximum power and also provide good running at low and medium speeds with a good torque curve throughout the engine speed range. Each embodiment includes a pair of intake passages that serve each chamber of the engine through a respective pair of intake valves. The intake passages are each tuned to serve a different running condition of the engine.

Abstract: In order to avoid fuel injection nozzles with a control range extending over the entire load range of the engine, in an internal combustion engine equipped with two intake pipes per cylinder and wherein, furthermore, one intake manifold each supplies intake pipes optimized for low air throughput ranges for high air throughput ranges, there are provided in only one each of the intake pipes fuel injection nozzles each associated individually with one intake pipe, which nozzles are designed for the requirements in a low air throughput range while a fuel injection nozzle common to all cylinders is provided in the intake manifold associated with the other intake pipes.

Abstract: An intake system construction for an internal combustion engine having a generally straight first intake port, a generally helical second intake port, both intake ports opening to one combustion chamber, and a common intake passage for supplying fuel-air mixture to the two intake ports. A control valve is fitted in the first intake port for selectively throttling the first intake port at low load operation of the engine, and a deflection valve is fitted in the commmon intake passage for selectively constricting intake flow through the common intake passage to deflect the flow toward the second intake port and away from the first intake port at low load operation of the engine, so that fuel accumulation on the cotrol valve closed at low load operation of the engine is avoided.

Abstract: An intake system for an internal combustion engine comprises a first valve provided to open and close an intake passage leading to each combustion chamber, a bypass passage for introducing intake air into each combustion chamber bypassing the first valve, and a second valve provided to open and close each of the bypass passages. The first valves are operated to close the respective intake passages in a light load range and to open the same in a heavy load range. The second valve is operated to close the bypass passage in the middle of each intake stroke. The first valves are controlled so that the opening of the intake passages is increased as the engine load increases after exceeding a predetermined value, and the second valve is controlled to delay the time the bypass passage is closed with increase in the engine load so that the time the bypass passage is opened overlaps with the time the intake valve is opened when the engine load reaches the predetermined value.

Abstract: An internal combustion engine in which a minor portion of the air-fuel mixture being flowed to the combustion engine chamber is withdrawn through a fluid withdrawal passage. The fluid withdrawal passage enters the curved outlet section of the intake passage, with its inlet at the convexly curved interior surface of such outlet. The side stream of air-fuel mixture is withdrawn by application of suction to the outer end of such fluid withdrawal passage. Withdrawal of a side stream of air-fuel mixture in this fashion has been found to substantially increase the rate of flow of air-fuel mixture to the combustion chamber during the charging step of engine operation.The fluid withdrawal apparatus and method of the invention are potentially applicable to many other types of fluid flow systems comprising a flow path with a curved portion, downstream of which it is desirable to increase fluid velocity and volumetric flow rate.

Abstract: The invention relates to a cylinder-type head for an internal combustion engine, preferably an Otto-type engine, with four valves per cylinder. The cylinder head accommodates at least one combustion chamber with a pair of inlet ports situated side by side and a pair of exhaust ports, situated opposite the inlet ports. With the object of facilitating gas flowing into the combustion chamber to swirl about the cylinder axis, the invention is essentially distinguished in that the interior surface of the combustion chamber between an inlet port and an exhaust port is implemented with a swirl-generating means. At the intersection between the base plane of the cylinder head, said means form a protrusion projecting radially inwards. The remaining interior surfaces of the combustion chamber lack such protrusion at the intersection with the base plane.

Abstract: The present invention relates to an intake system with double intake ports for internal combustion engine, involving two intake ports for each cylinder chamber of the engine, one of the two intake ports being a pure helical port which introduces suction air with helical flow, but without straightway flow, into the cylinder chamber, and another intake port being partially helical port which introduces suction air with helical flow and straightway flow into the cylinder chamber, the outlets of the two intake ports being preferably located in nearer side of the center of the cylinder chamber, and side by side in a parallel direction with the axis of cam shaft; and preferably the pure helical intake port being suspended in lower speed range by pausing device having pause valve which is preferably consisted of suction valve; and the length of suction passage being preferably varied in accordance with the variation of speed ranges.

Abstract: An intake arrangement for an internal combustion engine provided with a intake construction capable of generating a swirl effective for improving combustibility within a combustion chamber during low load operating conditions of the engine, without substantially altering a two intake port system aiming at a high output of the engine.

Abstract: An engine having a rotary valve arranged in the intake port. The valve shaft of the rotary valve is eccentrically arranged relative to the longitudinal axis of the intake port. A projecting wall projects downward from the upper wall of the intake port and surrounds the valve guide of the intake valve. The projecting wall has an air flow guide portion the thickness and width of which gradually decreases in the direction towards the rotary valve. The upstream end of the air flow guide portion is aligned with the valve plate of the rotary valve when the rotary valve is fully open.

Abstract: A variable swirl siamese type intake port structure for an internal combustion engine cylinder head includes a first generally straight intake passage which leads to a first intake port and a second generally helical intake passage which leads to a second intake port which is formed with a helical end vortex portion. A control valve is fitted in the first generally straight intake passage at an upstream portion thereof so as to control its flow resistance. A bypass passage opens from a point downstream of the control valve in the first generally straight intake passage to the helical end vortex portion of the second intake port. And a downstream portion of the bypass passage is communicated to a downstream portion of the second generally helical intake passage. Thereby the resistance to flow of air-fuel mixture of the generally helical intake passage is diminished, and the engine volumetric efficiency and the maximum attainable engine output power are increased.

Abstract: An inlet port for an internal combustion engine having an inlet hole opened on an end face of a cylinder chamber at an off-center position, the inlet hole being provided with an inlet valve and connected to an inlet passage.

Abstract: An intake system for a direct fuel injection diesel engine is disclosed which has a cylinder block with a cylinder slidingly receiving a piston. A cylinder head is mounted on the cylinder block, and a fuel injector is adapted to directly inject fuel into a combustion chamber formed between the lower side of the cylinder head and the upper side of the piston, wherein the cylinder head has first and second intake passages which are independent of each other and which are adapted to introduce air into the combustion chamber. The first intake passage is oriented substantially tangentially to the combustion chamber and substantially orthogonally to the axis of the cylinder, and has a helical end portion opening into the combustion chamber to form a swirl of air flowing therethrough. The second intake passage is oriented such that the end portion thereof, adjacent the combustion chamber, is closer to the central axis of the cylinder than the end portion of the first intake passage adjacent the combustion chamber.

Abstract: A diesel engine intake system including a timing valve which is positioned in the intake system in engine starting and warming-up period under a cold engine condition. The timing valve is opened in the final period of the intake stroke so that a strong suction pressure is produced in the combustion chamber before the timing valve is opened. When the timing valve is opened, the intake air is rushed into the combustion chamber at a high speed whereby the intake air is compressed under the inertia of the high speed flow to thereby increase the temperature of the intake air. The timing valve is responsive to the suction pressure in the combustion chamber and opened when the suction pressure becomes stronger than a predetermined level.

Abstract: A valve placement arrangement for an internal combustion engine including at least three intake valves and two exhaust valves and wherein no two of the exhaust valves are adjacent to each other and they are separated by intake valves so as to insure against undue heating and minimize thermo-loading.

Abstract: A variable swirl siamese type intake port structure for an internal combustion engine cylinder head includes a first generally straight intake passage which leads to a first intake port and a second generally helical intake passage which leads to a second intake port which is formed with a helical end vortex portion. A control valve is fitted in the first generally straight intake passage at an upstream portion thereof so as to control its flow resistance. A means is provided to the generally straight intake passage on the side thereof towards the generally helical intake passage, for, when the control valve is in its position to maximize the flow resistance of the generally straight intake passage, diverting a relatively minor proportion of air-fuel mixture sucked into the intake port structure from a point upstream of the control valve to a point near the downstream end of the first generally straight intake passage, thus bypassing the control valve.

Abstract: An injection system for an internal-combustion engine has a plurality of separate inlet ports provided for each cylinder of the engine, and an intake pipe encompassing the inlet ports for each cylinder. The intake pipe has a subdividing web wall in the region of the cylinder head having a mixing chamber into which fuel is injected by an injection nozzle. The subdividing web wall subdivides the intake pipe into separate intake pipe sections and includes shot channels for communicating fuel from the mixing chamber to each of the separate intake pipe sections. By this arrangement, a constant, thorough mixing of the fuel/air mixture is achieved even at lower load and upper speed ranges of the engine.

Abstract: A variable swirl siamese type intake port structure for an internal combustion engine cylinder head includes a first generally straight intake passage which leads to a first intake port and a second generally helical intake passage which leads to a second intake port which is formed with a helical end vortex portion. A control valve is fitted in the first generally straight intake passage at an upstream portion thereof so as to control its flow resistance. A substantially straight auxiliary passage, opening from a point upstream of the control valve to a point near the downstream end of the first intake port and bypassing the control valve, points through the first intake port, when open, generally at the ignition point of the engine spark plug. Thereby, when the control valve is closed, even then an air-fuel mixture stream is directed straight at the spark plug, and this prevents local weakening of mixture due to centrifugal effects.

Abstract: An internal combustion engine comprising three intake valves. The first intake valve and the second intake valve open at a crank angle near to the top dead center of the intake stroke. The third intake valve opens approximately at the center of the intake stroke. An air control valve is arranged in the second intake passage connected to the combustion chamber via the second intake valve. The air control valve is closed when the engine is operating under a partial load. A fuel injector is arranged in the third intake passage connected to the combustion chamber via the third intake valve. The injecting operation of the fuel injector is stopped during the intake stroke.

Abstract: Adiabatic positive displacement gas cycle machinery is designed with explicit control of the heat flow between the gas and the walls. The control is achieved by maintaining near-laminar flow and a small wall area to volume ratio. The most stable near-laminar flow in a cylinder is an axial vortex because of symmetry, and hence the induction port design should establish an axial vortex and a low velocity. Induction and exhaust port designs to achieve this flow are applied to a vane pump, an adiabatic air compressor, a diesel engine, and two and four stroke Otto cycle engines. The gain in thermal efficiency for these designs can be significant, up to a factor of 2, since the largest inefficiency in nearly all positive displacement machinery is imperfect control of heat flow.

Abstract: An induction system for an internal combustion engine that improves mid range torque without sacrificing low speed running or high speed performance. Each cylinder of the engine is served by two intake ports that are, in turn, served by respective intake passages that have a common portion. A first throttle valve is positioned in the common portion for precluding the back flow of exhaust gases and for controlling the flow to the chamber. In addition, first and second inlet passages discharge into the common intake passage and a throttle valve is positioned in one of those inlet passages.

Abstract: The combustion chamber for an internal combustion engine is formed by a main combustion chamber defined by a recess formed in a part of the lower face of a cylinder head and a squish zone which is a narrow space formed between the top surface of the piston in the top dead center and the substantially flat portion of the lower surface of the cylinder head around the recess. A spark plug is disposed in a position near the squish zone. A fuel injection valve is provided to inject fuel into an intake passage communicated with the combustion chamber by way of an intake valve. The fuel injection valve is controlled, at least when the engine load is low, to inject fuel by an amount required for one power stroke and to terminate fuel injection before the middle of the intake valve opening time at latest so that stratification of air and fuel can be obtained in which rich mixture is accumulated in the lower portion of the combustion chamber and lean mixture in the upper portion of the same.

Abstract: A combustion chamber configuration for an engine having three intake valves and two exhaust valves per cylinder. The combustion chamber configuration permits the use of stroke-to-bore ratios of 0.8 to 1 or less and compression ratios of 9 to 1 or greater while affording good flame travel in the combustion chamber. The piston is formed with a generally flat head that has semi-circular recesses for valve clearance.

Abstract: A method of operating an internal combustion engine with alternative preheated fuels, or mixtures thereof, at the same compression ratio and supplied with an additional medium for the operation comprisesdetecting the flow of air drawn into the engine through the air intake,proportioning and distributing the fuel to each cylinder in response to at least detected flow,heating the fuel fed to each cylinder to a temperature between its flame temperature and above its evaporation temperature, but below its auto ignition temperature, andinjecting the heated fuel and the additional medium in a controlled amount into each cylinder through separate feed means at different angles with respect to the wall of the respective cylinder.