Abstract: A combination carburetor backing plate and crankcase breather for a motorcycle engine having at least a pair of cylinders, a cylinder head mounted on each cylinder, and a valve for connecting each cylinder head to the crankcase for venting the same through an exit port in the cylinder head. The combination includes a plate having a first side adapted for mounting to a carburetor and to the cylinder heads, and an opposite, second side adapted for mounting an air cleaner. The plate has a centrally disposed first aperture that coaxially aligns with the carburetor throat, and second and third apertures that align with the exit ports on the cylinder heads. Hollow bolts are provided for insertion through the second and third apertures for threaded attachment to the exit ports, whereby the second and third apertures communicate with the exit ports.

Abstract: A method wherein a number of cylinders (2, 3; 1, 4) are grouped on a same exhaust gas manifold (8, 10) such that the pressure in the exhaust pipe (1e . . . 4e) undergoes time-dependent fluctuations of substantial amplitudes, and the exhaust valve (6) of a cylinder (1) is opened during induction or filling thereof (i.e. adjacent to the bottom dead center) so that, in a given engine speed range, a phase (28) of low instantaneous exhaust pressure prevailing in the exhaust pipe enables the inlet pipe (1a)/cylinder (1)/exhaust pipe (1e) to be scavenged while the inlet valve (5) and the exhaust valve (6) are simultaneously open. The phase (29) of high instantaneous exhaust pressure, caused by another cylinder, after the inlet valve (5) has closed and while the exhaust valve (6) is still open, is used for post-charging the cylinder (1) with air (A) previously stored in the exhaust pipe (1e).

Abstract: A four-cycle internal combustion engine wherein the piston connecting rod crankshaft and crankcase chamber are formed so that the crankcase chamber acts as compressor. An induction system supplies atmospheric air to the crankcase chamber and a pressure conduit supplies air from the crankcase chamber to the engine intake valve. A plenum chamber is disposed within this pressure conduit and pressure control is possible by bypassing air form the plenum chamber to the atmospheric air inlet. A throttle valve is positioned downstream of the plenum chamber so as to improve engine braking and charge forming systems are disclosed that permit a compact assembly and good response under all engine running conditions.

Abstract: The invention concerns a two-stroke internal combustion engine and a method of operating a two-stroke internal combustion engine which includes at least one cylinder (10) with a piston (20) reciprocating therein and with at least one inlet (40) and exhaust duct (70), wherein the inlet duct (40) is arranged in relation to the exhaust duct (70) in accordance with the uniflow scavenging process in such a way that the inlet duct (40) opens into the cylinder in the region of the combustion chamber (30) and wherein a regulating element (50) is provided in the mouth opening region of the inlet duct (40). In that arrangement the regulating element (50) of the inlet duct (40) can be adapted to be controllable and a controllable regulating element (80) can also be arranged in particular in the mouth opening region of the exhaust duct (70).

Abstract: Disclosed is a device for controlling the flow of intake and exhaust gases in an internal combustion engine, which comprises a cylinder head with a plurality of cylinders each forming combustion chamber for burning air/fuel mixture to produce a mechanical energy, the combustion chamber having an intake valve for receiving an air/fuel mixture and an exhaust valve for exhausting burnt gases, a blocking means for isolating the side of the intake valve from the side of the exhaust valve so as to prevent a fresh air/fuel mixture and the burnt gases from interfering with each other in the overlap interval between the final stage of the exhaust stroke and the beginning stage of the intake stroke during which the intake and exhaust valves simultaneously maintain the opening state, and a cam shaft for driving the intake and exhaust valves and the blocking means.

Abstract: A two-stroke engine comprising two exhaust valves and two intake valves. These exhaust valves and these intake valves are arranged on the peripheral portion of the inner wall of the cylinder head, and one additional exhaust valve is arranged on the central portion of the inner wall of the cylinder head. The valve openings of the two intake valves, which are located on the exhaust valves side, are masked by the masking walls.

Abstract: A two-stroke engine comprising a spark plug arranged at the center of the inner wall of the cylinder head, and a fuel injector arranged on the periphery of the inner wall of the cylinder head. A depression extending from the point beneath the spark plug to the point beneath the tip portion of the fuel injector is formed on the top face of the piston. When the engine is operating under a light load, fuel is injected by the fuel injector only once toward the depression, and conversely, when the engine is operating under an intermediate load, fuel is injected twice. Namely, a first injection is carried out when the piston is at a lower position, and a second injection is carried out when the piston is at a higher position, to thus direct fuel toward the depression.

Abstract: A two-stroke engine comprising three exhaust valves and two intake valves. These exhaust valves and these intake valves are arranged on the peripheral portion of the inner wall of the cylinder head, and one additional intake valve is arranged on the central portion of the inner wall of the cylinder head. The valve openings of the three intake valves, which are located on the exhaust valves side, are masked by the masking walls. The central portion of the combustion chamber is scavenged by the fresh air fed from the additional intake valve, and the peripheral portion of the combustion chamber is scavenged by the fresh air fed from the remaining two intake valves.

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 two stroke diesel engine having a cavity in the cylinder head facing the combustion chamber, an intake valve and exhaust valve, a fuel injector, and a projection formed on the piston head. The intake valves and fuel injector are pointing toward the cavity while the exhaust valve is pointing toward the combustion chamber. The projection enters the cavity in the vicinity of the top dead center of the piston movement and separates it from the combustion chamber. Due to the loop effect of fresh gas flowing from the intake valve into the combustion chamber via the cavity, burnt gas is swept out of the chamber effectively, and due to the energy of combustion of fuel and air which ignited in the closed cavity, combustion rapidly spreads throughout the combustion chamber as the piston descends so that air is utilized efficiently.

Abstract: In a two stroke diesel engine which comprises a combustion chamber formed by a cylinder, piston head and base of the cylinder head, a cavity formed on the base of the cylinder head facing the combustion chamber, intake valves fitted to the cylinder head facing the cavity, a fuel injection valve fitted to the cylinder head facing the cavity, and exhaust valves fitted to the base of the cylinder head, fresh gas entering from the intake valves flows into the combustion chamber via the cavity in a scavenging step, and effectively sweeps out burnt gas. Further, as fuel and air are mixed in the cavity near the top dead center of the piston stroke, and this gas mixture is ejected together with the flame that ignited in the cavity into the combustion chamber as the piston descends, combustion in the chamber takes place efficiently.

Abstract: A two-stroke engine including a pair of intake valves. A masking wall is provided for each intake valve to mask the valve opening between the valve seat and the peripheral portion of the intake valve, which is located on the exhaust valve side, for the entire time for which the intake valve is open. The exhaust valves open earlier than the intake valves, and the exhaust valves and the intake valves are closed at substantially the same time.

Abstract: The two-stroke cycle engine employing intake and exhaust valves comprises a combustion and scavenging prechamber having substantially a shape of revolution about an axis and provided with an intake valve seat. Deflecting means or vanes are disposed inside the intake pipe as directly as possible on the upstream side of the seat so as to urge the mass of air into the combustion chamber in the manner of a whirl.

Abstract: A two-stroke engine having an intake valve and an exhaust valve arranged on an inner wall of the cylinder head, an intake passage connected to the cylinder via the intake valve, a fuel injection device arranged in the cylinder, for injecting fuel into the cylinder, a pressure regulator for regulating a fuel pressure supplied to the fuel injection device on the basis of a scavenging pressure in the intake passage, to thereby increase the fuel pressure in accordance with an increase of the scavenging pressure, and a control device for controlling the injection of fuel by the fuel injection device for a time ranging from a time at which the intake valve is opened to a time at which the scavenging pressure becomes equal to a pressure in the cylinder after the intake valve is closed.

Abstract: A two-stroke internal combustion engine provided with a masking wall (8a, 40b) which is disposed between an intake valve (6) and exhaust valve (7) disposed on a cylinder head inner wall surface (3a) and which closes the opening between the peripheral edge of the intake valve (6) and valve seat (9) positioned at the exhaust valve (7) side, over the period of full opening of the intake valve (6), and a fuel injection valve (14, 42) which is disposed at the peripheral side portion of the cylinder head inner wall surface (3a) at the intake valve (6) side, wherein the fuel injection from the fuel injection valve (14, 42) to the cylinder (1) is started when the intake valve (6) opens. By this, it is possible to easily ignite the fuel and to stabilize the combustion after ignition.

Abstract: A two-stroke internal combustion engine, in particular of the diesel type, which comprises at least one intake valve (10) having its seat disposed in the wall of a combustion and scavenging prechamber (13) and at least one exhaust valve (7), is characterized in that the prechamber (13) communicates with the cylinder (1) through a transfer passageway (14) whose walls are at least partially substantially parallel to the axis (2) of the cylinder and whose cross-section perpendicular to this axis opens out in accordance with a substantially oblong shape tangent to the cylinder (1). An improved effectiveness of the engine is obtained.

Abstract: A rotary lawn mower having an air-cooled single cylinder four-cycle internal combustion engine for powering its cutting blade. The engine is air cooled and is disposed so that its exhaust port lies above the intake port and the carburetor is positioned above a raised portion of the scroll part of the lawn mower housing for good cooling of the exhaust port without heating of the carburetor. A valve operating mechanism is disclosed including a pair of push rods that are supported on the exhaust port side of the engine and which are surrounded by a mass of cylinder head and cylinder for assisting in heat dissipation.

Abstract: An engine, operating in accordance with the two-stroke cycle, is characterized in that the intake and exhaust timing elements are valves (7, 9). The control device for the valves is responsive to a parameter such as the speed of rotation of the engine, the comsumption of fuel, the value of a super-charging pressure, or the difference between the intake and the exhaust pressure. The control device is used for varying the angular position in the cycle of operation of the opening and the closure of the valves (7, 9) to obtain the introduction of a sufficient quantity of fresh air in the work chamber in the least favorable condition of operation, in particular by opening the intake during a period of increase in volume of the chamber.

Abstract: An air-cooled internal combustion engine, a crankshaft and a camshaft rotatably journalled in the crankcase parallel to one another, and a cast intake valve chamber and cast exhaust valve chamber each cast integrally with the cylinder and communicating with the combustion chamber via a respective intake valve port and exhaust valve port. Intake and exhaust valves are disposed for reciprocation in a direction lying perpendicular to the camshaft and simultaneously in a direction lying at an acute angle to a plane passing through the longitudinal axis of the cylinder and parallel to the axis of the camshaft. An intake cross-over manifold is cast integrally with the cylinder and is delimited by interior walls which are substantially straight in longitudinal direction from a fuel/air intake port to a point of intersection with the intake valve chamber.

Abstract: A two-stroke engine including a pair of intake valves which are symmetrically arranged with respect to a symmetrical plane including the axis of the cylinder. A masking wall is provided for each intake valve to mask the valve opening between the valve seat and the peripheral portion of the intake valve, which is located on the exhaust valve side, for the entire time for which the intake valve is open. These masking walls are also symmetrically arranged with respect to the symmetrical plane.

Abstract: The cylinder head (401) of a turbocompounded 2-stroke piston engine incorporates, for each cylinder (400), an indirect combustion chamber (402) which is connected to the cylinder clearance volume (413) by a passage (412). The indirect combustion chamber (402) incorporates the inlet valve (408) so that when the valve opens, turbocharging air flows into the cylinder through the chamber (402) and the passage (412). This allows a large proportion of the cylinder head area to be devoted to the exhaust valves (410), with advantages in good scavenging and maximising mass flow rates through the cylinder.

Abstract: A two-stroke cycle internal combustion engine without crankcase scavenging is disclosed which is able to operate in a four-stroke mode at cranking and idle speeds. The engine utilizes a turbocharger driven by exhaust gases to recharge the cylinder with fresh air or an air/fuel mixture. An auxiliary inlet valve responsive to pressure within the cylinder enables the engine to operate in a four-stroke mode, thus eliminating the need for an externally driven air pump when the engine is either idling, being started, or under light loads where turbocharger boost is too low to supply sufficient flow of air or an air/fuel mixture.

Abstract: A high power, fuel efficient, low-emission, four-stroke, 6 cycle method of operation. A primary intake conduit carries air or a lean mixture from the compression chamber (crankcase) to the combustion chamber. Fuel is added to the air or lean mixture as it passes through the intake conduit. A secondary intake conduit runs from the compression chamber to ports in the cylinder located slightly above the bottom dead center position of the piston. Supplemental air or lean mixture from the compression chamber is fed to the combustion chamber through the secondary conduit when the piston is near its bottom dead center position. While the piston is in its bottom dead center position between its intake and compression strokes, the air or lean mixture from compression chamber provides a stratified charge in the combustion chamber, which is far more efficient than a homogeneous mixture, and has the further benefit of filling the cylinder from the bottom as well as from the top.

Abstract: A two-stroke internal combustion engine, in particular of the diesel type, which comprises at least one intake valve (10) having its seat disposed in the wall of a combustion and scavenging prechamber (13) and at least one exhaust valve (7), is characterized in that the prechamber (13) communicates with the cylinder (1) through a transfer passageway (14) whose walls are at least partially substantially parallel to the axis (2) of the cylinder and whose cross-section perpendicular to this axis opens out in accordance with a substantially oblong shape tangent to the cylinder (1). An improved effectiveness of the engine is obtained.

Abstract: A two-stroke engine having an intake valve and an exhaust valve which are arranged on the cylinder head. A masking wall is formed on the inner wall of the cylinder head to mask the valve opening between the valve seat and the peripheral portion of the intake valve, which is located on the exhaust valve side, for the entire time for which the intake valve is open.

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: The cylinder head (401) of a turbocompounded 2-stroke piston engine incorporates, for each cylinder (400), an indirect combustion chamber (402) which is connected to the cylinder clearance volume (413) by a passage (412). The indirect combustion chamber (402) incorporates the inlet valve (408) so that when the valve opens, turbocharging air flows into the cylinder through the chamber (402) and the passage (412). This allows a large proportion of the cylinder head area to be devoted to the exhaust valves (410), with advantages in good scavenging and maximizing mass flow rates through the cylinder.

Abstract: A two-cycle internal combustion engine having three, or a multiple of three, cylinders comprises a cylinder head having an intake port and exhaust port opened to a combustion chamber, to which fresh air compressed by a supercharger is introduced via an intake valve. The intake and exhaust valves are operated in response to a crank angle. A one-way valve is provided in the intake port so as to prevent air or gas from flowing back toward the supercharger. The exhaust valve is opened earlier than the intake valve when the speed of the downward movement of the piston is relatively high, so that a part of exhaust gas in the exhaust port flows back to the combustion chamber in the condition. In a heavy load condtion, cross scavenging and air charging effects due to exhaust pulsation can be achieved.

Abstract: A two-cycle internal combustion engine comprises a cylinder head having an intake port and two exhaust ports opened to a combustion chamber, to which compressed fresh air is introduced via an intake valve. The intake valve and two exhaust valves are operated in response to a crank angle. One of the exhaust valves is opened earlier than the other exhaust valve and 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 one 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: 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. An inclined concavity is formed on a top face of a piston. An exhaust valve is opened earlier than the intake valve when the speed of the downward movement of the piston is relatively high, so 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. The inclined concavity serves to smoothly guide the exhaust swirl.

Abstract: A two cycle internal combustion piston engine is provided with cam controlled inlet valves, as well as exhaust valves, disposed in the head of the engine cylinder. The two cycle engine can perform with an expansion ratio greater than the compression ratio. A standard two cycle internal combustion piston engine can be converted to the inventive two cycle engine construction by replacing the conventional engine cylinder head, replacing the conventional engine valve cam shaft, and directing air flow in the intake manifold to one side of the replacement cylinder head.

Abstract: A two-cycle internal combustion engine having an "open" combustion chamber/poppet valve arrangement that produces improved scavenging. The combustion chamber has a generally oblate configuration and is slanted with respect to the cylinder axis in such a manner that the air flowing therein converges and is directed downward in a collimated column into the cylinder. The placement of overhead cam operated poppet valves in combination with the combustion chamber produces a scavenging method of the reverse return-flow type. A displacer piston having a displacer with a peripheral wall corresponding in configuration to that of the combustion chamber and defining a recess of predetermined volume that forms the floor of the combustion chamber when the piston is located in its upper most position may be advantageously employed.

Abstract: A suction air passage of the side-valve type of internal combustion engines is composed of a pipe-shaped portion which is integrated into the cylinder, for example by means of metal mold, and is opened at its outside, and a cover which is fixed to the pipe-shaped portion to close the opening thereof.

Abstract: An internal combustion heat engine and cycle therefor comprising a two stroke cylinder and piston unit having a combustion chamber at the top of the cylinder, having a compression chamber at the bottom of the cylinder, and having a transfer chamber charged with compressed combustion support air transferred into the combustion chamber during initial movement of the piston in a first power stroke, followed by spark ignition and combustion to effect said power stroke with simultaneous compression in said compression chamber and with admission of compressed combustion support air into said transfer chamber during terminal movement of said power stroke, the compressed combustion support air being stored in the transfer chamber during a second exhaust stroke with simultaneous induction of air into the compression chamber.

Abstract: A two cycle, spark ignition, internal combustion engine of the class having a combustion chamber divided into a relatively small ignition region and a larger combustion engine in which the piston reciprocates. Substantially the same stoichiometric fuel-air mixtures are independently supplied to the ignition region in substantially fixed quantities and to the combustion region in variable quantities. These mixtures are compressed simultaneously so that they remain completely separated prior to ignition. The mixtures are stratified with respect to excess air supplied to both regions and to exhaust gases in the engine cylinder, and combustion initiated in the ignition region ignites the variable-sized mixture in the larger region. Burning proceeds from stoichiometric mixtures to lean mixtures as the stratified excess air is mixed into the burning gases. When no fuel is supplied to the combustion region, the ignition region functions independently and burns its fuel efficiently.

Abstract: An internal combustion heat engine and cycle therefor comprising a two stroke cylinder and piston unit having a combustion chamber at the top of the cylinder, having a compression chamber at the bottom of the cylinder, and having a transfer chamber charged with compressed combustion support air transferred into the combustion chamber during initial movement of the piston in a first power stroke, followed by spark ignition and combustion to effect said power stroke with simultaneous compression in said compression chamber and with admission of compressed combustion support air into said transfer chamber during terminal movement of said power stroke, the compressed combustion support air being stored in the transfer chamber during a second exhaust stroke with simultaneous induction of air into the compression chamber.

Abstract: A method and apparatus is disclosed for decreasing fuel consumption in a variably loaded, two cycle internal combustion engine. Fluid communication is provided between the working cylinder and air chamber during the upward stroke of the engine up to about 85.degree.-105.degree. BTDC, during which time the cylinder gases can flow back into the air chamber reducing engine friction as a result of a delay in the rise of the cylinder gas pressure during compression and a reduction in the peak compression pressure.

Abstract: The cylinders of a supercharged two-stroke internal combustion engine have valves, intake and exhaust pipes and a cylinder head constructed for air to be directed from the intake pipe toward the piston along the wall of the cylinders upon opening of the valves and to scavenge the combustion chamber without substantial direct flow of air from the intake pipe to the exhaust pipe along the cylinder head.

Abstract: A two-cycle internal combustion engine having an "open" combustion chamber/poppet valve arrangement that produces improved scavenging. The combustion chamber has a generally oblate configuration and is slanted with respect to the cylinder axis in such a manner that the air flowing therein converges and is directed downward in a collimated column into the cylinder. The placement of overhead cam operated poppet valves in combination with the combustion chamber produces a scavenging method of the reverse return-flow type. A displacer piston having a displacer with a peripheral wall corresponding in configuration to that of the combustion chamber and defining a recess of predetermined volume that forms the floor of the combustion chamber when the piston is located in its upper most position may be advantageously employed.