Abstract: A 2-stroke engine having a combustion chamber and a scavenge port which is open to the combustion chamber. When the engine is operating under a light load in which a large amount of unburned components, incompletely burned components and oxygen remains in the combustion chamber, fresh air is fed into the combustion chamber from the scavenge port at a low speed so that the fresh air does not disturb the residual gas in the combustion chamber. As a result of this, oxidation of the unburned components and the incompletely burned components continues without interruption during the expansion stroke and the compression stroke and causes self-ignition of the residual gas at the end of the compression stroke. The self-ignited residual gas causes ignition of the fuel injected into the combustion chamber from a fuel injector.

Abstract: Two embodiments of lubricating systems for two-cycle internal combustion engines wherein a fuel/lubricant mixture is provided from a carburetor directly to certain components of the engine to be lubricated such as the rod bearings. This separate lubricant passage receives a fuel/lubricant/air mixture and is independent of the main intake passage of the engine. In one embodiment, a separate fuel/lubricant inlet extends into the carburetor downstream of the main induction nozzle. In the other embodiment, this separate lubricant passage has its own induction passage and own fuel/lubricant discharge nozzle.

Abstract: A porting and scavenging system for a two-cycle internal combustion engine that permits a more compact arrangement. The engine employs scavenging passages that lie on opposite sides of a plane passing through the cylinder axis and the center of the exhaust ports. These scavenging passages are arcuate in cross-sections perpendicular to the cylinder axis and their centers lie on the plane but are offset from the cylinder axis to the side opposite the exhaust ports. In addition, the scavenge passages extend at an angle to the cylinder axis so that their outlets into the cylinders disposed further from the exhaust ports than their inlets from the crankcase. This arrangement not only improves compactness but significantly improves scavenging.

Abstract: Two-cycle internal combustion engines are disclosed incorporating intake and transfer ports and passages, and including intake porting at the sides of the cylinder in the regions of an axial plane through the cylinder containing the axis of the wrist pin interconnecting the piston with the crank.

Abstract: A fuel supply system for an internal combustion engine having inlet porting and a fuel supply passage with valve means therein, the cross-sectional area lying within the outside passage walls being greater in the region of the valve means than in a region upstream of the valve means. An element is disposed in the passage tending to equalize the velocity of the fuel flow through the supply passage in different regions thereof, and means are also provided in connection of a fuel reservoir or vessel to the fuel supply passage or channel in the region of and through said element.

Abstract: The invention provides an internal combustion engine comprising a cylinder block having therein a bore and first, second and third openings each communicating with the bore. A cover member having therein first and second cavities is removably attachable on the cylinder block with the first cavity communicating with the first bore opening and the second cavity communicating with each of the second and third bore openings. The cover member cavities and the associated bore openings together form passages communicating with the bore.

Abstract: The two stroke engine includes a V engine block having first and second cylinder banks each with first, second, and third cylinders, which banks are located at a bank angle within the range of from about 60.degree. to about 90.degree., a cylinder firing order wherein corresponding cylinders from alternate banks are successively fired, a cylinder firing interval constituted by a repetitious cycle of crankshaft angles between firings including a first firing interval angle followed by a second firing interval angle, wherein the sum of the first and second firing interval angles equals about 120.degree., and a crankshaft having first, second, and third crankpins respectively associated with the first, second and third cylinders of both of the banks, each of the crankpins being spaced from each other at an angle of about 120.degree.

Abstract: A two-cycle engine is disclosed which conventionally includes a piston that reciprocates between a closed combustion chamber and crankcase. The piston reciprocates through a connecting rod that is eccentrically connected to the crank discs of a crankshaft. The crankcase is partially circular in configuration, and the crankdiscs conform in shape to the crankcase. Each crank disc has an annular recess or pocket extending around its periphery for approximately 180.degree. and in opposition to the eccentric point of connection of the connecting rod. The pockets cyclically communicate with a fuel inlet port and carburetor, both of which are positioned below the crankshaft rotational axis on the downstroke side of the crankcase. Fuel transfer passages between the crankcase and combustion chamber are positioned to receive the fuel charge from each recess as it is thrown tangentially upward with rotation of the crank discs.

Abstract: A two stroke cycle internal combustion engine having a closed crankcase adapted to receive a air-fuel mixture and a cylinder extending from said crankcase,a piston reciprocally movable in said cylinder which alternately produces a low pressure condition in said crankcase as it approaches top dead center and a high pressure condition in said cylinder as it approaches bottom dead center,a fuel reservoir for supplying liquid fuel to the air fuel mixture in said crankcase, a bypass passage connecting said crankcase to said cylinder,and a conduit connecting said crankcase to the fuel reservoir for pumping fuel accumulated in said crankcase during starting into said reservoir, and a unidirectional flow control device in said conduit for preventing return flow from said reservoir to said crankcase.

Abstract: An internal combustion engine operating on a two-stroke cycle and including a piston 1 reciprocable in a cylinder 2 to drive a crank shaft and also to inhale and compress a volume of air is characterized by a second piston 15 working in a separate cylinder 13 co-axial with and opposed to the first cylinder 2, the piston 15 being synchronized with the first piston 1. The second piston 15 acts to introduce a compressed charge of mixture of air and fuel through a non-return valve 30 into a relatively small ignition chamber 34 including a sparking plug 35 and communicating with a combustion chamber 11 in the head of the cylinder 1. The piston 15 draws air/fuel mixture along an inlet passage 20, past a non-return reed valve 21 and into a crank case 22. On the return stroke of the piston 15 the mixture passes through passages 23 in the piston controlled by a non-return valve 24 and also along passages 14 and around the piston.

Abstract: A two cycle engine has a cylinder, a piston axially slidably mounted in said cylinder, and through the wall of the cylinder an intake port, exhaust port, and scavenging port. These ports are respectively connected to intake, exhaust, and scavenging passages. An auxiliary intake passage opens through the cylinder wall, circumferentially spaced from the other intake passage so as to leave an axially-extending side-support surface to permit of an enlarged total intake port area without permitting the piston to tilt or otherwise wander from its true path, thereby to reduce piston clatter and wear, and to improve engine performance.

Abstract: The two-cycle internal combustion engine includes an engine block having a cylindrical wall defining a cylinder having a head end, a piston mounted for reciprocative movement in the cylinder, and a passage in the engine block, such as an exhaust passage, a transfer passage, or a crankcase fuel intake passage, terminating at the cylinder wall in a port, such as an exhaust port, a transfer port or a piston-controlled, crankcase fuel intake port, having upper and lower edges. A valve mounted in the passage for movement relative to the port is operable to selectively vary the effective distance of one of the port edges from the cylinder head end and thereby provide the capability of varying the timing of the port opening and/or closing as required to obtain optimum engine performance at different operating conditions.

Abstract: A front transfer port system to help ensure a regular cooling of the piston and cylinder temperature at the points where the heat conditions are more severe, and to improve the transfer process of the mixture that transfers from the crankcase to the cylinder with more scavenging efficiency to displace spent products to the atmosphere through the exhaust ports in an internal combustion two-stroke cycle engine. The front transfer port system is situated in the cylinder wall at the front and between the exhaust ports.

Abstract: An internal combustion engine comprises a combustion chamber and a piston movable relative to the combustion chamber between top dead center and bottom dead center positions. A fuel transfer passage introduces fuel-air mixture into the combustion chamber in response to piston movement. An auxiliary chamber is also provided which is communicable with the combustion chamber in response to piston movement shortly after the ignition of a fuel-air mixture, such that high pressure ignition gases enter the auxiliary chamber. The high pressure ignition gases thereafter flow back into the combustion chamber in response to piston movement before communication is established between the combustion chamber and the fuel transfer passage. The incoming flow of high pressure ignition gases serves to influence the normal scavenging streams.

Abstract: A two-cycle engine (10) has an idle fuel system which admits fuel-air mixture into the transfer passages (22). Heated air is supplied to the idle mixing passage (42) by a serpentine air passage (45), while fuel from the carburetor float bowl (33) is supplied through a needle valve (50). A reed valve (43) admits the idle mixture to the transfer passage (22).

Abstract: An in-line, multi-cylinder, two-cycle loop charged engine 10 has transfer passages 21, 22, and 23 partially formed by cavities die-cast in the cylinder block 14. The transfer passages are completed by covers, 24 and 25 bolted to the block 14. An efficient loop charging system is thus provided in a completely die-cast cylinder block.

Abstract: A two stroke engine having an exhaust port formed in the cylinder wall. At the upper portion of the exhaust port, there is provided a rotary type exhaust timing control valve which is adapted to be actuated by a centrifugal governor device to control the exhaust timing in accordance with the engine speed. The centrifugal governor device has a governor shaft which extends coaxially with the engine crankshaft and directly connected at one end with the adjacent end of the crankshaft.

Abstract: Two stroke engine having variable exhaust timing, which includes an exhaust timing control member disposed in the exhaust passage in the vicinity of the exhaust port. The control member is of an arcuately curved contour having diameter gradually decreasing from one end toward the other end so that it can readily be assembled in the cylinder simply by inserting from one side of the cylinder. The control member has a longitudinal axis which is inclined with respect to a line perpendicular to a line passing through the center axis of the cylinder and the center of the exhaust port so that the smaller diameter end is closer to the center axis of the cylinder than the large diameter end for making it possible to locate the arcuately curved contour of the control member substantially along the cylinder wall.

Abstract: Improvements in the operation cycle of a two-stroke engine. At least the scavenging residue which is in the exhaust manifold are sucked back into the crankcase of the engine, at the vicinity of the exhaust port of the cylinder independently of the feed system of the carburetor. The invention applies in particular to small engines allowing a reduction in pollution and improvement in efficiency.

Abstract: A transfer duct construction for a two-stroke engine cylinder in which a transfer port in the cylinder wall has a side wall that is perpendicular to the parting line along which the cylinder is cast; a transfer port cover extends over the transfer port and includes an inner end wall having an inclined surface positioned adjacent the perpendicular side wall of the port to direct a fresh fuel-air charge away from an exhaust port.

Abstract: The invention contemplates electronically controlled fuel-injection for a multiple-cylinder two-cycle internal-combustion engine wherein each cylinder has its own independent crankcase region in which to receive and compress inlet air and fuel, prior to delivery of combustible mixture to the head or combustion end of the cylinder. Fuel is injected into each crankcase region during only a portion of the stroke involving induced intake of air therein, i.e., during only a portion of the rise of each piston in its approach to top-center position, and while pressure within the crankcase region is relatively uniform. The time-duration of actual injection is relatively short, thus enabling a plurality of different cylinder injections to be made concurrently, resulting in simplification of fuel-injection control circuitry.

Abstract: A two-stoke cycle combustion-engine with crank-chamber compression is described, free of charging transfer passages external to the cylinder, with pumping-displacement exceeding working-displacement for responsive intake and thorough scavenging of spent-gas residue, and featuring an annular water-cooled cell, suspended from the cylinder-head by several water-conduits, and cooperating with an annular recess in the piston-head so as to form, and transversely separate, a plain working-chamber and an annular working-chamber, longitudinally scavengeable in series, bottom-to-top and top-to-bottom, respectively, with minimal loss of charge to exhaust-port, such a system of scavenging also reducing piston cooling-problems and misfiring associated with charge-dilution (in gasoline-engines operating under partial-charge conditions). In addition, a more general scavenging principle is enunciated and claimed, applicable to rear-compression and separately-scavenged two-stroke engines.

Abstract: The invention contemplates electronically controlled fuel-injection for a single or multiple-cylinder two-cycle internal-combustion engine wherein each cylinder has its own independent crankcase region in which to receive and compress inlet air and fuel, prior to delivery of combustible mixture to the head or combustion end of the cylinder. Fuel is injected directly into each crankcase region during only a portion of the stroke involving induced intake of air therein, i.e., during only a portion of the rise of each piston in its approach to top-center position, and while pressure within the crankcase region is relatively uniform. The time-duration of actual injection is relatively short, to enable identical injections in each cylinder, each such injection being identically timed with relation to position and displacement of its associated piston.

Abstract: A two-cycle engine of the crank chamber preloading type of the construction in which a crankcase, a cylinder head and a cylinder are clamped together by a plurality of clamping members penetrating the cylinder includes a suction port formed in a wall of the cylinder, an exhaust port formed on a side of the cylinder opposite the suction port, at least one main scavenging port disposed between the suction port and the exhaust port and directed toward the suction port, and at least one ancillary scavenging port disposed above the suction port and juxtaposed against the exhaust port. At least one ancillary scavenging passage branching from at least one main scavenging passage and communicating with the ancillary scavenging port extends around an opening for one of clamping members on the suction side.

Abstract: Two stroke engine having an exhaust port provided with a rotary type timing control valve at the upper portion thereof. The control valve is connected with a centrifugal actuator which is responsive to the engine speed so that the exhaust port is wide open under a high speed engine operation but covered at the upper portion by said control valve under a low speed operation to change the exhaust port timing.

Abstract: A two-cycle internal combustion engine includes a power cylinder, a drive piston being positioned therein. A first transfer duct extends between an auxiliary cylinder, which is supplied with carburetted air and the power cylinder and opens thereinto via a carburetted air inlet port provided on the side wall of the power cylinder or its combustion chamber. A pump crankcase, which is supplied with pure air, is connected to the power cylinder via a second transfer duct which opens thereinto via a scavenging inlet port on the side wall of the power cylinder. An exhaust port is provided on the side wall of the power cylinder. The ports are operatively arranged so that the scavenging port starts to open after the exhaust port and before the carburetted air inlet port.

Abstract: The inlet manifold for a V-6, two-cycle outboard motor engine is arranged with one inlet passage for each cylinder. The inlet passages form a V with each passage substantially in line with the cylinder it feeds, but sloping downward.

Abstract: The rotating combustible mixture in the crankcase of a two-cycle gasoline engine is scooped into the transfer duct leading to the cylinder by a plurality of vanes extending over the crankcase flywheel and in close juxtaposition thereto.

Abstract: A two cycle internal combustion engine is disclosed, which essentially comprises a cylinder consisting of a sleeve and a cylinder block housing the sleeve therein. The cylinder has a groove formed between the sleeve and the cylinder block and at least one lubricant outlet port having one end opened to the inside of the sleeve and the other end communicating with the groove. A lubricant inlet port is formed in a crankcase or an air-fuel intake passage of the carburetor connected to the crankcase, and is connected to the groove through a lubricant passage means including a check valve disposed therein.

Abstract: In a crankcase scavenged two-stroke internal combustion engine, a duct and at least one further passage extends between the crankcase chamber and the combustion chamber. There is a fuel/air mixture port leading into the duct and a pure air port leading into the duct or the crankcase chamber. The passage exits into the combustion chamber between the exit into that chamber from the duct and an exhaust port leading out of the combustion chamber. In operation fuel enters the combustion chamber in the air of the fuel/air stream entering the duct and air is additionally pushed into the combustion chamber by the downward movement of the piston through the passage and the duct. The fuel is separated from the exhaust port by a layer of air leading to better fuel consumption and higher oxidation combustion products.

Abstract: An improved two-cycle internal combustion engine with a novel intake, exhaust and piston arrangement in which a fresh charge for combustion component is advantageously transferred through the piston and all valves in the engine operate in response to changes in dynamic pressure generated within the engine. The piston includes at least one charging passage through its top surface with a pressure sensitive valve affixed to the top surface of the piston for preventing flow of a fresh charge through the charging passage in the absence of a greater pressure differential caused by the intake charge against the undersurface of the pressure sensitive valve.

Abstract: A two-cycle internal combustion engine includes a cylinder, a piston in the cylinder and a crankcase pump. The crankcase pump is divided into a first chamber and a second chamber by a membrane. At least one respective transfer passage connects each of the respective chambers to the cylinder. Inlets are provided for admitting pure air into the first chamber and for admitting carbureted air into the second chamber. Devices are provided for opening that one of the transfer passages communicating between the cylinder and the first chamber first and thereafter for opening the one of the transfer passages communicating between said cylinder and said second chamber during operation of the engine.

Abstract: An induction system for a V-type two-cycle crankcase compression engine (10) with a vertical crankshaft (14) uses two-barrel carburetors (17) with the barrels (19) horizontally adjacent to supply air-fuel mixture to the engine (10). A crankcase compartment (15) is provided for each cylinder (11), the compartments (15) being in a vertical row and surrounding the crankshaft (14). A carburetor adapter or inlet manifold (18) connects each carburetor barrel (19) to one of the crankcase compartments (15).

Abstract: A 2-cycle engine having a transfer passage communicating the crank room with the combustion chamber. An accumulation tank having a volume which is larger than the stroke volume of the piston is arranged in the transfer passage. A reed valve is arranged in the transfer passage between the crank room and the accumulation tank.

Abstract: A fuel supply system for an internal combustion engine having inlet porting and a fuel supply passage with valve means therein, the cross-sectional area lying within the outside passage walls being greater in the region of the valve means than in a region upstream of the valve means. Means are provided in the passage tending to equalize the velocity of the fuel flow through the supply passage in different regions thereof.

Abstract: A manifold system for a two stroke cycle vertical shaft internal combustion engine. A series of horizontal bores are perpendicular to the vertical shaft. A piston located in each bore establishes a combustion chamber and a fuel-air mixture supply chamber therein. A passage connects the supply chamber to the combustion chamber and a manifold system connects the supply chamber to a mixing chamber. Each mixing chamber is connected to an independent fuel supply and to a common air supply. A valve is located between the mixing chamber and the supply chamber to control the communication of a fuel-air mixture between the mixing chamber and the supply chamber. When the piston moves toward the combustion chamber a fuel-air mixture therein is compressed and at the top of the stroke ignited to produce combustion. As the piston moves toward the combustion chamber, the supply chamber expands and draws in a fuel-air mixture.

Abstract: A 2-cycle engine having a transfer passage communicating the crank case with the combustion chamber. The transfer passage comprises a first passage and a second passage. The first passage has a long length and a small cross-sectional area for causing a fresh combustible mixture to flow at a high speed. The second passage has a short length and a large cross-sectional area for causing a fresh combustible mixture to flow at a low speed. An exhaust gas recirculation device is provided for recirculating the exhaust gas from the exhaust system into the intake system of the engine.

Abstract: A 2-cycle engine having a scavenging passage communicating the crank case with the combustion chamber. The scavenging passage comprises a first passage and a second passage. The first passage has a long length and a small cross-sectional area for causing a fresh combustible mixture to flow at a high speed. The second passage has a short length and a large cross-sectional area for causing a fresh combustible mixture to flow at a low speed. In order to easily start the engine, a fuel pump is provided for directly feeding the fuel into the crank case in response to the operation of the choke mechanism when the engine is started.

Abstract: A 2-cycle engine having a transfer passage communicating the crank case with the combustion chamber. The transfer passage comprises a first passage and a second passage. The first passage has a long length and a small cross-sectional area for causing a fresh combustible mixture to flow at a high speed. The second passage has a short length and a large cross-sectional area for causing a fresh combustible mixture to flow at a low speed. The second passage is connected to the crank room via the bypass passage. A normally closed valve is arranged in the bypass passage. The valve is opened when the engine is operating under a heavy load.

Abstract: Fuel porting and passage arrangements including transfer porting and passages between the crankcase and the combustion side of the piston, together with intake porting and passage arrangements for delivering fuel to the crankcase. The transfer and intake passages include portions of regions common to both or in communication with each other in relationships providing not only for direct delivery of fuel to the crankcase but also for augmenting fuel transfer into the combustion space.

Abstract: A two-cycle internal combustion engine having a crankcase with a crankshaft rotatably mounted therein, a cylinder extending from the crankcase and having a piston slidably positioned therein with a connecting rod extending between the piston and the crankshaft, a combustion chamber defined at the end of the cylinder remote from the crankcase, an inlet channel communicating with the crankcase at one end and with an air-fuel mixture providing means at the other end, timing means to control opening and closing of the inlet channel to the crankcase, such timing means preferably being the piston skirt, a boost port extending from the inlet channel at a position between the air-fuel mixture providing means and the crankcase timing means at one end and opening to the cylinder volume at the other end, and a reed valve disposed in the boost port and oriented to control flow such that the air-fuel mixture may flow through the boost port into the cylinder but preclude reverse flow from the cylinder to the input channel.

Abstract: A single-piston or multi-piston two-stroke internal combustion engine for introducing into the working space or working spaces of the one cylinder or of the several cylinders respectively a pressurized fluid such as a gas, ambient air or a gaseous mixture or a mixture of a gaseous medium and a liquid at approximately an intermediate height of the cylinder working space between top and bottom dead center positions of the piston head surface for separating inflowing fuel-air mixture from the exiting combustion gases and for establishing a layer charge overlying the piston head. The two-stroke engine is provided with an additional inlet port for admitting this additional pressurized fluid into the cylinder working space, the inlet port being in communication with fluid supply means and optionally including an automatically pressure operated or positively actuated control member.

Abstract: A two-cycle internal combustion engine, comprising a first cylinder wherein an engine piston moves and a second cylinder wherein a movable balancing device moves, the internal faces of the engine piston and the movable balancing device delimiting the chamber of a crankcase pump, the outer face of the engine piston delimiting a combustion chamber and the outer face of the movable balancing device delimiting an auxiliary compression chamber.

Abstract: In operation of an internal combustion engine, a lamina of air is introduced into the combustion chamber to line the wall thereof, the fuel being admitted into the interior of the lamina of air. In a two-stroke engine, air entering the combustion chamber is driven by the incoming fuel mixture to form a lamina which lines the wall of the combustion chamber.

Abstract: A two cycle loop scavenging engine of the crankcase precompression type having a pair of equally dimensioned scavenging passages 14, 16 disposed in a cylinder block 10 behind an apertured cylinder line 12. The passages are symmetrically positioned on opposite sides of a vertical plane A including the cylinder axis and oriented at an angle .theta. to a plane normal to the crankshaft 17. Recessed notches 22, 23 in the lower periphery of the piston skirt 20a mate with notches 12e, 12f, respectively, in the bottom of the cylinder liner at the entrances to scavenging passages 14, 16 at the bottom of each piston stroke. The notches 22, 23 have unequal cross-sectional areas to compensate for unequal fuel mixture pressures at the scavenging passage entrances caused by the rotation of the crankweb 17a, thereby producing a more uniform fuel mixture distribution in the cylinder.

Abstract: The disclosure embraces a charge forming apparatus or carburetor embodying a fuel aspirating system and method of operation thereof wherein the charge forming apparatus comprises a body construction having a mixing passage, a fuel chamber and aperture means for delivering fuel into the mixing passage, the fuel aspirating system utilizing a jet of gas projected across the aperture means and being of sufficient velocity for aspirating fuel from the aperture means into the mixing passage effective for improved engine operation, engine acceleration purposes and efficient fuel metering.

Abstract: An internal combustion engine having at least one cylinder in which at least one piston is reciprocable; the air, or air and fuel, induction being by means of an inlet port giving rise to helical flow of air, or air and fuel within the cylinder. In one form, the inlet port is substantially tangential to the cylinder. The cylinder may have a pair of pistons therein movable in unison to adjacent top dead center positions wherein they define with the cylinder wall, an annular combustion chamber.

Abstract: Crank-chamber precompression type two cycle engines having scavenging ports connected with the crank-chamber through scavenging passages. An air supply passage is connected through a reed type check valve with at least one of the scavenging passages at the upper portion thereof so that air is introduced into the scavenging passage in the ascending stroke of piston movement and discharged into the combustion chamber in the descending stroke of the piston movement to effect scavenging. The air passage is provided with a control valve which is interconnected with the engine throttle valve so that the amount of air supply through the air passage can be controlled in accordance with the load condition of the engine operation.

Abstract: A two-cycle crankcase compression internal combustion engine having extended and specially positioned intake porting and reed-type intake valves, with the porting and valves arranged to improve various of the operating characteristics of the engine.

Abstract: A two-cycle crankcase compression internal combustion engine having extended and specially positioned intake porting and reed-type intake valves, with the porting and valves arranged to improve various of the operating characteristics of the engine.