Abstract: Several embodiments of arrangements for blowing condensation from a horizontally extending portion of a transfer passage of a two-cycle internal combustion engine into the combustion chamber for improving stability of running, particularly under idle, low speed, acceleration and deceleration conditions.

Abstract: A two-cycle crankcase compression internal combustion engine for use in an outboard motor that facilitates the use of low quality fuels by providing a carburetor that discharges fuel directly into one of the transfer passages of the engine. The transfer passages and carburetors are disposed so that the carburetors may extend horizontally and permits the use of a plurality of carburetors, one spaced above the others.

Abstract: A two cycle crankcase scavenged internal combustion engine having an exhaust gas recirculation system. Exhaust gas from the coolest part of the exhaust muffler is recirculated back to the crankcase in a controlled discrete charge on each cycle of the engine. A recirculation port extends through the cylinder sidewall and is opened briefly during the compression stroke of the piston to thereby enhance vaporization of the fuel and increase velocity of the scavenging air-fuel mixture into the combustion chamber.

Abstract: An internal combustion engine cylinder assembly comprising an elongated cylinder having substantially vertically disposed interior walls defining an elongated firing chamber therein; piston means housed within the firing chamber and adapted for vertical reciprocation within the firing chamber; gas inlet channels in the lower portion of the firing chamber; a crankcase housing having a gas compression chamber disposed therein; a reed valve means pivotally secured to the inner walls of the gas compression chamber and adapted for passing fuel/air mixtures into the gas compression chamber upon the depressuring thereof; a cylinder closure means positioned at the upper end of the cylinder defining the upper end of the firing chamber and being provided with exhaust gas valve means, adapted for cyclic opening and closing to alternatively permit the removal of exhaust gases from the firing chamber and the pressuring to the fresh fuel/air mixtures in the firing chamber; fuel ignition means for igniting a compressed fuel

Abstract: Several embodiments of charge forming devices including improved accelerating pumps wherein the discharge of fuel from the accelerating pump is extended in time through the use of an accumulator chamber. In addition, the accelerating pump has an upstream and downstream discharge port. The accumulator chamber is also adapted to discharge fuel into the induction passage during extreme deceleration so as to improve engine running and prevent stalling under these circumstances.

Abstract: An engine comprises a combustion chamber and a fuel transfer passage having a fuel outlet port communicating with the combustion chamber. A primary fuel delivery system communicates with the combustion chamber and introduces fuel from the fuel source into the combustion chamber. The engine further comprises a fuel pump which is adapted to be connected with a source of fuel and a fuel return line having a first end communicating with the source. A mechanism selectively controls the communication of the fuel pump with either the fuel return line or the fuel transfer passage, so that an enriched flow of fuel can be selectively supplied to the combustion chamber prior to and after starting.

Abstract: A lubricating oil supply controller for a two-cycle engine is disclosed, wherein a lubricating oil is supplied to an intake air passage separately from fuel without mixing in advance the lubricating oil with fuel which is to be supplied to an engine. In this controller, a non-contacting type electrometer provided at a carburetor detects the fuel supply flow rate as a voltage. Thus detected voltage value is transmitted to a computer as a digital input through an analog-to-digital converter. This computer operates calculation by serving the input as a parameter and transmits a desired digital control signal to a step motor. The step motor is operated in response to the digital control signal and control a lubricating oil injection valve. In this way, the lubricating oil in its proper flow rate according to fuel supply flow rate is supplied to the engine.

Abstract: A two-cycle engine with an intake port extending perpendicularly to a crankshaft, wherein the intake port is directed substantially parallel with a tangential line a crank web defines at its top point on the side of a cylinder. A cylinder skirt portion fronting an end opening of the intake port at the cylinder side has a part thereof cut, while keeping its length in the axial direction of the cylinder. The two-cycle engine further includes a rotary valve mechanism having a rotary valve cover covering a rotary disc, the rotary valve cover being formed with an intake hole, and an intake tube connecting the intake hole to a carburetor, and the intake tube is integrally jointed to the intake hole.

Abstract: A suction device suitable for use with a two-cylinder internal combustion engine including a second suction port formed at a wall of at least one of the pair of cylinders in a position in which it is opened and closed by a piston in the cylinder, and a second conduit allowing the second suction port to communicate with a carburetor therethrough.

Abstract: A reed valve includes a reed member fixed to a valve body and a stopper member which is fixed at one end thereof to the valve body together with the reed member. The stopper member is constituted by a flat plate-shaped member which is curved outwardly from the one end to its free end, and a lump member which is secured to the surface of the flat plate-shaped member on the side thereof which is remote from the reed member. The lump member has a shape which is substantially coincident with the shape of a space which is formed on the downstream side of the reed valve and does not virtually take part in the flow of intake. The lump member is disposed within the space.

Abstract: A motorcycle having a V4 crankcase compression, two-cycle internal combustion engine having an improved, compact induction system. The induction system for the cylinders of one bank discharges directly into the crankcases of those cylinders and is fed with a pair of carburetors through an induction system which induction system is positioned at least in part in the area between the banks of cylinders. The carburetors are disposed at least in part at the sides of the engine. The cylinders of the other bank are supplied with a charge indirectly to their crankcases through a similarly configured induction system. The induction system of one bank has its charge forming devices positioned above the charge forming devices of the other bank.

Abstract: In a two cycle internal combustion engine (2) wherein heavy fuel ends accumulate in lower portions of the crankcase (8), recirculation means (36, 38) are provided for variably recirculating the heavy fuel ends back into the crankcase only at higher engine speeds for subsequent combustion. The heavy fuel ends are collected in a reservoir (36), and held therein at idle, to minimize engine smoke. The heavy fuel ends are released from the reservoir at higher engine speed for recirculation through a delivery line (40) which is selectively exposed by a throttle valve (24) to crankcase vacuum only at higher engine speed, whereby the heavy fuel ends are sucked from the reservoir through the delivery line and carburetor throat (26) into the crankcase.

Abstract: Method and apparatus for supplying fuel to an internal combustion engine, which engine performs strokes for suction, compression, expansion and exhaust in sequence. The method comprises alternatingly supplying fuel to the engine and suspending the fuel supply to the engine in successive suction strokes. In a heavy load range of operation of the engine, the fuel can be supplied in each of the successive suction strokes. Various different embodiments of the apparatus for performing the above method are disclosed.

Abstract: Several embodiments of heating devices for heating the charge of a two-cycle engine before it passes the gap of the spark plug at the time of ignition. The heating devices permit the use of low quality fuel such as kerosene or alcohol without some of the problems normally attendant with engines running on this type of fuel.

Abstract: The internal combustion engine includes a carburetor having an air induction passage communicating with the engine combustion chamber and a throttle valve mounted inside the induction passage for pivotal movement between an idling speed position and a range of high speed positions, a primary fuel delivery system including a fuel pump for supplying fuel to the carburetor during normal engine operation, and a secondary fuel delivery system for supplying a flow of enrichment fuel to the engine combustion chamber, independently of the primary fuel delivery system, during periods of rapid engine deceleration.

Abstract: A two cycle internal combustion engine (10) has at least two cylinders (12, 13) which fire alternately with pressure in one crankcase (17 or 18) at the time there is vacuum in the other. Supplemental fuel flow passages (36, 41) extend from each crankcase and are joined at a common passage (46) connected to the float bowl (30) of the carburetor (20). A normally closed control valve (48) is disposed in the common passage. When the engine is to be started, the control valve is opened so that fuel enters the supplemental and common passage. Initial rotation of the crankshaft (16) causes pressure in one crankcase to force fuel toward the other crankcase, which has vacuum. Further crankshaft rotation reverses the pressures so that fuel is then forced toward the opposite crankcase. Continued engine operation with the control valve open causes alternate fuel flow reversals together with pressurized alternate fuel injections into the respective crankcases, which are independent of the throttle setting.

Abstract: An induction system for a four-cycle internal combustion engine that improves charging efficiency, power and torque at idle and low speed. A check valve is provided in the intake passage for precluding reverse flow under these running conditions. In addition, a plenum chamber is provided that communicates with the intake passage downstream of the check valve for improving power and torque throughout the entire load and speed range of the engine.

Abstract: A stratified-charge two-stroke cycle scavenged spark-ignition engine 1 includes a piston (2) reciprocal in a cylinder (3) between a combustion chamber 4 and a crankcase (5). A carburetor (17) is mounted to the crankcase substantially coaxially with the piston to afford narrow engine design. An elongated scavenging air passage (14) extends between the crankcase and the combustion chamber and has a length substantially greater than that of a fuel-air transfer passage (7), and the height of piston (2), to reduce fuel mixture in the scavenging air passage and afford substantially only air at an air inlet port (16), which port is between fuel-air mixture inlet port (8) and exhaust port (13).

Abstract: A crankchamber precompression type two-cycle internal combustion engine including at least one cylinder assembly, each cylinder assembly including a stepped cylinder constituted by a minor diameter cylinder portion and a major diameter cylinder portion, a stepped piston received in the stepped cylinder and constituted by a minor diameter piston portion and a major diameter piston portion adapted to be fitted in the minor diameter cylinder portion and the major diameter cylinder portion respectively, a crankchamber connected to the major diameter cylinder portion, a working chamber defined between the minor diameter cylinder portion and the minor diameter piston portion, and a sub-intake chamber defined between the major diameter cylinder portion and the minor diameter piston portion.

Abstract: A stratified-charge cross-flow scavenged two-stroke cycle spark-ignition engine (1) includes a piston (2) having a raised crown (6) with a baffle (7) and chamfered sides (8, 9) and reciprocal in a cylinder (3) between a combustion chamber (4) and a crankcase (5). Transfer passage structure is disclosed wherein a pair of elongated scavenging air passages (17, 18) extend between the crankcase and combustion chamber on opposite sides of a shorter fuel-air transfer passage (11). A pair of scavenging air inlet ports (20, 21) in the combustion chamber are adjacent the fuel-air inlet port (12) therebetween and substantially distally opposite the exhaust port (16). The scavenging air inlet ports face the baffle at its edges along the chamfered sides of the piston crown.

Abstract: A crank-case pre-compression type 2-cycle engine internal combustion has an intake opening formed in the wall of a crank case and provided with a reed valve therein, and a carburetor disposed at a rearward offset from the intake port. The carburetor is connected to the inlet port through a joint-pipe. The joint-pipe has a mixture passage formed therein, an intermediate contracted portion and a partition plate extending along the axis of the mixture passage. The portion of the mixture passage near the outlet opening thereof is curved to cross the intake port substantially at a right angle to the latter.

Abstract: A two-cycle internal combustion engine having reed valves in the fuel/air supply system is provided with an element in the flow path of the fuel/air into the reed valves, which element is shaped and positioned to promote uniformity of flow of the fuel/air mixture in the flow passage.

Abstract: An engine comprising one pair of scavenge ports alternately covered and uncovered by a piston, a richer air-fuel mixture and a leaner air-fuel mixture being separately fed into the cylinder from the scavenge ports, the richer air-fuel mixture flowing into the cylinder towards the inner wall thereof, located opposite the exhaust port, and the leaner air-fuel mixture flowing into the cylinder so that it overlays the richer air-fuel mixture.

Abstract: Disclosed herein is an internal combustion engine comprising a crankcase, a cylinder extending from the crankcase and having an inlet port, a piston located in the cylinder, a transfer passage located between the crankcase and the cylinder inlet port, a fuel pump adapted to communicate with a source of fuel for normal operation, a carburetor having an air induction passage communicating with the crankcase and including a venturi, which carburetor also includes a float bowl communicating with the fuel pump and a high speed nozzle communicating between the float bowl and the venturi, a low speed fuel nozzle communicating with the transfer passage adjacent the inlet port, and a fuel line communicating between the float bowl and the low speed nozzle and including therein check valve means preventing flow from the transfer passage to the float bowl and permitting flow from the float bowl to the transfer passage, which fuel line also includes fuel flow metering means.

Abstract: Several embodiments of fuel injection controls for two-cycle crankcase compression internal combustion engines. In each embodiment, the fuel injection is controlled by measuring the amount of air inducted through measurement of the pressure generated in the crankcase. In each embodiment, abnormal pressure variations in the crankcase not due to the amount of air inducted are eliminated by measuring the pressures at predetermined crankshaft angles. In some embodiments, this is done through the use of a valving arrangement and in other embodiments, this is done electronically.

Abstract: Disclosed herein is an outboard motor comprising a cylinder, a crankcase extending from the cylinder and including an upper portion having a bearing and a lower portion having a drainage outlet, a transfer passage extending between the cylinder and the crankcase, a drains return inlet in one of the cylinder and the transfer passage, a fuel supply system including an inlet manifold communicable with the cylinder and having a drains outlet and a carburetor communicating with the inlet manifold and having a drainage outlet, an overboard drain, and a valve and conduit system selectively operable for communicating the overboard drain with each of the manifold drains outlet, the crankcase drains outlet, and the carburetor drainage outlet, for communicating the crankcase bearing and the drains return inlet with the manifold drains outlet and the crankcase drains outlet, and for closing the carburetor drainage outlet.

Abstract: The invention relates to a method and to a port-controlled two-stroke internal combustion engine in which the cross-sections of the intake and outlet are so constructed in the direction of the longitudinal axis of the cylinder that in the case of an upward or downward movement of the piston, the noise-generating intake and outlet pressure gradients and amplitudes are reduced by the gradual opening of the particular intake and outlet, the piston lower edge and intakes having special constructions.

Abstract: A method and apparatus for improving the performance and efficiency of a two-cycle internal combustion engine are described wherein the backflow combustion mixture gasses are captured at the reed valve and directed through a uni-directional passageway and injected back into the incoming air stream in the incoming air boot ahead of the carburetor so that the proper air-to-fuel mixture may be maintained by the carburetor. Recirculation of the backflow combustion mixture gasses as mentioned above increases the performance and the efficiency of a two-cycle internal combustion engine.

Abstract: A reciprocating piston internal combustion engine having an intake air system, an exhaust gas system, and an injection pump. To lubricate the injection pump, the latter can communicate with the lubricating-oil system of the internal combustion engine; the injection pump conveys a fuel having a low boiling point. A vaporizer is provided, the input side of which can communicate with the lubricating-oil return line of the injection pump, and the output side of which can communicate with the lubricating-oil system of the internal combustion engine and with the intake air system. The vaporizer serves for purifying the lubricating oil of fuel constituents which have a low boiling point and which contaminated the lubricating oil as a result of unavoidable leakages within the injection pump.

Abstract: A fuel injection control method and system for a crankcase compression two cycle engine wherein the amount of fuel discharge is controlled by the pressure in the crankcase.

Abstract: A pump supplies pressurized lubricant to an internal combustion engine from an external reservoir through a closed loop system. Delivery channels extending through the crankshaft, connecting rod and other components, supply the pressurized lubricant to the several areas of relative movement. Return channels, extending through the components, conduct lubricant from the several areas to the reservoir. Fuel-air mixture from a carburetor enters the crankcase through the open end of the crankshaft and moves through ports within the several cylinders to the respective combustion chambers. Selected ports are sequentially closed by a valve plate carried by the crankshaft. Incomplete products of combustion are exhausted into an auxiliary exhaust outlet for recycling with the fuel-air mixture. Retainer members engaging the spark plugs assist in dissipating heat therefrom.

Abstract: A 2-cycle opposed cylinder internal combustion engine of simultaneous ignition type for portable machines such as grass trimmer. Two cylinders are provided at their same sides with intake ports and exhaust ports. In each cylinder, the intake port and the exhaust port are arranged in a side-by-side relation in the direction of axis of the cylinder. Namely, exhaust port which is heated to high temperature is arranged near the intake port which is cooled during the operation of the engine. In consequence, the temperature of the portion around the exhaust port is lowered while the temperature of the portion around the intake port is raised to uniformalize the temperature distribution in the cylinder to eliminate various problems attributable to non-uniform temperature distribution in the cylinder.

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 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: Two-cycle internal combustion engines are disclosed incorporating intake and transfer ports and passages, and including passages means in the cylinder wall interconnecting the intake tract and a transfer passage in a region above the piston when the piston is in bottom dead center position.

Abstract: A two cycle engine having piston controlled inlet and exhaust ports is provided with a secondary one-way valved air fuel mixture passage to the combustion chamber adjacent the spark plug.

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: Several embodiments of induction systems for internal combustion engines that improve charging efficiency over a widespread range, particularly at the lower speeds of the engine. Each embodiment includes a plurality of plenum chambers each of which communicates with the intake passage of the engine between the throttle valve and the served chamber. In one embodiment, the plenum chambers communicate with the induction system through separate branch passages. In other embodiments, the plenum chambers communicate with the induction system through each other.

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: A two-stroke cycle gasoline engine including at least one two-stroke cycle power cylinder-piston assembly incorporating uniflow scavenging and two horizontally opposed pistons and two crankcases to perform crankcase compression, and at least one scavenging pump cylinder-piston assembly of the reciprocating type, wherein the power assembly has main and additional scavenging ports; the pump assembly has a first delivery port which supplies scavenging mixture to one of the crankcases of the power assembly and a second delivery port which supplies scavenging mixture directly to the additional scavenging port, the main scavenging port being supplied with scavenging mixture from the crankcases, wherein the top dead center of the pump assembly is, as viewed in the crank angle diagram, between the bottom dead center and the main scavenging port closing phase point of the power assembly, and wherein a means is provided so as to interrupt the supply of scavenging mixture from the first delivery port of the pump assembl

Abstract: A two-cycle internal combustion engine includes a crankcase extending from a cylinder and supporting a horizontally extending crankshaft, a piston mounted for reciprocative movement in the cylinder along an axis generally perpendicular to the crankshaft axis, an air and/or fuel inlet on the crankcase including a flange disposed in a first plane extending generally parallel to the crankshaft axis and perpendicular to the piston axis and having a major axis extending transversely of the crankshaft axis, and a manifold having an outlet flange which is disposed in the first plane and has a major axis extending generally parallel to the major axis of the crankcase inlet flange and further having an inlet flange disposed in a second plane extending generally vertically and having a major axis which extends generally horizontally and is angularly related at a substantial angle to the major axis of the crankcase inlet flange.

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 invention relates to an improvement in a two-stroke internal combustion engine with opposed cylinders of different diameters which communicate by way of a combustion chamber of bell configuration for radially stratifying the rich mixture charge fed tangentially into the minor cylinder and the air charge fed into the major cylinder.

Abstract: An air and fuel induction system for a two cycle engine having two adjacent horizontal cylinders positioned aligned one above the other and each having a separate closed crankcase includes a single horizontally positioned carburetor having a single metering system for supplying an air and fuel mixture to both cylinders. An induction passageway for each cylinder connects between the carburetor and each crankcase. Each induction passageway has an opening at about the same elevation and each opening has about the same cross sectional area. A reed valve is positioned adjacent the carburetor throat and at the entrance to each of the induction passageways. The reed valve includes at least one flat reed positioned directly across and closing the opening to each of the induction passageways.

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: A motorcycle engine having a V-shaped cylinder arrangement in which a space is defined between the fore and aft cylinders. Carburetors for the fore and aft cylinder are disposed in the space between the cylinders and an air filter is located behind the engine. The motorcycle has a frame which is formed with an inside cavity connected with the air filter and the carburetors so that the inside cavity constitutes a part of the intake passage.

Abstract: A method for operating a two-cycle internal combustion engine wherein in the scavenging stroke the air-fuel mixture charged into the cylinder forms a stratum adjacent to a piston and the stratum of the air-fuel mixture is made into contact with the stratum of the residual gases remote from the piston. Alternately, in the scavenging stroke the rich mixture is first charged into the cylinder immediately above the piston and then the lean mixture is charged into the cylinder immediately above the piston so that the strata of the lean and rich mixtures and the residual gases may be formed in the order named from a portion close to the piston within the cylinder. The decomposition of part of the air-fuel mixture or the rich air-fuel mixture is caused by the heat contained in the residual gases so that the chemically activated radicals are produced.

Abstract: In a water cooled, two-cycle, crankcase compression, V-6, outboard motor engine, cooling passages are provided on the outside of the V, near the crankcase. The engine uses an exhaust manifold cooling jacket to preheat the coolant before supplying it to the engine block cooling passages.

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.