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 fuel injection pump in which a relief channel is formed which communicates with the pump working chamber and is arranged to be blocked by a valve means, associated with a valve actuating means responsive to a pressure varying with engine r.p.m., during starting of the engine so that the fuel injection quantity is increased. Thus, improved starting characteristics of the engine can be obtained. Said relief channel may comprise a first channel communicating with the pump working chamber, and a second relief channel which has a portion thereof extending in the pump plunger to terminate in an outer periphery of the bottom end of said plunger and is so disposed as to communicate with the pump suction chamber after a predetermined delivery stroke length or prestroke has been executed. Communication between said first and second relief channels is adapted to be interrupted by said valve means at less than a predetermined engine r.p.m.

Abstract: An exhaust gas recirculating device in which the intake mixed fuel gas passageway is surrounded by a double wall tube which defines a ring shaped space therebetween. Recirculating exhaust gas is introduced into the ring shaped space to heat the inner tube of the double wall to ease vaporization of the wall stream of fuel and the exhaust gas is blown out from a narrowed outlet of the space so as to well mix the fuel gas mixture and the recirculating exhaust gas.

Abstract: An exhaust gas recirculation system for an internal combustion engine employs a vacuum actuator for a control valve in the exhaust gas recirculation passageway. A suction conduit to the actuator contains a magnetic valve for venting the suction conduit to atmosphere. The operating means for the magnetic valve includes a vacuum switch responsive to suction pressure in the engine intake passage modified by atmosphere pressure compensation means. A second magnetic valve responsive to engine speed also vents the suction conduit to atmosphere.

Abstract: A heater for an air-fuel mixture having a heating element of a positive temperature coefficient resistor comprises a pair of metallic thin cylinders of different sizes each having outward flange portions at least at one end combined with each other as a double cylinder; a plurality of positive temperature coefficient resistors arranged between said inner and outer cylinders with springs for pressing the positive temperature coefficient resistors to the inner cylinder wall; an electric insulator plate inserted between the outward flange portions of said inner cylinder and the outward flange portions of said outer cylinder; a fixing means anchoring between said outward flange portion of the outer cylinder and said outward flange portion of the inner cylinder for fixing integrally with electric insulator plate; an electrically insulating material inserted between an inner end portion of the inner cylinder and an inner end portion of the outer cylinder for spacing between said inner end portion of the inner cylin

Abstract: The present invention relates to a four-cycle internal combustion engine in which a strong swirl can be generated within the combustion chamber through the directionality of the mixed gas supplied from the main suction path and the injection of a gas from the sub-suction path, and a heavier EGR than before can be carried out without detracting the engine performance, and NOx generation can be substantially reduced by EGR alone. In time of idling when a heavy EGR is needless, the gas injection from the sub-suction path is controlled to prevent a misfiring.

Abstract: An improvement in a fuel metering system having an engine, carburetor, a fluid fuel at super atmospheric pressure and a throttle for controlling the speed and power, the improvement being characterized by a fuel pressure regulator and an obstruction and regulator for controlling pressure drop across the obstruction proportional to the pressure drop across the butterfly within the carburetor so as to obtain a substantially constant fuel-air ratio being fed to the engine regardless of the carburetor demand. Also disclosed are a variety of means for accomplishing the obstruction and regulation of pressure drop thereacross, as well as the improved regulators, per se.

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: An exhaust gas recirculation system for an internal combustion engine employs a first control valve in an exhaust gas introduction passageway, a second control valve in an air conduit connecting the engine intake passage to atmosphere, and a regulating valve responsive to differential vacuum intensities for operating vacuum-responsive actuators for the control valves. A recirculation stop valve vents to atmosphere the actuator for the second control valve in response to an engine operating condition, to stop recirculation of exhaust gas.

Abstract: A flexible coupling having a rotatable drive and driven member. Each member has a pair of diametrically opposed lugs secured thereto. A floating member having four equally spaced peripheral grooves is disposed between the drive and driven member. Tilting elements contact each lug of the drive and driven members with two sides of each respective groove of the floating member.

Abstract: Several embodiments of exhaust gas recirculation systems for internal combustion engines. In each embodiment an arrangement is provided for cooling at least a portion of the recirculated exhaust gases during at least some running conditions prior to reintroduction into the combustion chamber. In one embodiment, the cooled exhaust gases are mixed with uncooled exhaust gases to provide the desired temperature of exhaust gas recirculation. In another embodiment, the exhaust gases are cooled by a fan that is operated in response to the engine running condition. In addition, a device is incorporated for controlling the cooling of the exhaust gases in response to engine temperature.

Abstract: An internal combustion engine includes a power cylinder, a power piston reciprocating therein and an auxiliary piston reciprocating within an auxiliary cylinder. Passages connect the upper end of the auxiliary cylinder to a combustion chamber and a source of air. Rotating valves or conventional reciprocating valves control the intake of an air/fuel mixture into the supercharging cylinder, transfer the mixture to the main or power cylinder and exhaust combusted gases from the main cylinder. An expansion chamber is placed in communication with the power cylinder at the beginning of the power stroke to permit an overcharge of air/fuel mixture to be transferred to the combustion chamber.

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: Initially the engine operates normally with the exhaust gases preheating the air from the air cleaner intake, said air then being pressurized prior to it entering the carburetor. As the coolant temperature increases, heated coolant flows through a double heater coil within a chamber in which gasoline is contained. This vaporizes the gasoline and increases its pressure within the chamber until a predetermined pressure is reached which actuates a pressure switch controlling a solenoid valve which in turn by-passes the carburetor and allows pressurized fuel vapor to mix with preheated air under pressure thus operating the internal combustion engine on the cracked fuel and hot air mixture. When the engine is shut down the system returns to the original condition ready for the next starting cycle.

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 power turbine rotor drive shaft has a flanged end connected to a turbine rotor disc supported by a rotor bearing housing so as to be rotatably supported by a turbine rotor bearing assembly at one end of the shaft and including a second splined end thereon coupled to a shaft extension supported at one portion thereof by a roller bearing shaft assembly and wherein the shaft has a predetermined fundamental bending vibration mode between the rotor bearing assembly and the shaft bearing assembly and wherein an insert sleeve is shrunk-fit within an inside diameter of the shaft to stiffen the shaft so as to increase the fundamental bending vibration mode of the resultant composite shaft without excessively increasing the weight of the composite shaft.

Abstract: An exhaust gas recirculation control system for an internal combustion engine comprises a pressure detector responsive to exhaust gas pulsations for detecting pressure in an exhaust gas recirculation passage which is closely associated with an exhaust gas recirculation flow rate to detect any deviation of the detected pressure from a desired value previously determined depending upon the engine operating conditions and thereby to control the exhaust gas recirculation flow rate in a feed-back control so as to eliminate any deviation in pressure.

Abstract: A method of rigidifying the normally flexible joint of a flexible torque transmission coupling without the use of support arbors. The joint of the coupling is axially compressed to provide both angular and axial rigidity of the coupling prior to balancing in a conventional manner. The method of compressing the joint may be adapted to accommodate the particular coupling being balanced.

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: This invention relates to a computer controlled fuel system for an internal combustion engine including a low profile carburetor for permitting engine operation on very lean fuel/air ratios without sacrificing engine performance during critical engine operations such as start up, warm-up and acceleration. The low profile carburetor provides a single point source fuel dispersion and includes one or more throttle controlled, sliding plates for increasing fuel entrainment at low engine speeds by increasing the velocity of the airstream flow through the carburetor just before the dispersion point and by maximizing the lateral distance between the point of fuel dispersion and the carburetor airstream. The computer controlled system includes various threshold circuits for providing additional fuel and/or water injection into the carburetor airstream upon detection of predetermined engine conditions.