Abstract: An improved carburetor useful for reducing emissions of small gasoline powered engines commonly used to power lawnmowers and the like has a bypass air inlet and valve for venting amounts of fresh air into the fuel/air mixture to lean the mixture prior to combustion. The enleanment of the fuel/air mixture reduces carbon monoxide and hydrocarbon emissions. The valve lags the engine load condition such that during a sudden high load condition (e.g. during acceleration) the valve remains momentarily closed to provide a rich fuel/air mixture. Likewise, during a sudden lightened load condition (e.g. during deceleration or shutoff) the valve remains momentarily open to provide a lean fuel/air mixture. Hence, emissions are reduced while engine performance and response are not compromised. In the preferred embodiment, a mechanical linkage connects the bypass air valve to the engine throttle. The lagging function is controlled by a mechanical or electrical damper.

Abstract: A metered induction two cycle engine is presented. In accordance with the metered induction two cycle engine, an aspirating cylinder (or pulsing air-charger) is connected to a combustion cylinder by a voluminous transport duct having a valve disposed therein. The valve permits flow from the aspirating cylinder and duct to the combustion cylinder and prohibits flow in the opposite direction. The duct acts as an extension of the clearance volume of the aspirating cylinder. The valve is actuated when the pressure in the duct exceeds the pressure in the combustion cylinder. Further, the aspirating cylinder leads the combustion cylinder by a fixed amount to provide a disciplined flow of mixture (i.e., air and fuel) into the combustion cylinder.

Abstract: A heating device for injected fuel in an internal combustion engine is disposed at an upper wall of an intake port. The heating device includes a casing and a plurality of fins integrally connected to a lower plate of the casing. A heater is disposed between the intake port and the casing. The fins are arranged to downwardly extend from said supporting member and along the injected direction of the injected fuel. Therefore, the atomization of the injected fuel is accelerated by the heating of the heating device.

Abstract: A fuel supplying device for an internal combustion gasoline engine in which, a loss of air pressure due to the heater is reduced, the heater efficiency is improved, and which is applicable to a multi-point injection system. The fuel supplying device for an internal combustion gasoline engine includes a fuel heating heater 3 provided in the suction pipe 6 of the engine in such a manner that it is extended along the inner wall of the suction pipe 6, so that a loss of air pressure is reduced. One of the plurality of sprays of fuel jetted by a multi-spray type fuel injection valve 7 is applied to the heater, so that the heater efficiency is improved. The fuel injection valve 7 is provided for each of the cylinders of the engine.

Abstract: In a state in which the engine is unloaded and the number of engine rotation is low, an overlap period of time during which the intake valve and the exhaust valve are both open is extended during the cold time, as compared with during the warm time. The extension of the overlap period of time causes gases remaining in the cylinders to increase, thereby making the burning of the fuel slow and elevating the temperature of the exhaust gases to thereby elevate the temperature of the cylinder head of the engine. A variation in the number of engine rotation, particularly a decrease in the number of engine rotation, resulting from the increase in the residual gases can be prevented by increasing the amount of intake air. Further, the temperature of the cylinder head can be elevated due to an increase in the amount of the supplied fuel resulting from the increase in the amount of the intake air.

Abstract: In a cylinder sleeve assembly comprising a plurality of cylinder sleeves whose adjacent cylindrical peripheral walls are coupled to each other, a plurality of sink mark inhibiting projections biting into the cylinder sleeve assembly during casting a cylinder block are provided in each of valley-like areas of an outer peripheral surface of the cylinder sleeve assembly which are located on opposite sides of a coupled portion of the adjacent peripheral walls. Thus, the adhesion between the cylinder barrel assembly and the cylinder sleeve assembly is enhanced. In addition, the adhesion is further enhanced by providing a predetermined inclination to each of the sink mark inhibiting projections.

Abstract: A system for providing an air-fuel vapor mixture to an engine for improving completeness of combustion and also reducing emissions. The system includes a vaporizer within which a series of baffles are disposed such that air and fuel pass along a tortuous passageway defined within the vaporizer. Exhaust gases provide heat to the vaporizer, and as air and fuel pass along the passageway of the vaporizer, a homogenous air-fuel vapor mixture is produced, with the homogenous mixture exiting the vaporizer being supplied to the engine by way of an adapter plate assembly. When used with a carburetor, the adapter plate is disposed between the carburetor and the engine.

Abstract: An opposed piston internal combustion engine comprises an output shaft, at least one cylinder, at least one pair of first and second opposed pistons slidable in said cylinder, a first cam connected to the output shaft and a first cam follower assembly connecting the first piston to the first can, a second cam connected to the output shaft and a second cam follower assembly connecting the second piston to the second cam, an intake valve comprising a slide valve obtained by first piston covering and uncovering an intake port provided in a sidewall of the cylinder at a first end of the cylinder, and an exhaust valve comprising a slide valve obtained by the second piston covering and uncovering an exhaust port provided in the sidewall of the cylinder at a second opposite end of the cylinder, the first and second cams cooperating to provide a cycle of relative movements between the pistons and of valve actions giving rise to five cycles of (i) intake, (ii) compression, (iii) expansion, (iv) exhaust, and (v) return

Abstract: The invention is directed to a starting device for manually starting an internal combustion engine and especially a two-stroke engine. The starting device comprises essentially a clutch drum which is actuated by a pull rope for imparting rotation to a catch which coacts with a clutch element of the engine shaft. The starting device maintains within limits the effects of stronger fluctuations of the reaction torque of the engine shaft on the hand of the operator. This is achieved in that the clutch drum and the carrier of the catch are configured as separate parts and are connected by an elastically-deformable entraining element which takes up the force peaks of the reaction torque.

Abstract: An intake flow booster is provided for insertion between the carburetor and intake manifold of an internal combustion engine which includes a series of downwardly depending tubes having an internal frustro-conical shape. The fuel/air mixture leaving the carburetor passes through a well in the manifold plate and into the manifold tubes whereby the mixture flows more efficiently to the engine providing a higher performance and greater horsepower.

Abstract: A single piston internal combustion engine is described that produces two power impulses per revolution of the crankshaft, precise mechanical balance, zero side thrust upon the piston, and purified exhaust gas. The lubrication oil is isolated from contamination by blowby and fuel dilution. Total engine cooling is obtained from the lubrication oil. The engine is free from shock loads as it is cushioned by continuously compressing gas in preparation for the next combustion event. The engine is uniflow-scavenged utilizing piston pumps whose fresh air intake is controlled by rotary valves. The piston pumps possess compact aftercoolers used in combination with supercharging. The exhaust header assists in silencing the engine and removes fluctuations in exhaust pressure. A computer-aided specialized mechanical balance methodology is disclosed that obtains counterbalance weights to optimally reduce engine shaking forces.

Abstract: A four valve, double overhead camshaft open chamber diesel engine (10) has a combustion chamber (44) formed in part by a piston (18). The piston has an upper surface with recessed lobes (20) and (22). Each recessed lobe functions has a valve pocket for the intake and exhaust valves (32) and (42). A multihole fuel injector (70) has a discharge orifice (72, 74) angled toward the center of each lobe to spray separate fuel plumes into the respective recessed lobes (20, 22).

Abstract: An internal combustion engine has a carburetor for mixing fuel with air entering through an inlet. A heat exchanger is mounted onto the carburetor air inlet so that heat from the heat exchanger is conducted to the carburetor housing. The heat exchanger has a plurality of channels through which air from an air cleaner pass on the way to the carburetor. An electric heating device attached to said heat exchanger and a first thermostat controls the electric heating device to raise the temperature of the heat exchanger when the fuel-air mixture falls below a given temperature. A second thermostat senses the temperature of the heat exchanger and prevents the temperature from exceeding a level at which a user's skin will blister if the exchanger is touched accidentally. In cold operating environments, the heat exchanger assembly raises the temperature of the air above the dew point, thus effectively lowering the relative humidity.

Abstract: The invention is directed to a two-stroke internal combustion engine for handheld portable tools such as a motor-driven chain saw with the engine having a piston guided in a cylinder. The base of the piston is rotationally symmetrical and delimits a combustion chamber. An injection valve is mounted in the cylinder wall opposite an exhaust opening for exhaust gases. The injection valve injects fuel toward the piston base at an angle of less than 90.degree.. At least one overflow opening is arranged in the cylinder wall between the exhaust opening and the injection valve. Combustion air flows in through the overflow opening with the downward movement of the piston. The injection jet is directed opposite to the flow direction of the entering combustion air. The injection jet is directed for the most part to the half of the piston base which is disposed away from the exhaust opening and the injection opening is the last opening to be closed by the piston travelling toward top dead center.

Abstract: An exhaust gas burner reactor which comprises a burner apparatus having a combustor tube which extends axially in a spaced relationship to an exhaust gas conduit. The combustor tube has a first, base end having fuel and air inlets and a mixing chamber therein, and a second combustor end having a combustor chamber and outlets for ejecting burning fuel and air into the exhaust gas conduit. The combustor assembly is oriented so as to locate the burner outlets upstream of the first end so that heated exhaust gas/burner output mixture passes through an exhaust reactor defined between the combustor tube and the exhaust gas conduit. The reactor aids in the combustion of unreacted fuel components in the exhaust gas.

Abstract: The present invention discloses a means for limiting the pressure within the induction system of an internal combustion engine having a flexible elastomeric sealing wall disposed between components of the intake. When internal pressures reach a predetermined limit, the wall is subject to elastic deformation to thereby vent the pressure increase within the induction system to the exterior thereof. Rates of pressure rise and peak pressures are thereby lowered. Return of normal system pressure levels operate to reseat the sealing wall enabling continuation of engine operation.

Abstract: In a two-stroke internal combustion engine with at least one cylinder opeg into an exhaust passage with a diffuser-type flare whose shape is determined mainly by that of the lower contour, an optimum flow pattern in the exhaust passage is obtained by providing the exhaust passage with a nozzle-like throat in the immediate vicinity of the cylinder, which is formed by the lower contour and is followed by the diffuser-type flare, either immediately or at a distance.

Abstract: A control system for an internal combustion exhaust gas heater provides air and fuel to the heater in appropriate proportion to be rapidly ignited therein upon activation of the control system. When flame is present in the heater, the proportion of air and fuel is adjusted to provide maximum heat energy from the heater to the exhaust gas for a predetermined period of time.

Abstract: A heating system using a heating device 1 with a positive temperature coefficient thermistor 10 (PTC) is disclosed for the purpose of warming a carburetor/throttle body of an internal combustion engine and a timer device 20 using the PTC 10 for its control.

Abstract: A fastener is provided which is adapted to be at least partially embedded within a intake manifold. The fastener comprises a first threaded section and a second section. The second section has a first end part defining a shoulder for making contact with a first portion of a mold during formation of the workpiece and a second end part having an outer end face for making contact with a second portion of the mold during formation of the workpiece. The second section further includes a crush-boss extending outwardly from the outer end face for contacting the second portion of the mold and thereby ensuring that the second section of the fastener is compressively engaged by the first and second portions of the mold during formation of the workpiece.