Abstract: A variable exhaust resonance chamber valve system for internal combustion engine. The engine includes a cylinder having an exhaust port with an axial extent along the axis of the cylinder structure. An exhaust passage having a resonance port extends from the exhaust port to exhaust the engine. A resonance chamber extends from the resonance port and communicates with the exhaust passage through the resonance port. A port valve is adjustable between a second position, in which the port valve exposes the exhaust port throughout its axial extent and occludes the resonance port, and a first position, in which the port valve restricts the axial extent of the exhaust port and exposes the resonance port. A valve control module is connected to the port valve and functions to adjust the port valve between first and second positions in response to engine conditions. At low speeds and low output conditions, the valve is in its first position.

Abstract: Crankcase scavenged internal combustion engine (1) of two-stroke type, intended for a working tool, preferably a chain saw or a trimmer, and provided with a light-weight and compact muffler (2). The engine is arranged with a particularly high crankcase compression created in that at least one filling (3, 4, 5, 6) is placed into the compression area (7) under the engine piston (8) in form of a filled balance (3) and/or a piston filling (4) and/or a piston washer (5) and/or a stationary filling (6), at the same time as the engine is provided with an especially strong throttling created in the engine's exhaust side, i.e. in its exhaust port (9) and/or in a possible exhaust duct (10) and/or in the muffler (2).

Abstract: An exhaust valve holder including accommodations for additional sealing and resistance to movement. This includes a groove wide enough for two sealing o-rings, a groove or slot which does not run the circumference of the holder and binds against a tab of a holder plate to resist rotational movement and a one piece design.

Abstract: Expansion chambers for two-cycle engines include a moveable closure piston which selectively increases the flow cross-sectional area geometrically upon increasing back pressure. The improved expansion chamber thus results in better regulation of the back pressure in the two-cycle engine. Several expansion chamber embodiments are disclosed.

Abstract: An exhaust arrangement for an internal combustion engine wherein the timing of the cylinder events is such that the exhaust port of one cylinder opens before the exhaust port of another cylinder closes so as to improve scavenging and performance. In preferred embodiments, the engine is of a 2-cycle type and the exhaust port of the one cylinder also opens before the scavenge port of the other cylinder closes. The principle is also depicted in conjunction with a four cylinder engine.

Abstract: A multiple cylinder internal combustion cylinder block having a cast exhaust manifold means integrally cast with the block is disclosed. The manifold means includes manifold port portions that communicate with the cylinder bores, and an expansion slot is provided in the manifold port portions adjacent the cylindrical bores to relieve stress that tends to distort the cylindrical bores of the block.

Abstract: A five cylinder two cycle outboard motor includes exhaust tuning of the five in-line cylinders. Exhaust tuning of five in-line cylinders provides increased horsepower for the five cylinder two cycle outboard motor. The five cylinder outboard motor which produces 150 horsepower achieves an ideal horsepower to number of cylinders and provides the proper horsepower size/weight size outboard motor for bass fishing and water skiing boats.

Abstract: An improved internal combustion engine, particularly of the compression ignition, two cycle, aircraft type employing sleeve valves and a modular cylinder and removable cylinder head and retainer. The engine is turbocharged with the turbocharger separated into the compressor on one side of a V shaped cylinder array and the drive turbine on the opposite side. The exhaust is discharged through the center of the power output shaft making this engine particularly suited for pusher aircraft applications.

Abstract: A two-stroke engine having at least one cylinder in which a piston is movably accommodated, with a crank case communicating with one end of the at least one cylinder. Air is admitted to the crank case and at least one pipe admits unmixed air from the crank case to a cylinder transfer port. The fuel is pneumatically injected into the cylinder by way of a pneumatic injector and a pipe connected to the crank case by a valve and forming a volume of pressurized air connected to the pneumatic injector supplies the pneumatic injector with pressurized air for atomizing the fuel. An exhaust pipe is connected to the at least one cylinder by an exhaust port located in a position offset in a direction of travel of the piston with respect to the cylindrical transfer port of the cylinder.

Abstract: The invention is directed to an arrangement for heating the intake air of the carburetor of the engine of a handheld portable tool such as a chain saw. The fresh air entering the air intake line is quickly and adequately heated and directed to the carburetor as intake air without the danger of this intake air becoming entrained with dirt particles. In the arrangement according to the invention, the handheld portable tool can be operated at low temperatures without disturbances in the carburetor system such as freezing of the throttle flap or the main nozzle. The air intake line is lead through the muffler which is configured as a collection chamber for the exhaust gas. The heat of the hot exhaust gases passing through the muffler is transferred to the fresh air entering and passing through the intake line.

Abstract: The idle exhaust pressure relief system in an outboard motor is utilized to simultaneously heat the engine crankcase or other parts of the fuel supply system to prevent the puddling of fuel typically occurring at lower engine temperatures. Because the idle exhaust pressure relief system is inherently operable to conduct hot exhaust gases out of the exhaust manifold only at idle or low speed operation, heat is supplied to the crankcase only at temperatures when fuel puddling typically occurs.

Abstract: A two-cycle engine includes a cylinder block having at least one pair of first and second cylinders, the first and second cylinders having a pair of first and second exhaust ports, respectively. A pair of first and second pistons are received respectively in the first and second cylinders for reciprocal movement therealong, each of the exhaust ports being selectively closed and opened by a respective one of the pistons during the movement thereof along a respective one of the cylinders. The first and second pistons are operatively connected to a crankshaft in such a manner that the first and second pistons are reciprocable 180.degree. out of phase along the respective cylinders. A final portion of the duration of opening of one of the exhaust ports overlaps an initial portion of the duration of opening of the other. An exhaust passage has a communicating portion communicating the first and second exhaust ports with each other adjacent thereto.

Abstract: Several embodiments of water cooled motorcycles incorporating an improved compact arrangement wherein the components do not interfere with each other or the rider's stance. In each embodiment the engine cooling system includes a heat exchanger that is positioned on one side of the frame adjacent the down tube. An exhaust system is incorporated that includes an expansion chamber that is disposed on the opposite side of the down tube and which is connected to the engine by a U-shaped section of sufficient length so as to provide the desired exhaust performance. In some embodiments the cooling capacity is increased by employing multiple radiator sections. In each embodiment the side-to-side balance of the motorcycle is maintained by the positioning and sizing of the components.

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: This invention comprehends a two-cycle internal combustion engine using compression relief to provide a dual compression ratio. Compression relief ports above the exhaust ports of two cylinders firing 180 degrees out of phase connected by a relief passage. The passage is vented at its midpoint. At higher engine speeds exhaust flow, from the cylinder in its power stroke, through the relief passage, blocks the flow from the cylinder in its compression stroke.

Abstract: In a two-stroke, water-cooled internal combustion engine the improvement is disclosed which permits to have a removable cylinder liner type of engine in spite of the intricate constructional arrangement of such engines having transfer ports and exhaust ports. The improvement consists in that the transfer and exhaust ports are formed through the liners and flanged fittings are provided between the liner transfer ports and the transfer ducts so as to ensure complete tightness. Differential-firmness gaskets are provided where appropriate and the engine is then assembled by stay bolts as usual. The construction suggested by the invention not only solves the tightness problem satisfactorily, but minimizes the stresses on the liners, especially the bending stresses.

Abstract: A two-stroke internal combustion engine having at least three cylinders includes an exhaust means with an exhaust cavity, an exhaust port at each cylinder and an exhaust port extension forming a chamber between the exhaust cavity and the exhaust port. Within the exhaust cavity exhaust pulse transmission means connect the port extension of an exhausting cylinder and the port extension of a charging cylinder with a pulse transmission path of a proper length to cause the exhaust pulse from an exhausting cylinder to arrive at the exhaust port of a charging cylinder prior to the complete closing of the exhaust port of the charging cylinder thereby forcing the air fuel mixture which escaped from the exhaust port of the charging cylinder and which is within the chamber thereof back into the charging cylinder prior to the closing of the exhaust port of the charging cylinder.

Abstract: A sixty degree, V-6 engine for an outboard motor includes loop scavenging and charging with a pair of oppositely located input passageways with differently angles sidewalls and which provide progressive, smooth constriction to the charging port to establish a highly effective velocity pattern across the top of a flat piston. Cast "Blister" cylinder liners with integral ports are integrally cast into an aluminum block. The block is cast with a single manifold between the two cylinder blanks. A milling cutter is located within the manifold to open the exhaust passageways. A T-shaped manifold is secured to close the manifold and define a pair of separate exhaust passageways. The cylinders are rotated to align the upper and lower inlet ports and particularly to locate the exhaust port projecting downwardly into a center manifold. Adjacent piston rods are mounted upon a common crankshaft pin.

Abstract: Disclosed is 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. The vaporization of the fresh combustible mixture is prometed in the first passage and, in addition, the fresh combustible mixture flows into the combustion chamber at a low speed. As a result of this, an active thermoatmosphere combustion is caused in the combustion chamber.

Abstract: A diesel engine cylinder head is provided with air gap inserts for insulating the combustion and exhaust gas exposed surfaces from the coolant jacket exposed walls so as to limit heat transfer to the engine coolant. Various insert elements are disclosed which may be used independently or in combination. Installation of a prefabricated multiple port exhaust insert which permits improved efficiency of gas flow is provided for by utilizing a two-piece construction for the main housing of the cylinder head.

Abstract: A power control valve attachment is provided for assembly to a pre-existing exhaust system of a two cycle motorcycle type engine for effecting a back pressuring of the engine cylinder chambers during operation of the engine and includes an assembly of pressure plate and spring biasing means and means for mounting the assembly in the exhaust system duct at a minimum cross sectional area thereof for axial deflective movement under the pressure of the exhaust gases.