Abstract: A control arrangement for a planing-type boat having an engine powering a water propulsion device is disclosed. The engine has at least one combustion chamber, an exhaust port leading from the combustion chamber, and an exhaust timing valve cooperable with the exhaust port. The exhaust timing valve is moveable between a first retracted position and a second extended position, where in the second position a flow of exhaust through the exhaust port has a shorter duration than when the valve is in the first position. A drive unit is associated with the exhaust timing valve. The control is arranged to move the exhaust timing valve with the drive unit from the second position towards the first position at a predetermined high engine speed. The control is arranged to prevent the rapid movement of said exhaust timing valve between its first and second positions when the engine speed fluctuates about the predetermined engine speed.

Abstract: A number of embodiments of two cycle crankcase compression internal combustion engines having at least two cylinders in a common bank in side-by-side relationship. Each embodiment incorporates a main Schnurle type scavenging system that includes a pair of main scavenge passages on opposite sides of the exhaust passage that terminate in main scavenge ports that are disposed in proximity to and on opposite sides of the exhaust port. A transversely extending supplemental scavenge passage is provided for delivering a charge to the combustion chamber to somewhat restrict the scavenging flow so as to prevent fuel from passing out of the exhaust port. Fuel is injected into proximity with this supplemental scavenge passage. This facilitates stratification of the fuel charge. The ports are rotated from normal around the cylinder bore axis in many embodiments to provide a more compact construction.

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: A number of embodiments of two cycle crankcase compression internal combustion engines having at least two cylinders in a common bank in side-by-side relationship. Each embodiment incorporates a main Schnurle type scavenging system that includes a pair of main scavenge passages on opposite sides of the exhaust passage that terminate in main scavenge ports that are disposed in proximity to and on opposite sides of the exhaust port. A transversely extending supplemental scavenge passage is provided for delivering a charge to the combustion chamber to somewhat restrict the scavenging flow so as to prevent fuel from passing out of the exhaust port. Fuel is injected into proximity with this supplemental scavenge passage. This facilitates stratification of the fuel charge. The ports are rotated from normal around the cylinder bore axis in many embodiments to provide a more compact construction.

Abstract: A two-cycle internal combustion engine includes a control valve disposed within a communicating passage between the combustion chamber and a chamber portion adjacent to the combustion chamber. The control valve is for controlling the opening and closing of the communicating passage. Blowby of an air-fuel mixture supplied to the combustion chamber can be prevented to reduce fuel consumption and increase the exhaust gas purifying performance. A communicating passage portion between the control valve and the fuel supply opening is configured to spray fuel from the control valve to a part or all of a wall surface of the communicating passage portion and the wall surface of the communicating passage portion is shaped to guide the fuel into the combustion chamber.

Abstract: A deflector comprising a U-shaped embossed part is provided on the top surface of the loop scavenging type two-cycle engine in such a direction that the opening of the U-shaped boss is on the side of the exhaust port of the cylinder, and a combustion chamber is shaped such that the U-shaped deflector of the piston is fitted therein and is placed in the cylinder head opposite the said top surface of the piston. When the piston rises and the deflector is fitted inside the combustion chamber of the cylinder head, there is formed a squish zone between the outside area of the deflector at the top surface of the piston and the cylinder head for pressing the air-fuel mixture into the combustion chamber, to thereby decrease the emission of unburned gas containing harmful hydrocarbons and the improve the combustion efficiency for higher output.

Abstract: Disclosed is a device for controlling the flow of intake and exhaust gases in an internal combustion engine, which comprises a cylinder head with a plurality of cylinders each forming combustion chamber for burning air/fuel mixture to produce a mechanical energy, the combustion chamber having an intake valve for receiving an air/fuel mixture and an exhaust valve for exhausting burnt gases, a blocking means for isolating the side of the intake valve from the side of the exhaust valve so as to prevent a fresh air/fuel mixture and the burnt gases from interfering with each other in the overlap interval between the final stage of the exhaust stroke and the beginning stage of the intake stroke during which the intake and exhaust valves simultaneously maintain the opening state, and a cam shaft for driving the intake and exhaust valves and the blocking means.

Abstract: An exhaust port is formed in the wall of a cylinder of a 2-cycle engine. At least one of the portions of the cylinder wall which define two vertically opposing edges of the exhaust port is projected at the circumferentially mid portion towards the opposing edge so as to provide a piston guide surface which conforms with the inner peripheral surface of the cylinder and which extends in such a manner as to reduce the axial height of the exhaust port. The piston guide surface serves to suppress vibration and noise caused when an upwardly moving piston falls into the exhaust port.

Abstract: A combustion chamber for an internal combustion engine is provided which includes a cylinder head body having at least one generally dome-shaped combustion chamber defined by a lower surface of the body and having an intake side and an exhaust side, and a spark plug bore disposed in the combustion chamber so that when a spark plug is engaged in the bore, the dome-shaped portion is provided with an upper surface configured to shelter the electrode from direct impingement of a fresh charge introduced into the combustion chamber through the intake side.

Abstract: A number of embodiments of scavenging port configurations for two-cycle internal combustion engines wherein the a scavenge port is formed adjacent the exhaust port and is masked by a cylinder liner so as to avoid the escape of scavenging gases to the exhaust port, particularly at the end of the scavenging cycle.

Abstract: In known two-stroke internal combustion engines with piston-controlled intake passages for the fresh charge and one or more exhaust passages for the exhaust gases, the actual direction of flow will deviate from the theoretical flow direction defined by the passage walls because of the influence exerted by the piston edge. The scavenge flow is deflected in the direction of the exhaust passage and the cylinder head, which will cause increased losses of fresh charge. This will considerably lower scavenge efficiency, and thus lead to a marked deterioration of engine performance, fuel consumption and exhaust emission. In the invention these disadvantages are avoided by aligning the flow guide vanes such that they form an angle, preferably of 90.degree., thus acting as a flow director.

Abstract: Disclosed is a two-cycle internal combustion engine including a protruding edge portion formed in a section of a lower side surface of an intake port which is adjacent to a pre-compression chamber of a cylinder. This protruding edge portion serves to deflect air-fuel mixture introduced into the pre-compression chamber through the intake port so as to direct it to a bearing portion provided between a piston and a connecting rod. Further, a cut-in groove is formed in the protruding edge section and is adapted to allow any liquid remaining in the intake port to flow into the pre-comparison chamber.

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: In a two-stroke internal combustion piston engine, a piston is reciprocally movable within an axially elongated cylinder. The piston has a bottom dead center position and in the region of this position, the cylinder has an exhaust opening and a number of pairs of scavenging openings. An axially extending plane within the cylinder divides the exhaust opening in half and in each pair the scavenging openings are arranged symmetrically on opposite sides of the axially extending plane. Each pair of scavenging openings is located at a different distance from the exhaust opening. The projection of the side surfaces of the pairs of scavenging openings extending in the axial direction of the cylinder each form a different angle at the point of intersection of the projections and the point of intersection is directed away from the exhaust opening.

Abstract: In a two cycle internal combustion engine having a cylinder, a piston, and an exhaust port, the improvement comprising tapering the edge of the exhaust port farthest into the cylinder where it intersects the cylinder wall as an isosceles triangle.

Abstract: A two-stroke cycle gasoline engine including at least one two-stroke cycle uniflow scavenging power cylinder-piston assembly which has a scavenging port configuration which consists of first, second, and third scavenging port configurations which are successively uncovered by the power piston as it moves from its top dead center to its bottom dead center, wherein the first scavenging port configuration has a substantially smaller opening area than the second or the third scavenging port configuration, and the first and the second scavenging port configurations give substantially stronger swirl to fuel-air mixture discharged therefrom than the third scavenging port configuration, which gives substantially no swirl to fuel-air mixture discharged therefrom, and the first and second port configurations are closed when the engine is operating at relatively low load above idling and below a predetermined delivery ratio, such as 0.4.

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: 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 a scavenging structure which gives zero or a relatively weak swirl to the scavenging mixture ejected into the power cylinder so as to effect stratified scavenging of exhaust gases when the engine is operating at relatively low load and which gives a relatively strong swirl to the scavenging mixture ejected into the power cylinder so as to cause high turbulence in the mixture when the engine is operating at relatively high load.

Abstract: An improved two-cycle Diesel internal combustion engine is provided, whereby the intake and exhaust port passages are modified to provide greater circulation of the combustible fluids and air during the intake and exhaust cycles of the Diesel engine, respectively. The intake passages are so located in each piston and each cylinder to provide communication thereinbetween during the intake cycle with the piston at the bottom of its stroke which effects the exhaust cycle simultaneously substantially similar to a normal two-cycle operation. The intake passages in each cylinder communicate with intake passages in each piston which are connected to an intake flume port located epicentrically in the upper portions of each piston. The movement of the combustible fluids and the evacuation air is directed from the intake flume port and deflected off a conical protrusion in the upper surface of the cylinder, in order to promote circulation of the combustible fluids and the evacuation air, respectively.

Abstract: Disclosed herein is a two-cycle, internal combustion engine including a piston mounted for reciprocative movement inside a cylinder and having a top and an inlet face portion which periodically covers and uncovers an intake port during reciprocative movement of the piston, a circumferentially extending recess in the piston at the juncture between the top and inlet face portion thereof and having an inner wall which extends in front of a limited portion of the intake port located farthest away from the outlet port such that, as the piston inlet face starts to uncover the intake port, an initial flow of fresh charge flows through only the limited portion of the intake port and is deflected by the recess inner wall towards the cylinder head and along the cylinder intake wall in a direction generally parallel to the longitudinal axis of the cylinder, and a deflector carried on the top of the piston and spaced inwardly from the piston recess for deflecting additional streams of fresh charge flowing through the int