Abstract: A plurality of cylinders are defined in a single cylinder block, and a single cylinder head common to the cylinders is mounted on the cylinder block. Exhaust passages are provided in the cylinder head at a location corresponding to an inner side and central portion of a V-shape formed by the cylinders, the exhaust passages communicating with the cylinders, respectively. Intake passages are provided in the cylinder head at a location corresponding to opposite outside positions of the V-shape, the intake passages communicating with the cylinders, respectively. The intake passages open into a side of the cylinder head on opposite sides of the V-shape, and fuel injection nozzles provided in the intake passages, respectively. The exhaust passage extend parallel to a crankshaft within the cylinder head and open into the corresponding side of the cylinder head. A water jacket is defined around the exhaust passages to surround the exhaust passages.

Abstract: An outboard engine structure is provided including an engine mounted in an upper portion of the structure, wherein an exhaust gas from the engine is passed through an exhaust passage located vertically within an engine body case, into a lower portion of the case and discharged into water. A catalytic converter is positioned adjacent an oil pan the said engine. The oil pan is mounted in a suspended manner in an upper area within the engine body case and the catalytic concerted is incorporated in the middle of the exhaust passage. The catalytic converter is fixed to and supported on the oil pan. Thus, it is easy to place the catalytic converter in the engine body case.

Abstract: A four-cycle engine including a magnetic detection sensor mounted on a non-magnetic cam shaft pulley which is rotated in operative association with a crank pulley for detecting a plurality of detecting portions formed on the magnetic detection member by coils mounted in the cylinder head. The magnetic detection member is integrally formed with the plurality of detection portions for different uses such that distances from the center of rotation of the cam shaft pulley to the plurality of detection portions are different, and wherein the coils are separately mounted in correspondence to the detection portions. Thus, it is possible not only to take out timing signals for different uses from a single cam shaft pulley, but also to eliminate interference between the discrete coils.

Abstract: A V-type multi-cylinder 4-cycle engine E accommodated in an engine room in an outboard motor includes a pair of left and right banks. A surge tank is disposed in a space defined between both the banks and connected to two left and right combustion chambers through intake ports. A throttle body is connected to a lower portion of the surge tank and also to an intake silencer mounted in a left space of the engine room through an elbow. A subsidiary tank for supplying a fuel to an injector is disposed symmetrically with the intake silencer in a right space of the engine room. The employment of the above-described layout makes it possible to make an intake device move compact in the 4-cycle engine.

Abstract: Disclosed is a method of adding silicon to aluminum. The method is characterized in that silicon particles having a diameter ranging between 2 mm and 50 mm are added to a molten aluminum together with a flux represented by the general formula XaMFb, where "X" represents an element included in the third or fourth period of the Periodic Table, "M" is a III or IV group element of the Periodic Table, and "F" is fluorine. A part of the flux may be added in the form of coating on the surface of the silicon particle.