Abstract: A marine drive system includes an engine, a fuel system that provides at least two different fuels to the engine, and a fuel selection means for selecting a fuel type. A control unit accesses a set of fuel-specific operating parameters based on the selected fuel type and controls the engine based on the set of fuel-specific operating parameters.

Abstract: An outboard motor is provided with an engine having a screw compressor which provides a pressurized charge for the combustion chambers of the engine. The screw compression has first and second screw rotors arranged to rotate about vertical axes which are parallel to the axes of a crankshaft of the engine. A bypass valve regulates the flow of air through a bypass conduit extending from an outlet passage of the screw compressor to the inlet passage of the screw compressor. A charge air cooler is used in a preferred embodiment and the bypass conduit then extends between the cold side plenum of the charge air cooler and the inlet of the compressor. The charge air cooler improves the operating efficiency of the engine and avoids overheating the air as it passes through the supercharger after flowing through the bypass conduit.

Abstract: An outboard motor is provided with an engine having a screw compressor which provides a pressurized charge for the combustion chambers of the engine. The screw compression has first and second screw rotors arranged to rotate about vertical axes which are parallel to the axes of a crankshaft of the engine. A bypass valve regulates the flow of air through a bypass conduit extending from an outlet passage of the screw compressor to the inlet passage of the screw compressor. A charge air cooler is used in a preferred embodiment and the bypass conduit then extends between the cold side plenum of the charge air cooler and the inlet of the compressor. The bypass valve is controlled by an engine control module in order to improve power output from the engine at low engine speeds while avoiding any violation of existing limits on the power of the engine at higher engine speeds.

Abstract: A marine engine is made with a head portion that includes an exhaust manifold that is formed as an integral part of the head portion during a lost foam casting procedure. The head portion comprises a plurality of combustion chambers in which each combustion chamber has at least one exhaust throat that connects the combustion chamber in fluid communication with at least one exhaust port. All of the exhaust ports connect associated combustion chambers in fluid communication with an exhaust manifold that is formed integrally within the head portion during the initial lost foam casting process. An exhaust outlet opening from the exhaust manifold is positioned above at least one exhaust port of at least one combustion chamber to form a water trap or stand pipe that inhibits water ingestion under certain adverse conditions. Water passages and oil passages are formed integrally within the head portion during the lost foam casting process.

Abstract: A single cylinder, internal combustion engine with a dry sump lubrication system. The engine includes an engine housing in which the overhead camshaft and crankshaft are rotatably supported, and the housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. Dry sump lubrication is obtained by an external oil reservoir connected to a pump which supplies pressurized oil to the bearing journals of the camshaft. A portion of the oil at the camshaft bearing journals flows through passages provided within the cylinder to lubricate the bearing journals of the crankshaft.

Abstract: A single cylinder, internal combustion engine with a dry sump lubrication system. The engine includes an engine housing in which the overhead camshaft and crankshaft are rotatably supported, and the housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. Dry sump lubrication is obtained by an external oil reservoir connected to a pump which supplies pressurized oil to the bearing journals of the camshaft. A portion of the oil at the camshaft bearing journals flows through passages provided within the cylinder to lubricate the bearing journals of the crankshaft.

Abstract: A single cylinder, internal combustion engine with a dry sump lubrication system. The engine includes an engine housing in which the overhead camshaft and crankshaft are rotatably supported, and the housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. Dry sump lubrication is obtained by an external oil reservoir connected to a pump which supplies pressurized oil to the bearing journals of the camshaft. A portion of the oil at the camshaft bearing journals flows through passages provided within the cylinder to lubricate the bearing journals of the crankshaft.

Abstract: A single cylinder, internal combustion engine with an engine housing in which the overhead camshaft and crankshaft are rotatably supported. The housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. The inventive engine further provides for the mounting of flywheels within the crankcase cavity in conjunction with an external, lightweight fan for engine housing cooling, as well as employs a cast in valve seat for the overhead valve assemblies.

Abstract: A single cylinder, internal combustion engine with a dry sump lubrication system. The engine includes an engine housing in which the overhead camshaft and crankshaft are rotatably supported, and the housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. Dry sump lubrication is obtained by an external oil reservoir connected to a pump which supplies pressurized oil to the bearing journals of the camshaft. A portion of the oil at the camshaft bearing journals flows through passages provided within the cylinder to lubricate the bearing journals of the crankshaft.

Abstract: An overhead camshaft internal combustion engine having a plastic camshaft which extends through an opening on the cylinder head, the plastic camshaft having a seal ring disposed around the outer surface of the molded plastic camshaft to provide an interface surface for contacting a seal assembly disposed between the engine casing and the molded plastic camshaft. The seal assembly and the seal ring provide a fluid tight seal to prevent leakage of fluid through the cylinder head opening. The seal ring provides a smooth contact surface for the molded plastic camshaft to prevent wear and damage to the seal assembly from the abrasive surface of the molded plastic camshaft. The seal ring also provides a heat sink for dissipating the frictional heat generated by the rotation of the camshaft. In another form, the plastic camshaft includes a powder metal surface formed thereon. The powder metal surface provides the same benefits as the seal ring, namely protection from wear and dissipation of heat.

Abstract: An overhead cam internal combustion engine having a slanted head design which permits the camshaft assembly comprising a camshaft, rocker arms and valve assemblies to be pre-assembled to the head and valve lash to be set off of the main engine assembly line. The slanted head design allows the chain sprocket and timing chain for driving the camshaft to be installed thereon after the head has been assembled to the engine block, accommodating the easy installation of the timing chain. L-shaped rocker arms, mounted on a single shaft, follow a single lobe overhead camshaft. Each rocker arm actuates a valve located on the side of the camshaft opposite that which it follows.

Abstract: A single cylinder, internal combustion engine with a dry sump lubrication system. The engine includes an engine housing in which the overhead camshaft and crankshaft are rotatably supported, and the housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. Dry sump lubrication is obtained by an external oil reservoir connected to a pump which supplies pressurized oil to the bearing journals of the camshaft. A portion of the oil at the camshaft bearing journals flows through passages provided within the cylinder to lubricate the bearing journals of the crankshaft.