A piston internal combustion engine with generator has two cylinders and cylinder heads and pistons with connecting rods and two crankshafts which are connected by gears with a ratio of 1:−1 (with opposite direction of rotation). The first crankshaft with the gear is mounted parallel to the second crankshaft with the second gear in one engine case such, that the gears engage. The first crankshaft is coupled to the first generator rotor and the second crankshaft is coupled to the second generator rotor or the flywheel. The moment of inertia of the first crankshaft assembly with the first gear and the first generator rotor is equal to the moment of inertia of the second crankshaft assembly with the second gear and the second generator rotor or flywheel. The cylinders with the pistons and are positioned perpendicularly to the plane of symmetry between the crankshafts, with the axes of the pair of cylinders lying in a plane with the both pistons being at the top dead center simultaneously.

An engine is provided with: an engine body; and a top cover that covers the engine body, wherein at least a pair of engaging claws are provided to lateral walls, on both sides, of the top cover so as to extend downward, and a pair of engaging holes with which the engaging claws engage are provided to the engine body side. Each of the engaging claws is provided with a plate section that is provided so as to extend downward, and a bulging section that is provided to the leading end of the plate section and that bulges inward from the plate section, and the bulging section engages with the bottom surface of an inner wall section of the corresponding engaging hole.

An engine is provided with: an engine body; and a top cover that covers the engine body, wherein at least a pair of engaging claws are provided to lateral walls, on both sides, of the top cover so as to extend downward, and a pair of engaging holes with which the engaging claws engage are provided to the engine body side. Each of the engaging claws is provided with a plate section that is provided so as to extend downward, and a bulging section that is provided to the leading end of the plate section and that bulges inward from the plate section, and the bulging section engages with the bottom surface of an inner wall section of the corresponding engaging hole.

An arrangement of exchangers for marinization of a marine engine, including an engine block with in-line cylinders or cylinders in a V, cooled by a cooling fluid, at least one turbocompressor with a hot chamber connected to an outlet and a cold chamber connected to the cylinders of the engine block, a reverser including a housing and containing oil, wherein the arrangement includes: a radiator hose for supplying cooling water, a turbocompressor exchanger, an engine exchanger, a reverser exchanger, a radiator hose for discharging cooling water toward an outlet of combustion gases, downstream from the hot chamber of the at least one turbocompressor,
with these three exchangers being placed in this order and inserted in the circulation direction of the water between the radiator hose for supplying the cooling water and the radiator hose for discharging this same cooling water.

An arrangement of exchangers for marinization of a marine engine, including an engine block with in-line cylinders or cylinders in a V, cooled by a cooling fluid, at least one turbocompressor with a hot chamber connected to an outlet and a cold chamber connected to the cylinders of the engine block, a reverser including a housing and containing oil, wherein the arrangement includes: a radiator hose for supplying cooling water, a turbocompressor exchanger, an engine exchanger, a reverser exchanger, a radiator hose for discharging cooling water toward an outlet of combustion gases, downstream from the hot chamber of the at least one turbocompressor,
with these three exchangers being placed in this order and inserted in the circulation direction of the water between the radiator hose for supplying the cooling water and the radiator hose for discharging this same cooling water.

Internal combustion engines having a split crankshaft are disclosed. The engines may also have non-circular, preferably rectangular, cross-section pistons and cylinders. The pistons may include a skirt with a field of pockets that provide a ringless, non-lubricated, seal equivalent. The pistons also may have a domed piston head with depressions thereon to facilitate the movement of air/charge in the cylinder. The engines also may use multi-stage poppet valves in lieu of conventional poppet valves. The engines may use the pumping motion of the engine piston to supercharge the cylinder with air/charge. The engines also may operate in an inverted orientation in which the piston is closer to the local gravitationally dominant terrestrial body's center of gravity at top dead center position than at bottom dead center position.

Internal combustion engines having a split crankshaft are disclosed. The engines may also have non-circular, preferably rectangular, cross-section pistons and cylinders. The pistons may include a skirt with a field of pockets that provide a ringless, non-lubricated, seal equivalent. The pistons also may have a domed piston head with depressions thereon to facilitate the movement of air/charge in the cylinder. The engines also may use multi-stage poppet valves in lieu of conventional poppet valves. The engines may use the pumping motion of the engine piston to supercharge the cylinder with air/charge. The engines also may operate in an inverted orientation in which the piston is closer to the local gravitationally dominant terrestrial body's center of gravity at top dead center position than at bottom dead center position.

An outboard includes a plurality of first branched pipes connected to a plurality of first exhaust ports and a plurality of second branched pipes connected to a plurality of second exhaust ports, respectively, wherein the plurality of first branched pipes are connected to a first collecting pipe and the plurality of second branched pipes are connected to a second collecting pipe. A connector connects the first collecting pipe and the second collecting pipe. The plurality of first branched pipes extend in a direction away from the connector in a plan view, and each includes a first exhaust pathway located farther away from the connector than the first collecting pipe is in the plan view. The plurality of second branched pipes extend in a direction away from the connector in a plan view, and each includes a second exhaust pathway located farther away from the connector than the second collecting pipe is in the plan view.

An outboard includes a plurality of first branched pipes connected to a plurality of first exhaust ports and a plurality of second branched pipes connected to a plurality of second exhaust ports, respectively, wherein the plurality of first branched pipes are connected to a first collecting pipe and the plurality of second branched pipes are connected to a second collecting pipe. A connector connects the first collecting pipe and the second collecting pipe. The plurality of first branched pipes extend in a direction away from the connector in a plan view, and each includes a first exhaust pathway located farther away from the connector than the first collecting pipe is in the plan view. The plurality of second branched pipes extend in a direction away from the connector in a plan view, and each includes a second exhaust pathway located farther away from the connector than the second collecting pipe is in the plan view.

Methods and systems are provided for diagnosing an active exhaust valve in an exhaust system based on thermal data. In one example, a method may include indicating degradation of a first active exhaust valve positioned in a first exhaust pipe of a first engine bank based on a difference between a first temperature of exhaust downstream of the first active exhaust valve and a second temperature of exhaust downstream of a second active exhaust valve positioned in a second exhaust pipe of a second engine bank. Degradation of the valve may be confirmed based on thermal image data acquired at outlets of the first and second exhaust pipes.