Intake ports include a second port configured such that a flow rate of flowing gas is adjusted via a swirl control valve. When a surge tank is viewed in a cylinder axis direction, first and second branched passages are connected with a space being interposed therebetween in a cylinder array direction, and are connected to the surge tank on extension lines, each of which extends from an upstream end portion of an independent passage connected to the second port to an opposite side of each cylinder.

Intake ports include a second port configured such that a flow rate of flowing gas is adjusted via a swirl control valve. When a surge tank is viewed in a cylinder axis direction, first and second branched passages are connected with a space being interposed therebetween in a cylinder array direction, and are connected to the surge tank on extension lines, each of which extends from an upstream end portion of an independent passage connected to the second port to an opposite side of each cylinder.

An exhaust-gas discharge port to discharge a main flow of exhaust gas passing through an exhaust-gas purifying device is provided at a position which is offset, on one side, from a center axis of the purifying-device body, and an EGR-gas takeout port is provided at a position which is offset, on an opposite side to the exhaust-gas discharge port, from the center axis of the purifying-device body.

An exhaust-gas discharge port to discharge a main flow of exhaust gas passing through an exhaust-gas purifying device is provided at a position which is offset, on one side, from a center axis of the purifying-device body, and an EGR-gas takeout port is provided at a position which is offset, on an opposite side to the exhaust-gas discharge port, from the center axis of the purifying-device body.

The present invention is directed to a dual engine-compressor system having a crankcase enclosing a crankshaft and having engine cylinder housings and compressor cylinder housings linearly disposed on opposite sides of the crankcase. Combustion pistons are reciprocatingly disposed in the engine cylinder housings and defines alternating combustion chambers on opposite sides of the pistons. Compressor pistons are reciprocatingly disposed in the compressor housings and define alternating low and high pressure compressor chambers on opposite sides of the compressor pistons. The compressor pistons underdo a 4-cycle process to drawn in, re-distribute, and then compress fluid. The compressor cylinder and piston has a series of one-way intakes and reed valves to selectively draw or push fluid in response to movement of the compressor piston.

The present invention is directed to a dual engine-compressor system having a crankcase enclosing a crankshaft and having engine cylinder housings and compressor cylinder housings linearly disposed on opposite sides of the crankcase. Combustion pistons are reciprocatingly disposed in the engine cylinder housings and defines alternating combustion chambers on opposite sides of the pistons. Compressor pistons are reciprocatingly disposed in the compressor housings and define alternating low and high pressure compressor chambers on opposite sides of the compressor pistons. The compressor pistons underdo a 4-cycle process to drawn in, re-distribute, and then compress fluid. The compressor cylinder and piston has a series of one-way intakes and reed valves to selectively draw or push fluid in response to movement of the compressor piston.

Various methods and systems are provided for reducing cylinder-to-cylinder variation in exhaust gas recirculation. In one embodiment, a system comprises a first cylinder group of an engine having a first number of cylinders, a second cylinder group of the engine having a second number of cylinders that is not an integer multiple of the first number of cylinders, and an exhaust system coupled to the first cylinder group and the second cylinder group. In at least one mode of operation, the exhaust system has exhaust ports of the first cylinder group fluidly coupled to an intake of the engine and exhaust ports of the second cylinder group fluidly decoupled from the intake.

Various methods and systems are provided for reducing cylinder-to-cylinder variation in exhaust gas recirculation. In one embodiment, a system comprises a first cylinder group of an engine having a first number of cylinders, a second cylinder group of the engine having a second number of cylinders that is not an integer multiple of the first number of cylinders, and an exhaust system coupled to the first cylinder group and the second cylinder group. In at least one mode of operation, the exhaust system has exhaust ports of the first cylinder group fluidly coupled to an intake of the engine and exhaust ports of the second cylinder group fluidly decoupled from the intake.

Embodiments of outboard motors and related systems and components thereof, as well as arrangements of marine vessels implementing same, as well as related methods of operation, use, assembly, and manufacture, and related improvements, are disclosed herein. In at least some embodiments, the outboard motor includes a cowling system in which at least one divider portion separates an interior region into first and second portion, with the transmission and engine respectively being situated in the first and second portions, respectively. Additionally, in at least some embodiments, the outboard motor includes a water pump system in which a water pump is integrated with the transmission. Further, in at least some embodiments, the outboard motor includes a fuel vaporization suppression feature, or an oil tank feature that allows for desirable oil drainage from the engine of the outboard motor particularly when the outboard motor is in particular (e.g., storage) positions.

An intake device for an internal combustion engine, the intake device includes: a housing constituting an intake passage; a valve element including a valve portion arranged to open and close a part of the intake passage, and thereby to strengthen an intake air flow; and a receiving portion which is formed on a bottom wall of an aeration passage of the housing, and which is recessed in an arc shape along a movement trajectory of the valve portion, the valve portion including an outer side surface which confronts a bottom surface of the receiving portion, which has an arc shape, and which includes a seal portion that has a raised shape, and that extends along an edge portion on an upstream side of an intake direction.