Abstract: This oil case of an outboard motor is provided below an engine and stores lubricating oil of the engine. In this method for manufacturing the oil case, the oil case is manufactured so as to comprise: an oil chamber; an introduction path that guides upward cooling supply water drawn in from outside the outboard motor; a delivery path that guides downward cooling discharge water that has cooled the engine; a main exhaust path that guides exhaust gas of the engine downward; and a sub exhaust path that guides exhaust gas during low-speed rotation of the engine. The oil chamber, the introduction path, the delivery path, the main exhaust path and the sub exhaust path form an integral structure.

Abstract: A V8 engine, each bank of which is configured such that four crank pins connected to four piston pins via a connecting rod are positioned at 90° intervals when viewed from one end of a crankshaft. The four crank pins on the bank side are offset by 60° relative to the four crank pins on the bank side when viewed from the one end.

Abstract: An internal combustion engine is provided with: two intake pipe portions for guiding intake air to two banks; and a blow-by gas recirculation pathway for leading blow-by gas to the two intake pipe portions from a cylinder head or a crank case that includes the two banks. The blow-by gas recirculation pathway includes a distribution passage which is provided between the two intake pipe portions, and which distributes the blow-by gas and allows the same to flow to the two intake pipe portions.

Abstract: An outboard motor is provided with an upper separator disposed on the lower side of an oil case for storing a lubricating oil of an engine, and an extension case which is separably connected on the lower side of the upper separator. The upper separator has a central exhaust passage through which exhaust gas flows, and a cooling water flow part through which cooling water flows on the outside of the central exhaust passage, the central exhaust passage and the cooling water flow part forming an integrated structure. The exhaust gas and the cooling water are caused to mix in the extension case.

Abstract: A cooling structure for an outboard motor comprises an oil case which has an oil chamber for storing lubricant oil for an engine. Said cooling structure further comprises: a main exhaust gas passage which guides exhaust gas to a lower side; a cooling water outbound path which guides cooling supply water taken from outside the outboard motor to an upper side, and cools the periphery of the main exhaust gas passage in the oil case by means of the cooling supply water; a cooling water inbound path which guides cooling discharge water that has cooled the engine to the lower side and cools the oil chamber by means of said cooling discharge water; and a mixed fluid passage which, on a side below the oil case, cools the exhaust gas by mixing the exhaust gas and the cooling discharge water.

Abstract: Engine includes: crankcase housing crankshaft extending in vertical direction; cylinder block mounted on side of crankcase and formed with cylinder; cylinder head mounted on side of cylinder block and provided with air inlet port and air outlet port communicating with cylinder; cylinder head cover mounted on side of cylinder head and covering air inlet port and air outlet port; mount case including: supporting portion provided below crankcase and cylinder block and supporting crankcase and cylinder block; and extending portion extending from supporting portion below cylinder head and cylinder head cover; oil pan provided below mount case and storing lubricating oil; and communication tube communicating first space formed between cylinder head and cylinder head cover and second space formed between mount case and oil pan. Communication tube is provided between cylinder head cover and extending portion.

Abstract: A V-type multi-cylinder engine including a pair of banks, includes: an intake member forming an intake passage through which air is guided from outside; a pair of throttles each configured to regulate an amount of the air sucked into each of the pair of banks through the intake passage; and one single temperature sensor configured to detect a temperature of the air in the intake passage. The intake member includes a pair of openings downstream in a flowing direction of the air. Each the pair of throttles is connected to each of the pair of openings. The temperature sensor is disposed between the pair of openings.

Abstract: A V8 engine, each bank of which is configured such that four crank pins connected to four piston pins via a connecting rod are positioned at 90° intervals when viewed from one end of a crankshaft. The four crank pins on the bank side are offset by 60° relative to the four crank pins on the bank side when viewed from the one end.

Abstract: An outboard motor catalytic converter that can downsize an outboard motor by making a space, where catalysts are installed, small and can ensure efficient reaction of the catalysts. The outboard motor catalytic converter includes exhaust pipes that are connected to exhaust manifolds of an engine of the outboard motor. Catalysts are installed inside the exhaust pipes, and at least a portion of each of the exhaust pipes, which corresponds to a place where the catalysts are installed, is formed to have a double structure constituted of an inner pipe and an outer pipe.

Abstract: An internal combustion engine is provided with: two intake pipe portions for guiding intake air to two banks; and a blow-by gas recirculation pathway for leading blow-by gas to the two intake pipe portions from a cylinder head or a crank case that includes the two banks. The blow-by gas recirculation pathway includes a distribution passage which is provided between the two intake pipe portions, and which distributes the blow-by gas and allows the same to flow to the two intake pipe portions.

Abstract: A V-type multi-cylinder engine including a pair of banks, includes: an intake member forming an intake passage through which air is guided from outside; a pair of throttles each configured to regulate an amount of the air sucked into each of the pair of banks through the intake passage; and one single temperature sensor configured to detect a temperature of the air in the intake passage. The intake member includes a pair of openings downstream in a flowing direction of the air. Each the pair of throttles is connected to each of the pair of openings. The temperature sensor is disposed between the pair of openings.

Abstract: This outboard machine has: a V-type engine (engine) in which a plurality of cylinders are arranged in a V-shape when viewed in a plan view; and a cover that covers the engine. The engine has a plurality of intake ports that form pairs in a V-shape inside the plurality of cylinders in a plan view and a concave space is formed between the plurality of intake ports. The cover has therein an intake path that guides air to the intake port, and is also provided with, at a position that is adjacent to the intake path and enters the concave space, a silencer that attenuates the sound during intake.

Abstract: Engine includes: crankcase housing crankshaft extending in vertical direction; cylinder block mounted on side of crankcase and formed with cylinder; cylinder head mounted on side of cylinder block and provided with air inlet port and air outlet port communicating with cylinder; cylinder head cover mounted on side of cylinder head and covering air inlet port and air outlet port; mount case including: supporting portion provided below crankcase and cylinder block and supporting crankcase and cylinder block; and extending portion extending from supporting portion below cylinder head and cylinder head cover; oil pan provided below mount case and storing lubricating oil; and communication tube communicating first space formed between cylinder head and cylinder head cover and second space formed between mount case and oil pan. Communication tube is provided between cylinder head cover and extending portion.

Abstract: An exhaust pipe has an upstream-side exhaust pipe extending downward from an engine to house a catalyst for exhaust gas purification, and a downstream-side exhaust pipe located downstream of the upstream-side exhaust pipe, and extending upward from the catalyst and then bending downward. Under a configuration in which an exhaust pipe is disposed below an engine, with a simple configuration, a catalyst is hardly exposed to water.

Abstract: This outboard machine has: a V-type engine (engine) in which a plurality of cylinders are arranged in a V-shape when viewed in a plan view; and a cover that covers the engine. The engine has a plurality of intake ports that form pairs in a V-shape inside the plurality of cylinders in a plan view and a concave space is formed between the plurality of intake ports. The cover has therein an intake path that guides air to the intake port, and is also provided with, at a position that is adjacent to the intake path and enters the concave space, a silencer that attenuates the sound during intake.

Abstract: An outboard motor catalytic converter that can downsize an outboard motor by making a space, where catalysts are installed, small and can ensure efficient reaction of the catalysts. The outboard motor catalytic converter includes exhaust pipes that are connected to exhaust manifolds of an engine of the outboard motor. Catalysts are installed inside the exhaust pipes, and at least a portion of each of the exhaust pipes, which corresponds to a place where the catalysts are installed, is formed to have a double structure constituted of an inner pipe and an outer pipe.

Abstract: An outboard motor that controls combustion in an engine according to a purification rate by a catalyst and is capable of performing efficient engine combustion. The outboard motor includes a catalyst provided in an exhaust manifold of an engine and a second catalyst provided in an exhaust pipe, an air-fuel ratio sensor and an O2 sensor, which are located on an upstream side and a downstream side of the catalyst, respectively, and a controller for controlling combustion in the engine. The controller calculates an exhaust gas purification rate based on a value detected by the air-fuel ratio sensor or the O2 sensor and controls the combustion in the engine so as to make the exhaust gas purification rate appropriate.

Abstract: An outboard motor is provided with an upper separator disposed on the lower side of an oil case for storing a lubricating oil of an engine, and an extension case which is separably connected on the lower side of the upper separator. The upper separator has a central exhaust passage through which exhaust gas flows, and a cooling water flow part through which cooling water flows on the outside of the central exhaust passage, the central exhaust passage and the cooling water flow part forming an integrated structure. The exhaust gas and the cooling water are caused to mix in the extension case.

Abstract: This oil case of an outboard motor is provided below an engine and stores lubricating oil of the engine. In this method for manufacturing the oil case, the oil case is manufactured so as to comprise: an oil chamber; an introduction path that guides upward cooling supply water drawn in from outside the outboard motor; a delivery path that guides downward cooling discharge water that has cooled the engine; a main exhaust path that guides exhaust gas of the engine downward; and a sub exhaust path that guides exhaust gas during low-speed rotation of the engine. The oil chamber, the introduction path, the delivery path, the main exhaust path and the sub exhaust path form an integral structure.

Abstract: A cooling structure for an outboard motor comprises an oil case which has an oil chamber for storing lubricant oil for an engine. Said cooling structure further comprises: a main exhaust gas passage which guides exhaust gas to a lower side; a cooling water outbound path which guides cooling supply water taken from outside the outboard motor to an upper side, and cools the periphery of the main exhaust gas passage in the oil case by means of the cooling supply water; a cooling water inbound path which guides cooling discharge water that has cooled the engine to the lower side and cools the oil chamber by means of said cooling discharge water; and a mixed fluid passage which, on a side below the oil case, cools the exhaust gas by mixing the exhaust gas and the cooling discharge water.