A vehicle includes an engine unit, a radiator, a first passage, and a second passage which is provided below the cylinder head and to which lubricating liquid is supplied. The radiator is arranged in front of the engine unit. The first passage includes a first opening arranged in front of the radiator so as to face the radiator and is configured to guide first traveling wind from the first opening toward the radiator. The second passage includes a second opening arranged outside the first opening in the vehicle width while being partitioned from the first opening, and is configured to guide second traveling wind from the second opening toward the lower supplied member.

Disclosed is an oil passageway structure for an engine, which comprises: a body-side oil passage; a cover-side oil passage; an oil passage coupling section in which a first mating face formed around a peripheral edge of an endless transmission band cover-facing open end of the body-side oil passage is coupled to a second mating face formed around a peripheral edge of a body-side oil passage-facing open end of the cover-side oil passage; a groove formed in one of the first mating face and the second mating face; a cutout provided in the one mating face formed with the groove; and a sealing member attached to the groove, wherein the sealing member is formed with an outward protrusion protruding beyond an outer edge-side end of the cutout, and the cutout is formed inclinedly with respect to a cylinder axis as viewed in a cylinder row direction.

An oil supply device configured to supply oil to a turbocharger of an engine includes a first oil pump, a second oil pump, a first valve, and a second valve. The first oil pump is coupled to a bearing unit of the turbocharger via an oil supply path, and configured to supply oil to the bearing unit. The second oil pump is coupled to the bearing unit via an oil discharge passage, and configured to suck oil from the bearing unit. The first valve is provided in the oil supply path. The first valve is switchable from a connected state to a disconnected state when the engine is to be stopped. The second valve is provided in the oil discharge passage. The second valve is switchable from a connected state to a disconnected state when the engine is to be stopped.

A turbocharger for supercharging an internal combustion engine includes: a bearing housing which accommodates a bearing supporting a rotational shaft of the turbocharger; an oil discharge port for discharging lubricant oil stored in an internal space of the bearing housing; an air pocket formed in the oil discharge port or an oil discharge pipe connected to the oil discharge port; and a communication flow passage which brings the air pocket and the internal space into communication.

A blow-by gas device of a supercharger-equipped engine includes a blow-by gas passage that introduces blow-by gas into an intake passage via a positive crankcase ventilation (PCV) valve. A supercharger has a supercharger rotor provided integrally with a rotation shaft rotatably supported on a bearing part. A space communicating with the bearing part is connected to a communication passage. The communication passage guides the blow-by gas into the space.

A marine engine comprises a powerhead having an engine block, a cylinder head and a crankcase containing a crankshaft. Operation of the marine engine causes rotation of the crankshaft. A crankcase cover encloses the crankshaft in the crankcase. A supercharger is on the crankcase cover, the supercharger being configured to provide charge air for combustion in the powerhead. The supercharger comprises a charge air outlet for conveying charge air from the supercharger for combustion in the powerhead. A drainage port drains lubricant from the supercharger to the crankcase.

A centrifugal compressor includes: a housing; an impeller rotatably disposed within the housing; a rotational shaft connected to the impeller; and a bearing member supporting the rotational shaft in the housing. An oil flow passage through which oil flows is formed in the housing. The oil flow passage includes a lubricating oil passage through which the oil flows as lubricating oil to be supplied to the bearing member, and a cooling oil passage through which the oil flows as cooling oil for heat exchange with a fluid compressed by the impeller. The cooling oil passage is configured so that the oil flows into the cooling oil passage as the cooling oil without passing through the bearing member.

An engine includes: an exhaust manifold 7 close to one of left and right side surfaces of an engine; a turbocharger 60 having an exhaust-side inlet connected to the exhaust manifold 7; and a rocker-arm-chamber-integrated intake manifold 8 being disposed on an upper surface of a cylinder head 5 and integrally including a rocker arm chamber 90 and an intake manifold 6. The intake manifold 8 has a wall 101 dividing the rocker arm chamber 90 close to the one of the left and right side surfaces of the engine 1 and the intake manifold 6 close to the other of the left and right side surfaces to isolate the rocker arm chamber 90 and the intake manifold 6 from each other. The rocker arm chamber 90 has, in its upper portion, a positive crankcase ventilation device 69 protruding therefrom and being configured to return blowby gas to an intake system. The positive crankcase ventilation device 69 has, in its side surface, a blowby-gas discharge port 67 connected with a gas conduit 68 through which blowby gas is delivered to an intake-side inlet of the turbocharger 60.

A cylinder head assembly for an internal combustion engine includes a cast cylinder head having at least one oil gallery, a turbocharger housing integrally cast with the cylinder head, and a turbocharger cartridge assembly configured to be inserted into the turbocharger housing and including at least one bearing rotatably supporting a shaft coupled between a compressor wheel and a turbine wheel. A lubricant supply system having a lubricant passage formed within the turbocharger housing is configured to supply oil from the at least one oil gallery to the turbocharger cartridge assembly to lubricate the at least one bearing.

A straddle vehicle includes: a prime mover; a hydraulically actuated main clutch; an oil control valve unit; a power unit case accommodating at least the main clutch; an oil pan mounted beneath the power unit case; a clutch-dedicated pump; a primary filter disposed in an oil passage between the oil pan and the clutch-dedicated pump; and a secondary filter disposed in an oil passage between the clutch-dedicated pump and the oil control valve unit. The primary filter and the secondary filter are mounted on a bottom surface of the power unit case and covered from below by the oil pan.