A method of modifying the oil cooling system of a diesel engine includes the steps of removing the original equipment liquid-to-liquid heat exchanger and installing a manifold having a configuration adapted to match the mounting configuration of the oil passages of the original equipment liquid-to-liquid heat exchanger. The manifold has an oil outlet port directed to a remotely mounted oil cooler. The manifold also has a water passage having a configuration that is adapted to match the mounting configuration of the water passages of the original equipment liquid-to-liquid heat exchanger. The water passage causes the entirety of the flow of water to be discharged back to the water cooling system of the engine where it is circulated by the water pump through the water cooling passages in the engine.

An internal combustion engine includes an engine lubrication fluid system with a main rifle for distribution of filtered lubrication fluid to a plurality of engine components through a plurality of secondary rifles connected to the main rifle. The system also includes a bypass for bypassing the filter in response to certain engine operating conditions. The bypass is connected to at least one of the secondary rifles so that unfiltered lubrication fluid is not provided to certain engine components under filter bypass conditions, and provided directly to certain other engine components for which unfiltered lubrication fluid is less problematic.

An engine assembly includes a small air-cooled engine and a dry sump lubrication system including an external oil reservoir, wherein the dry sump lubrication system has an overall oil capacity that provides at least five hundred hours of engine oil life.

The lubrication mechanism comprises a vertically disposed crank shaft, a laterally movable piston, a connecting rod connecting the crank shaft and the piston, a cylinder barrel housing the crank shaft and the piston, a crank case containing the crank shaft together with the cylinder barrel, a cylinder head forming a combustion chamber, the combustion chamber connecting to a piston movable part end face of the cylinder barrel, an oil filter, and an oil filter installation member in which the oil filter is vertically installed, and the oil filter installation member includes a lubricant detour structure.

An internal combustion engine includes an engine lubrication fluid system with a main rifle for distribution of filtered lubrication fluid to a plurality of engine components through a plurality of secondary rifles connected to the main rifle. The system also includes a bypass for bypassing the filter in response to certain engine operating conditions. The bypass is connected to at least one of the secondary rifles so that unfiltered lubrication fluid is not provided to certain engine components under filter bypass conditions, and provided directly to certain other engine components for which unfiltered lubrication fluid is less problematic.

An engine assembly includes a small air-cooled engine and a dry sump lubrication system including an external oil reservoir, wherein the dry sump lubrication system has an overall oil capacity that provides at least five hundred hours of engine oil life.

A bypass apparatus for lubricant in an unregulated pressurized gearbox including: a block including a lubricant inlet in fluid communication with a pressure relief valve, wherein the pressure relief valve diverts lubricant into the gearbox or into an oil filter, wherein lubricant is returned to the gearbox when the lubricant is cold and/or pressure at the pressure relief valve is high to reduce damage to the gearbox caused by high pressure during a cold start, and when the lubricant temperature increases and the pressure is reduced the pressure relief valve closes and lubricant enters the oil filter.

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.

An oil filter assembly is disclosed for a machine, such as an internal combustion engine, that has an oil output port and an oil input port. A mounting plate may be fixed with an outer enclosure and may be adapted for securing to the machine. The mounting plate may be further adapted to conduct oil from the machine into a peripheral portion of the outer enclosure, and then returning oil from a central portion of the outer enclosure back to the machine. Oil may pass from the peripheral portion to the central portion through a primary filter having a first porosity. A pressure-actuated valve may be fixed fluidly between the peripheral portion and central portion of the outer enclosure. Oil may pass through the pressure-actuated valve only when an oil pressure differential between the peripheral portion and the central portion of the outer enclosure exceeds a predetermined threshold pressure. A secondary filter may have a second porosity greater than the first porosity, and may be fixed fluidly between the pressure-actuated valve and the central portion of the outer enclosure.

The invention relates to a pressure oil filter system for a hydraulic transmission, in particular for a motor vehicle transmission, comprising at least one oil pump which can be actuated as required and which has a pressure side and a suction side, a pressure line to a consumer and at least a first oil filter which is arranged at the pressure side of the oil pump in the pressure line, wherein means for damping pressure surges during intermittent operation of the oil pump are provided in the pressure line upstream of the first oil filter in the flow direction of the oil.