0390295 EVINRUDE GEAR & BUSHING,Forward

Illustration 1 g01244919
Main oil pump and lubrication system schematic (typical example) (1) Main oil gallery (2) Left camshaft oil gallery (3) Oil gallery for the piston cooling jet (4) Oil gallery for the piston cooling jet (5) Right camshaft oil gallery (6) Adapter (7) Sequence valve (8) Sequence valve (9) Oil filter base (10) Oil cooler (11) Oil cooler bypass valve (12) Oil pump relief valve (13) Engine oil pump (14) Elbow (15) Suction bellThis system uses an engine oil pump (13) with three pump gears. The pump gears are driven by the front gear train. Engine oil is pulled from the pan through suction bell (15) and elbow (14) by engine oil pump (13). Suction bell (15) has a screen in order to clean the engine oil.There is an oil pump relief valve (12) in the engine oil pump. The oil pump relief valve controls the pressure of the engine oil from the engine oil pump. This allows the engine oil that is not needed to go back to the inlet oil passage of the engine oil pump.The engine oil pump pushes oil through engine oil cooler (10) and the engine oil filters to main oil gallery (1) and left camshaft oil gallery (2) in the cylinder block. Engine oil cooler (10) lowers the temperature of the engine oil before the engine oil is sent to the filters.Engine oil cooler bypass valve (11) allows engine oil to flow directly to the filters if engine oil cooler (10) becomes plugged or if the engine oil becomes thick enough to increase the oil pressure differential by 180 20 kPa (26 3 psi).Engine oil filters are located on the right side of the cylinder block. The oil filter base (9) also has one bypass valve for each filter.Clean engine oil from the filters goes through adapter (6). Part of the engine oil goes to left camshaft oil gallery (2). The remainder of the engine oil goes to main oil gallery (1) .Left camshaft oil gallery (2) and right camshaft oil gallery (5) are connected to each camshaft bearing by a drilled hole. The engine oil goes around each camshaft journal. The engine oil then travels through the cylinder head and the rocker arm housing to the rocker arm shaft. A drilled hole connects the bores for the valve lifters to the oil hole for the rocker arm shaft. The valve lifters are lubricated at the top of each stroke.The main oil gallery is connected to the main bearings by drilled holes. Drilled holes in the crankshaft connect the main bearing oil supply to the rod bearings. Engine oil from the rear of the main oil gallery goes to the rear of the right camshaft oil gallery.Sequence valve (7) and sequence valve (8) allow engine oil from the main oil gallery to go to both piston cooling jet galleries (3) and (4). The sequence valves begin to open at approximately 130 kPa (19 psi). The sequence valves will not allow engine oil into the piston cooling jet galleries until there is pressure in the main oil gallery. This decreases the amount of time that is necessary for pressure buildup when the engine is started. This also helps hold pressure at idle speed.
Illustration 2 g01244972
Piston cooling and lubrication (typical example) (16) Piston cooling jetThere is a piston cooling jet (16) below each piston. Each cooling jet has two openings. One opening is in the direction of a passage in the bottom of the piston. This passage takes engine oil to a manifold behind the ring band of the piston. A slot (groove) is in the side of both piston pin bores. This slot connects with the manifold behind the ring band. The other opening is in the direction of the center of the piston. This helps cool the piston and this supplies lubrication to the piston pin.
Illustration 3 g01245011
Turbochargers (typical example) (17) Oil supply lines (18) Oil drain linesOil supply lines (17) send oil from the rear adapter to the turbochargers. Oil drain lines (18) are connected to the flywheel housing on each side of the engine.Engine oil is sent to the front and rear gear groups through drilled passages. The drilled passages are in the front housing, the rear housing, and the faces of the cylinder block. These passages are connected to left camshaft oil gallery (2) and right camshaft oil gallery (5) .After the engine oil flows through the lubrication system, the engine oil returns back to the engine oil pan.