HOME 3.4 OIL FLOW GENERAL in the crankshaft to lubricate the front connecting rod bearings. The engine oil serves two purposes. First, the oil lubricates all of the metal to metal parts that are in motion relative to each other. Second, the oil cools the engine, specifically, the pistons. 4. From the cam drive side main bearing, the oil is routed in two directions: See Figure 3-1 . As the oil is warmed to normal operating tem- perature, the oil is scavenged from the sump at the screened pick up (1) by the oil pump (2). a.
Oil is routed up to the cam drive triple gear bushing (9) where oil is routed along the shaft to the water pump impeller.The oil also flows to front cylinder head through an oil sending unit (10) which shuts off the oil pressure light when oil pressure reaches 13.8-34.5 kPa (2-5 psi). The oil passages continue on to the intake and exhaust cams (13) lubricating the cam journals through grooves in the bearings and to the secondary cam chain tensioner (12). The oil pump (2) pressurizes the oil and the pressure maintains the flow of oil through the engine. The oil flows through a bypass valve and through the oil passages to the oil filter (3).
If oil pressure exceeds 88 psi, the bypass valve is activated, rerouting oil back through the suction side of the oil pump. The filtered oil flows into the oil lines up and over the top of the radiator/oil cooler assembly (via oil line) and down to the left side of the oil cooler (4). Flowing through the cooler, the cooled oil is routed up and over the radiator/oil cooler assembly (via oil line) and then down to the oil fitting (5) on the front of the crankcase. b.
The second set of passages from the cam drive side main bearings lead the oil flow to the primary cam chain tensioner and up to the secondary cam chain tensioner, the rear cylinder head and the rear intake and exhaust cam journals. From the primary cam chain tensioner the oil also branches to the rear piston jet to cool the underside of the rear piston. The final passages from the cam drive side main bearing routes oil back to the transmission and clutch where the oil lubricates and cools the transmission input and output shafts. At the crankcase oil fitting, oil is routed to three passages: 1. Oil entering the passage (6) on the water pump side lub- ricates the right main bearings.
The oil flows in a groove in the main bearing then through a drilled hole in the crankshaft to lubricate the rear connecting rod journals. 2. of the pistons. . Returning oil to the sump (19), the rear 3. See Figure 3-2 in a groove in the main bearing then through a drilled hole 6. The oil in the front cylinder head drains down the cylinder head drain passage (18) to the sump (19). 2009 VRSC Service: Engine 3-9 7) supplies oil to th oil to cool the un cam drive side p in bearing. The o 5. See Figure 3-3. Ret e front cylinder head drain derside primary gear and cl inder head also drain assage shaft gearset (16) w il flows gears and then drai