Engine Lubrication

4.9L Lubrication System

Oil from the oil pan is forced through the pressure-type lubrication system by a rotor-type oil pump. A spring-loaded relief valve in the oil pump limits the maximum pressure of the system. Oil relieved by the valve is directed back to the intake side of the oil pump. From the oil filter, the oil flows into the main oil gallery. The oil gallery supplies oil to all the camshaft bearings and crankshaft main bearings. The crankshaft is drilled from the main bearings to the connecting rod journals to lubricate the connecting rod bearings. Oil from the floor of the valve tappet chamber is fed through a drilled passage to lubricate the distributor shaft, bushings and the oil pump intermediate shaft The main oil gallery intersects all of the valve tappet Excess oil in the push rod chamber drains back into bores supplying pressurized oil to the hydraulic valve the oil pan through openings along the cylinder block. tappet. A reservoir at each valve tappet bore boss traps oil so that oil is available for valve tappet lubrication as soon as the engine starts. When the hydraulic valve tappets are on the base circle of the camshaft lobe (valve closed), the oil hole in the hydraulic valve tappet is indexed with the oil gallery, and oil flows into the plunger. Oil is also metered through the metering valve (disc), through the oil passages in the push rod cup, and it flows up the hollow push rod. in this position, the drilled hole in the ball end of the push rod is indexed with a drilled hole in the rocker arms, and the oil lubricates the upper valve train bearing areas. Excess oil is returned to the oil pan through drain holes along the side of the cylinder head and cylinder block