Engine Lubrication System

Oil from the oil pan (6675) is forced through the pressure-type lubrication system by a rotor-type oil pump. A spring-loaded relief valve in the oil pump (6600) 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 (6303) is drilled from the main bearings to the connecting rod journals to lubricate the connecting rod bearings (6211).

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 (6A618).

The main oil gallery intersects all of the valve tappet bores supplying pressurized oil to the hydraulic valve tappet (6500). 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 (6565). In this position, the drilled hole in the ball end of the push rod is indexed with a drilled hole in the rocker arms (6564), 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 (6049) and cylinder block (6010).

Excess oil in the push rod chamber drains back into the oil pan through openings along the cylinder block.

Oil Pump

The oil pump is of the rotor type with an inner rotor which turns inside of an outer rotor ring which is off center. It is driven off the camshaft (6250) by the distributor drive gear through an oil pump intermediate shaft. The pump is mounted to the bottom of the cylinder block inside the oil pan and contains a pressure relief valve. To deliver sufficient pressure and volume at low rpm, it has to be designed to provide excess pressure and volume at high rpm. To prevent damage or excess oil consumption, the pressure relief valve drains off the excess pressure and volume at high rpm.

Oil Pan

The oil pan is of the pressed-steel type and is attached to the bottom of the engine (6007).

It serves as a reservoir for engine oil and receives oil after it has been pumped through engine bearings and orifices to be reused by the engine.

The oil pan allows some oil cooling through the pan walls.

Engine Lubrication, 4.9L Six-Cylinder

Engine Lubrication System

Item	Part Number	Description
1	—	Oil Passageway (Part of 6010) to Oil Pressure Sending Unit
2	6600	Oil Pump
3	87838-S	Plug, Hex 3/8-18 x 0.42
4	—	Oil Orifice Gear (Part of 6010) to Camshaft Gear and Crankshaft Gear
5	6211	Connecting Rod Bearings
6	6333	Crankshaft Main Bearings
7	6261	Camshaft Bearings