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I have been doing some learning on SBC oiling and came across some diagrams that appear to show oil going to the filter from the pump getting a partial diversion to the rear main bearing.
Do I just not see it? Or is there a bit of the oil going to the thrust bearing before the rest goes to the filter?
White Font Auto part Engineering Parallel
 

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Race it, Don't rice it!
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The picture isn't clear enough. It's confusing looking from the front. There is a plug right there though. The one most people refer to "under the cap" and a sometimes a hot topic when its left out. `
Try this one......Looking at the back
 

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Pump to filter there are two bypasses here the first is that the pump has an integral bypass that limits maximum system wide pressure the factory setting is usually around 60psi. The second is in the oil filter itself This is flow control to insure the engine receives adequate oil flow. This is a differential pressure valve that opens or closes based on pressure loss inside the filter. If the pressure loss is high as it will be with cold thick oil or a plugged dirty filter the pressure oil delivered is routed around the filter directly into the engine. The damage from dirty oil is considered by the engineering staff as less an issue that damage from no oil.

Between the vertical feed passage up the back of the block to the main oil passage that runs above the cam there is a plug between this out bound passage from the filter to the pressure passage from the pump, If the plug is left out no oil goes through the filter. This is a left over from the early mid 1950’s engines that did not use the throwaway filter can. The early engine had filtration as an extra cost option that was the old time replaceable element in a pressure kettle design. The “modern” throw away filter was a modification to the block which left much of the original passages in the block thus the need for the plug when it was redesigned to a throw away filter. The filter bypass I reference in the previous paragraph is now contained within the filter itself.

The vertical passage up the back of the block feeds the rear cam bearing first. From here another vertical passage feeds the rear thrust main with a horizontal cross feed that supplies the lifter galleys with pressure oil.

The horizontal passage that is seen in the valley if the intake is removed runs the length of the block. At each main bulkhead a vertical drilled passage feeds the cam bearing then the main bearing. At each cam bearing station these is a machined slot in the cam bearing boss to carry oil around the bearing which upon installation closes the slot to make a circular passage behind and around the cam bearing’s steel shell. The main passage continues to the front of the engine ending in the timing case behind the cam gear. The lifter galleys on both sides also extend the length of the block and terminate in the timing case with plugs behind the cam gear. All three of these passages also terminate on the back of the block with plugs. With the timing case cover and cam gear removed at the front and the flywheel or flex plate removed from the rear these three passage terminations are visible. The right side lifter galley is intercepted by the distributor housing thus the dual bosses in the lower distributor housing, this forms a passage on that side of the engine, thus the need to be sure the distributor is seated before attempting to fire the engine.

The lifters have a band to pass galley oil around them, if you measure the for the volume of the lifter‘s waist band you will find that the open area of that waist is at least the same area as the lifter oil galley passage diameter.

Bogie
 
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