Ok Before I start taking this motor back down and start looking. Anybody run into this yet. Let me say I never in my years ever ran into this.
This is in my 1980 pickup. I tore down a 1990 350 TBI block, If anybody has in the TBI era, There about the same as the 96' an up vortecs. They have the thrust plate for a roller cam (even though they are Flat tappet.) they have the flat spots to hold the lifter keepers with spider. Any how, I put roller cam with vortec heads on it. Carb intake HEI distributor. Fired it up. An no oil to lifters. I rev up only 40 lbs. oil pressure. Should be at least 60. Never in my life has this happened before. Lifters should oil up in 30 seconds.. Any intelligent thoughts or has this happened to anyone EVER LOL Oh and yes little plug is under the main bearing cap And the 3 in front and back and etc..

 

If you’re still looking for an answer...

Remove the distributor and drive the oil pump with a primer tool and drill. A corded drill would be best as it will reach higher RPM while under the load of driving the pump.

While driving the pump, look into the distributor bore to determine if oil is reaching the top of the galley that feeds oil to the cam. A helper to drive the pump or look into the bore would make it easier.

If there’s oil reaching the top of the galley, try to verify the clearance and seating depth between the distributor shaft notch out (just above the drive gear) and the bore in the valley. The notch out is where the oil galley from the filter and galley to the cam bearings meet. Oil pressure to the top end isn’t wholly dependent on this being sealed, but excessive clearance between the shaft body and bore (or the seating depth being off) could be preventing the pressure from building adequately to lubricate the lifters & rockers.

 

X2. Reprime the oil pump, as Gumby stated, you should have oil actually everywhere. Did you prime the pump initially?

 

That was the best explanation ever saw on the internet about that. Ok one thing if you don't mind. I have a old distributor shaft I've used before now it modified and does not seal when spinning the pump. But I've used before and oil usually flows like crazy out that top oiler hole against the shaft. But on this occasion it didn't flow out there like usual. Made me really question that to. Oil presure gauge was slugish high speed and high rev of motor top was 40lbs. What you think.. Thanks

 

I know the type of distributor you’re talking about but I don’t know how oil gets into the shaft bearings - I would guess there’s an additional galley to direct oil into them but even if that’s true I don’t know if it came directly from the block or fed through to the bore in the intake manifold.

I also don’t know how the overall dimensions compare to the dimensions of the newer distributor that would be in the 1990 block.

Even assuming the distributors are the same size, and that oil should be pumping into the distributor shaft, the lack of oil flow from the hole in the distributor still indicates a flow problem.

A couple of other tests I thought of are to remove the oil filter and drive the pump to check for volume as opposed to pressure. Oil flows from the pump to the filter before it moves on to the bearings, so a low volume of flow to the filter indicates a pump related problem.

Another test would be to adapt an air hose to the filter bung and supply low pressure air to the top end of the engine. This way you can have the distributor fully removed and check for a blockage between the filter and top end.

 

What sort of oil pressure are you getting at idle? 40 PSI at freeway speed is normal for an engine with lots of miles, but a good rebuild or new motor ought to be in the 50-60 PSI range if the bearings are all the correct size. It depends on the motor too. My old 258 Jeep motor only put out 40 PSI at high speed and drop to 30 PSI at idle. but it was an inline 6-cylinder motor, not meant for high performance, but lots of torque.