Low oil pressure when warm, Crushed. Finally get to drive the car and the idiot light comes on Options

[trojanhorsepower]

A bit of background.
My engine (short block) was assembled wrong by a "professional" about 23 years ago before I got it. When I got it I finished assembling the rest of the motor and found the cam timing was wrong. After several posts and help from Jake Raby we found the cam gear had been installed backwards and a new hole drilled to make it fit. At that point Jake had me split the case, mic the cam and crank and get the numbers off the bearings. All that checked out. I rereassembled the engine and everything went well. Now 23 years later I have the engine in the car and it runs pretty well. (using Brad Penn 30wt break in oil) Except the oil pressure idiot light comes on at idle after the engine warms up. Maybe 10 min of driving. Now based on the threads I have read and the books I have there are no components that affect the oil pressure once the oil is warm? The check valves are for cold oil correct? Hot oil should just bypass the oil pressure bypass valves?
So I will change the oil for 20w50 VR1, but really am I just grasping at straws? What can actually cause this other than bearing wear? An out of spec oil pump? Anything else?

Thanks for the help

Peter

[Chad911sc]

I have been, and still going through the same thing. It’s very frustrating and patients is a virtue. I replaced my oil pump while still in the car the first time because it had a very steady drip coming from between the pump and case. It can be done safely, but it’s true the room to work is limited. I used the cast iron oil pump cover with a piece of 400 grit paper and WD 40 to fix the leak. Mine leak was due to an imperfection in the case, and it came out and it sealed nicely afterwards. I didn’t notice my low idle oil pressure until after that. I had noticed the leak after breaking the cam in on my 2056 as well. My oil pressure however, would follow the rpm’s up to 5500 no problem, but once it got to 220, my idle pressure was falling down to 4lbs. I bought the Tangerine oil valve in hopes that it was the problem as well, but the same thing happened after reaching temps. And I had a 30mm pump in it because I have external filter and cooler/fan combo.
So I finally bit the bullet and pulled it out of the car and disassembled the engine to find my middle bearing was wiped out. The other bearings looked perfect. I took my crankshaft to my best friends house who builds mud truck race engines and he put it in his V block set up and my crank was out of round .008 thousands. This crank had been sent to a recommended local machine shop to be checked out completely. The owner said everything was perfect with it and it only needed a polish. I was super happy and on my way to build the engine. Long story short, there is only a couple things from what I understand that can explain this problem. Oil pump clearance and bearing clearance.
I’m hoping yours is oil pump interference issue. Before pulling the engine and tearing it all down, you could try to put a CB 26mm pump in there. Thats what I had in mine initially, and it fit tightly. If it doesn’t work, it will only cost you your time and less than a hundred bucks. If you want to do it, send me a pm and I can send you details and pics of how I did it in the car.
Best of Luck!!