Mine runs .0030"/.0027" clearance. Its run a 50/50 mix of JR1 5w20/ 5w30 for yers. Pressure runs 50@idle/80@7000. Oil temp is normally around 150 degrees. Same babbit cam bearings for over 950 passes. Springs are 310/805 psi
Doug

Yes exactly....For me, its a volume issue. I have been killing #7 & #8 bearings for years when they starve for oil....Wondering what other folks due differently. Obviously, an accumulator might be in order as well. So roller cam bearings and maybe sleeved lifter bores sounds like what I have been missing.

Maybe a better oil pump or and more oil volume in the oil pan

He's not lacking oil in the pan. I think he runs a 10-12 quart pan already. I think he runs the good Milodon external pickup style pump also.

Going to run 13 in the pan after we tested the oil height at 12, we still had room....

Driven GP-1 10/30. 508 BB 650HP and agree with RICRAW very clingy oil. I used to run the Valvoline VR1 10/30 and wasn't unhappy with that but really like the GP-1. Check out Lake Speed's videos on YouTube. some good info there.

At this point, if you had a 55 gallon drum for an oil pan, it wouldn't matter. I don't think the amount of oil you have in that motor is gonna matter...it's where the oil is going (or isn't going) that's the issue.

I run 5W20Wt Valvoline petroleum base oil in my hot street cars, I've seen 12 HP gain going from 30Wt to 5W20Wt with the same oil temps
Oil does two things for our motors, it lubricates and cools, look at all the current production cars running really thin synthetic oils and living

I think it all depends on your engine. My 426 hemi solid roller 7-quart pan and melling HV pump has more than enough pressure with 10w-30 mobil 1.

With my 55MM roller cam bearing cam. I run Penn Grade 10W30 with a Melling high volume oil pump that I took apart clearanced, ported and polished. Also run bronze bushed lifter bushings with push rod oiling and the RBRE rocker system that has built in spray bars. Also a 10 quart Milodon flat bottom top fuel/funny car oil pan with Milodon external pick up. and a 3 quart Accusump (just in case). No issues on the street with hundreds of miles or strip.

"I have been killing #7 & #8 bearings for years when they starve for oil"

In the interest of not being totally useless, thought I should mention during the WP/MP/Royal Oak boring era I did replace two iron blocks because the drill bit
for the main oil feed broke through the side of the main structure.

This type of defect would create the type of pinhole internal leak that could
cause a similar problem.

At the time, the oil feed hole was 5/16", which is pretty huge given the lack of material in the area of the main structure above the crank, where the hole passes through.
I never found out whether the hole was to print, or a world famous engine builder's idea.

It's not hard to repair with a tube pressed in..... but a messy job to confidently find it.... as the whole thing has to be assembled, pressurized, and viewed with the oil pan off, to look for leaks where there shouldn't be.

Might not need exotic parts or machine work, might be something wrong with the block

OK, back under my rock I go.