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Just a broad observation that parallels many I have read.
Appx 15-25 psi oil pressure at hot idle, engine at full operation temperature.
Add about 15-25 psi for a stone cold motor at fast idle, like when you first start it, so that's 30-45 psi (I've seen higher psi than that under those conditions with 40, 20/40 and 20/50 weight oil)
My 440 that has unknown hours/miles on it is a stock short block as far as I can tell with 6 pack forged crank and 6 pack rods, stock flat pistons with valve relief notches, and the unique 6 pack offset weighted harmonic balancer.
In South Louisiana, I run Valvoline VR-1 20/50 year round since the "warmer months" which is about 8 out of 12. If VR-1 was available in a 20/40 I'd run that in the colder 4 months, but usually I don't drive it much then anyway.
My oil pressure runs around the numbers stated, around 50+ psi stone cold fast idle, then at full operating temp (185°-195°) at 850-900 RPM idle it drops to about 25 psi and increases to around 60-65 driving around.
If it ever drops below 20 psi I would be concerned.
I installed a mechanical oil pressure gauge in the 65 GTO years ago because the factory gauge sucks and the 421 it turned out had a really bad crank bearing. At full operating temperature, the oil pressure would drop to 5 psi at 800 RPM idle speed, much lower than cold pressure. It was trying to tell me it had a bad bearing. I had a performance oil pump installed when we had it rebuilt, but I am cautious about "high volume" and especially "high pressure" oil pumps. High pressure can be moderated with the bypass pressure spring, but I'd rather get it close than have that spring bypassing too much. Too much pressure and it takes away from the "cushion" that oil provides bearing gaps. Too much volume could tend to drain the pan and push a lot of oil "up top".
Just my opinion and experience. I'm not an engine builder nor expert.
Appx 15-25 psi oil pressure at hot idle, engine at full operation temperature.
Add about 15-25 psi for a stone cold motor at fast idle, like when you first start it, so that's 30-45 psi (I've seen higher psi than that under those conditions with 40, 20/40 and 20/50 weight oil)
My 440 that has unknown hours/miles on it is a stock short block as far as I can tell with 6 pack forged crank and 6 pack rods, stock flat pistons with valve relief notches, and the unique 6 pack offset weighted harmonic balancer.
In South Louisiana, I run Valvoline VR-1 20/50 year round since the "warmer months" which is about 8 out of 12. If VR-1 was available in a 20/40 I'd run that in the colder 4 months, but usually I don't drive it much then anyway.
My oil pressure runs around the numbers stated, around 50+ psi stone cold fast idle, then at full operating temp (185°-195°) at 850-900 RPM idle it drops to about 25 psi and increases to around 60-65 driving around.
If it ever drops below 20 psi I would be concerned.
I installed a mechanical oil pressure gauge in the 65 GTO years ago because the factory gauge sucks and the 421 it turned out had a really bad crank bearing. At full operating temperature, the oil pressure would drop to 5 psi at 800 RPM idle speed, much lower than cold pressure. It was trying to tell me it had a bad bearing. I had a performance oil pump installed when we had it rebuilt, but I am cautious about "high volume" and especially "high pressure" oil pumps. High pressure can be moderated with the bypass pressure spring, but I'd rather get it close than have that spring bypassing too much. Too much pressure and it takes away from the "cushion" that oil provides bearing gaps. Too much volume could tend to drain the pan and push a lot of oil "up top".
Just my opinion and experience. I'm not an engine builder nor expert.