? Oil Pressure
Thread Starter
Drifting
Joined: Mar 2009
Posts: 1,461
Likes: 361
From: Monson MA
? Oil Pressure
Fresh rebuilt L79 sbc. I converted to roller cam. I'm running 10w40 Gibbs HR5 oil. At startup cold my pressure is a solid 80psi. At operating temperature I run 70psi at idle. I am not comfortable with this. How would I lower pressure?
Last edited by twinpack; Feb 28, 2021 at 08:10 PM.
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,597
Likes: 7,046
From: New Or-leens Loo-z-anna
Google says to temporarily install a mechanical oil pressure gauge ( high pressure tubing runs from engine pressure port to temporary oil pressure gauge) to make sur the dash gauge is reading correctly.
If the mechanical gauge and the dash gauge read about the same, either the oil filter is clogged or the oil pump pressure relief valve is clogged/stuck closed.
Change the oil filter..if the pressure remains high...clean the oil pressur relief valve or replace it.
If the mechanical gauge and the dash gauge read about the same, either the oil filter is clogged or the oil pump pressure relief valve is clogged/stuck closed.
Change the oil filter..if the pressure remains high...clean the oil pressur relief valve or replace it.
Burning Brakes
Joined: Dec 2017
Posts: 1,043
Likes: 414
2023 C3 of the Year Finalist - Modified
Did you change the oil pump during the rebuild?
if you replaced it with a high volume or high pressure unit then I think the numbers you have are expected.
If it’s a stock type oil pump and the pressures were lower before the rebuild I would question the clearances of the mains.
how to fix? If you did use a high vol/press pump, drop the pan and swap in a stock type.
if you replaced it with a high volume or high pressure unit then I think the numbers you have are expected.
If it’s a stock type oil pump and the pressures were lower before the rebuild I would question the clearances of the mains.
how to fix? If you did use a high vol/press pump, drop the pan and swap in a stock type.
Last edited by randallsteel; Feb 28, 2021 at 10:26 PM.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
Go to Summit and search Mellings Oil Pump SPRINGS. No need to swap the whole pump, but it will still need to come out and be placed in a vise.
A little drift pin in the pump contains the spring inside. The springs are sold by color codes and that represents the PSI.
It is NOT high oil pressure that makes the valve covers leak. It is NOT high oil pressure that makes the china wall leak or other gaskets.
Myself, I would let it go. Your pressure is a whole lot better than the alternative.
A little drift pin in the pump contains the spring inside. The springs are sold by color codes and that represents the PSI.
It is NOT high oil pressure that makes the valve covers leak. It is NOT high oil pressure that makes the china wall leak or other gaskets.
Myself, I would let it go. Your pressure is a whole lot better than the alternative.
Safety Car
Joined: Sep 2005
Posts: 4,226
Likes: 643
From: Orange County Ca
Go to Summit and search Mellings Oil Pump SPRINGS. No need to swap the whole pump, but it will still need to come out and be placed in a vise.
A little drift pin in the pump contains the spring inside. The springs are sold by color codes and that represents the PSI.
It is NOT high oil pressure that makes the valve covers leak. It is NOT high oil pressure that makes the china wall leak or other gaskets.
Myself, I would let it go. Your pressure is a whole lot better than the alternative.
A little drift pin in the pump contains the spring inside. The springs are sold by color codes and that represents the PSI.
It is NOT high oil pressure that makes the valve covers leak. It is NOT high oil pressure that makes the china wall leak or other gaskets.
Myself, I would let it go. Your pressure is a whole lot better than the alternative.
I would fix it.
Last edited by Sayfoo; Mar 1, 2021 at 04:19 PM.
