Oil pump relief valve

[66furys]

I have read the threads on the subject and am not happy. My old 383 ngine runs at just over 25psi. I have put diesel fuel in the pan, have changed to heavier oil and no change. I want to shim the relief valve. Any one tried this and if so what type thickness have you used. I have done this on tractor hydraulics, and think that I may need about 20 thou washer. Thoughts appreciated.

 

[413]

Yes I’ve shimmed with a flat washer. It works.

But you may have more problems. Like a plugged pickup with valve stem seals or timing chain plastic teeth.

or just may need a new oil pump, easy to change.

 

[57fury440]

If it is the oil pump it is really easy to change.

 

[gyknot]

I agree its easy to get to and change, but 25 psi is more than enough oil pressure too. I realize most people seem to like to see 40-60 psi but its not needed.
Just my 2 cents worth.

 

[57fury440]

25 psi is okay for around town. I wouldn't be happy with that on the freeway doing 65 to 70 mph.

 

[413]

Does this engine run on all 8 cylinders? Are we sure a lifter didnt come out of the bore? seems like it wouldn’t even have 25 then.

Depends on the rpm if 25 is enough on the freeway, but it’s not right, it is trying to tell of a problem somewhere.

bad pump
clogged pickup
loose bearings.
0w20 oil