My take on the oiling system crossover tube for the small block

nm9stheham said
Uuuuuuh... I would not shim it like that at all.. 3/16" shim will push the pressure waaay up. I'm quite serious about that. Started shimming pump springs a while ago and 3/16" seems way out of line. Sure you got that number right?

What is the point of paying for a blueprinted pump if they are not going to test and set up for a specific pressure relief? If the spring is correct (72 psi), then shimming that much will push it well beyond 100 psi, I bet.

Ya know, I might be wrong about the 3/16" part. From what Doug over at Precision mentioned on the phone was that he does not use the high pressure springs, he uses shims with the stock spring to bring the pressure up. I'm sure he has his reasons of doing it that way. I am certain he does a flow/pressure test.

Duane said
Just to clarify, does he have a high volume pump or not.
I see nothing wrong with 26 psi hot at idle. It is the maximum pressure that is in question correct. If this motor does not have a high volume pump and makes 45-50 psi, then just switching to a high volume melling with a 72 pound spring will boost pressure
Easily to a satisfactory pressure.

I have a HV pump on the engine right now. Haven't done anything else to it, no HP springs, no shims. Stock out of the box Melling HV pump from Napa.

We'll find out in a little while how it acts with the new pump. I have to change out a leaking rear main seal, so while I'm there I'll try out his pump, not gonna hurt any.

Take a look.
Precision Oil Pumps