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318/390 priming oil pressure 110 lbs

Posted By: merpar

318/390 priming oil pressure 110 lbs - 03/15/24 04:31 PM

I built a 318 stroker 390. Priming the oil system with drill on low rpm it has 110 lbs oil pressure. Am running 5-30 break in oil. Anyone know how much to cut off spring to lower pressure? All by bearing clearances are .0025.
Posted By: B1MAXX

Re: 318/390 priming oil pressure 110 lbs - 03/15/24 04:34 PM

I would get a new spring ...stock one...before cutting
Posted By: varunner

Re: 318/390 priming oil pressure 110 lbs - 03/15/24 04:41 PM

FYI,
on my 383 with a high volume pump, cold idle was 95 psi. Replaced spring with one from a standard pump, pressure cold was 55 psi
Posted By: B1MAXX

Re: 318/390 priming oil pressure 110 lbs - 03/15/24 04:45 PM

What cup plug was used the hi press spring usually put out about 75.

The stock cup plug is very thin wall, If you use a standard 5/8 cup plug it usually pushes it up to 90.
Posted By: stumpy

Re: 318/390 priming oil pressure 110 lbs - 03/15/24 06:35 PM

The pressure will drop down some after break in.
Posted By: TJP

Re: 318/390 priming oil pressure 110 lbs - 03/16/24 12:50 AM

Originally Posted by B1MAXX
I would get a new spring ...stock one...before cutting


iagree
Posted By: Cab_Burge

Re: 318/390 priming oil pressure 110 lbs - 03/16/24 02:08 AM

Pull the oil pump bypass valve out and make sure it has a small block valve in it (with several holes in the spring cup part) and not a BB type with no holes wrench scope
there was a bad batch of new Melling's or the other manufacturer years ago that had the wrong bypass valves in them whiney rant puke scope
Posted By: GODSCOUNTRY340

Re: 318/390 priming oil pressure 110 lbs - 03/16/24 08:42 PM

Boy, I must have got one of those from Rock Auto, rebuilt a 340, started it on the run stand and it instantly pegged the pressure gauge, blew the seal from the oil filter and ballooned the Wix filter. Glad it was on the run stand and not in the car. It actually ruined my gauge as it would read 20 more PSI than it should have.
Posted By: rickseeman

Re: 318/390 priming oil pressure 110 lbs - 03/16/24 11:45 PM

I would assume the bypass valve is stuck.
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