SSMOKEDLS1

iTrader: (3)

Ok so we put a friends motor together a few days ago and I'm stumped about why it's losing oil pressure. At cold idle pressure is at 60, and about 30 hot after driving it for awhile. Seems normal right? Well after we did a hard pull through the gears it fell to like 10psi at idle and just shy of 40 driving under rpm... It wouldn't come back up till the car cooled down. I changed the pick up o-ring and still the exact same symptoms... Think it could be the tsp ported pump? Or what? I'm stumped..

noice

Did you forget the oil barbell? Are all the plugs in? Have you tried a mechanical gauge?

ljsracing19j

Are you sucking the pan dry? You said it had a ported pump. (guessing HV) and it only occured after hard pulls. Let it "cool down" which lets the oil run back to the pan...

OldCobraGuy

iTrader: (2)

This sounds about normal for an engine with some loose clearances. The pressures you have are not dangerous...they are good enough. What weight oil are you using? You can always use a heavier viscosity and that should help. But this sure sounds like loose bearings, thrust, etc.

JPH

iTrader: (2)

Last motor that I worked on that did that needed new crank/rod bearings. But it could be a oil pump problem or a crack/broken weld in the oil pickup tube also.

raven154

iTrader: (14)

Sounds like the same problem I had with my LS6. All the mains were toast. Previous owner of the engine built it and had no clue what he was doing apparently.

cobrakillincamaro

I had the same issue and it was the o-ring. I understand you just replaced it but they can be a pain in the butt. I just replaced mine again and haven't had an issue sense.

A.R. Shale Targa

iTrader: (2)

I thought the O-ring being torn or unseated causes no or very little pressure
and noisy valvetrain. I'm betting the OP just has loose main clearances. They
need to be tighter than GEN 1 sbc because of the expansion rate of the
alloy block. IIRC 0.0016-0.002 is the target. Having close to 3 thousandths
will act exactly as the condition stated.

mondols1

iTrader: (2)

i had a section of my o-ring missing (about 20%) and my oil pressure dropped to about 10lbs when hot from about 40lbs. i replaced the pump and 0-ring and its at 60lbs+ cold and 40lbs hot now.

wildcamaro

iTrader: (15)

Unless u have a bigger oil pan capacity, that hv pump is draining the oil pan before the oil from the topend can make its way back down to the pump...thats why I wouldnt run a hv or ported pump unless I had a 6.5 qt pan or higher...just my experience

OldCobraGuy

iTrader: (2)

That's not the problem here. He's low all the way through the rpm scale. He's shows all the classic symptoms of being too loose.

genesisjoelton

Hey man I had the exact same problem and my o ring was pitched so I would try that first

OldCobraGuy

iTrader: (2)

I could certainly see that if it's sucking air. Any signs of foaming?

SOMbitch

iTrader: (8)

You can bandaid it with some 50wt while you are saving up....