bgrizz

The motor is brand new and has a slp oil pump on it. The oil pressure at cold was 45 psi and hot was 30 psi. To go along with the low pressures when at 3k rpm hot the pressure was only able to reach 45 psi. This is nowhere near the pressure i was getting on my old motor with a ported ls6 pump. I figured i had a pinched o-ring on the pickup tube, after an arduous tear-down i discovered a perfectly round o-ring with zero signs of being crooked or pinched. So.... i'm at a standstill. Could the pump itself be bad? What could cause the pressure to be just a little too low?

thanks for any advice.

Mike94ZLT1

iTrader: (3)

You're fine... The newer motor has looser clearances than the factory one. 10 psi per 1000 RPM is fine. If you're really that worried about it put a Melling 10296 pump in it, but I wouldn't lose any sleep over the pressure you have.

Also, try a different oil filter. I've got a K&N on mine, and my oil pressure is MUCH higher than with a Delco filter!

98RedBird

iTrader: (77)

Agreed, it's most likely looser clearances. Your numbers aren't anything to get upset over. However, changing filters may show a higher pressure but it's not really changing anything. It's kind of just band aiding what you're seeing. Like using a heavier weight oil...

bgrizz

The pressure doesn't seem to climb fast with rpm. It being a new shortblock, i haven't taken the revs past 4k. Even at 4k the pressure wasn't even 50 psi. I'm well aware of the 10 psi per 1k rpm rule of thumb, but this is just cuttin' a little close for my liking. I'm just worried because i've heard horror stories about bearings and oil starvation with lower oil pressures.

Mike94ZLT1

iTrader: (3)

According to the GM tech manual, an LS1 needs 7 psi at idle to float the crank. Seeing as you are about 4 times that... I'd say you are fine.