Gray Ghost Silverado

iTrader: (1)

Hey guys, I stick around on performance trucks quite a bit so I hardly post up much over here on the tech board.

I did a search and didn't find anything useful on this topic so I figured you guys might be able to help me figure it out.

What I have is an L76 that has not been stroked, although it runs a combination of Callie's crank, Callie's rods, and Diamond Pistons. Bearings are Clevite coated 1X on the mains (clearanced out at .023 for boost) and Clevite standard coated rod bearings (clearanced out at .025) it also runs a Moroso High Volume oil pump with the Hi-Pressure spring.

I noticed that this thing during high load at whatever RPM is always about 2-3psi less on the gauge for oil pressure as compared to the same RPM while normally accelerating.

For instance it hot idles with about 35psi, and normal acceleration at 3,000 rpm will show 57 pounds. Hi-load it shows 54 psi. WOT at 6,500 is always right at 70 psi though.

Is this normal behavior of an LS engine? It sounds fantastic, no knocks or rattles, nothing in the oil, and it builds oil pressure instantly on cold starts so..... I dunno?

Thanks in advance.

Gray Ghost Silverado

iTrader: (1)

Haha holy crap! No guesses? Maybe I asked a retarded question?

wildcamaro

iTrader: (15)

As rpm raises so does oil pressure but I've never heard of oil pressure in the 70s...are you running 50 weight lol?

Gray Ghost Silverado

iTrader: (1)

Haha no sir just a bad ******' oil pump, and that is at 6,500 rpm. 5W-30 Mobil 1

Lonnies Performance

iTrader: (16)

Sounds odd, but entirely possible.

Usually low pressure at high prm is seen as a windage problem or the pan being sucked dry, but at 3K, not something typically heard of. 3# though would not worry me anyway.

Gray Ghost Silverado

iTrader: (1)

That's reassuring, and I meant to say it happens across the entire RPM band so I'm not sure. I forgot to mention that I installed Durabond cam bearings, which as I understand it have significantly more clearance than standard GM bearings. Perhaps with more engine load the cam walks a tiny bit and reduces the pressure. It's still got plenty of pressure which doesn't bother me at all, I've just never seen/watched an oil pressure gauge this close and noticed that kind of behavior.