LOW OIL PRESSURE

[55chevy]

Here's my delima... I just got done rebuilding the engine in my Nova and drove it to work today for the first time. It runs good. Oil pressure: It has around 60lbs at startup.. after warm it carries around 40-45lbs all the time (while driving) but when I come to a stop and it idles in gear it quickly drops to 10lbs or less.. if I hold it at around 1100rpm it'll hold around 20lbs but soon as I let it go back to idle it drops back down. ... what is WRONG???? http://www.yenko.net/ubbthreads/images/graemlins/confused.gif and how long can I expect this engine to last doing this??? http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif I'm out of money AND patience with this thing... http://www.yenko.net/ubbthreads/images/graemlins/crazy.gif ...........help

[camarojoe]

I have always heard that as long as you have at least 10 psi per 1000 rpms, you have sufficient oil pressure.

[55chevy]

[ QUOTE ]
I have always heard that as long as you have at least 10 psi per 1000 rpms, you have sufficient oil pressure.

[/ QUOTE ]

This engine just seems to be carrying pressure differently than all the other SBCs I've had.. This being the only one I've completly rebuilt myself (so far) I thought maybe I missed something somewhere.. (internal leak??..blow by?? something??).. The pressure goes up and down quickly with the rpms. .. Or am I just paranoid with my own work? http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif

[Pantera]

I.m betting on a weak oil pressure by-pass spring it the oil pump.

Pantera

[YENKO DEUCE REGISTRY]

Did you install a new high volume oil pump, or the standard one?

[budnate]

sounds like a bad or wrong application oil pump, I accidently stuck a BB oil pump on a SB once as a kid and it did about the same thing, was told by the parts guy it was pumping everything up ontop and starving the pickup... http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif sorry Ed probably the last thing you want to do is deal with getting at the pump for a look at it.

Bud.

[55chevy]

It's a new Melling pump.. I'm pretty sure it's just the stock replacement.

[Mr. T]

On all the SBC engines I have rebuilt in the past, there has only been one time that I witnessed sparatic oil pressures at different rpm's. It was an easy fix, and believe it or not, the oil pressure sending unit was faulty. I installed a new one, and the oil pressure at idle increased by 10 psi.

[55chevy]

Think I should try a better oil pressure guage first?
I got the high dollar $9.99 Harbor Frieght triple guage package special in use at the moment... http://www.yenko.net/ubbthreads/images/graemlins/crazy.gif

[Pantera]

Come by and I will loan you a SW gauge. It still does not sound like a gauge problem but you just never know. Like I told you in the email this morning to check it out first.

Pantera http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif

[rsatz28]

For what it's worth, my 302 does the same thing running 10-40 oil...and I know I have a Melling high volume pump. I picked up about 5 psi across the board when I went to a 20-50 oil.

[55chevy]

That could be a cause. I'm running 10-30. I think the oil pressure is ok in the motor. I was just a little paranoid on my first trip out with it I guess. Anyway, now thats the least of my problems.. now my tranny is going out!.. Slipping like crazy on the way home today.. I think it's 4 speed time..

[70 ls6 convert]

Did you plastic gauge the rod and mains 1.5 to 2.5 is good ,did you replace your cam bearings ? if thats all good,after you check your oil pressure with a manual gauge and its still bad,its your oil pump.