Q is for Quandary

[FElony]

I have this '69 I picked up a couple years ago that I'm starting to mess around with. It's 428 runs OK, but oil pressure is low. Warm, 25 at idle and creeps up to 50 at 2500+. Should not be driven?

From what I know about the engine, the original pistons, crank, and rods are swinging around in a 390 cheater block, as the original block was damaged back when the car was running Stock Eliminator. I don't want to risk grenading the original parts due to oil problems, but not sure if 25-50 psi is in "threat" territory. Don't want to take this engine apart until I have secured a proper dated C-scratch for the components. Can toss a 390 in and beat on it. ?

[sixty9cobra]

From what I understand 10 psi per 1000 rpm is acceptable. That all depends on oil viscosity etc. Sounds ok to me my 464 has 25 at idle and 55 at 2500 and that's with  all the good stuff.

[Drew Pojedinec]

25psi hot idle is low?
Just about any FE I've ever owned with a stock oil pump does that, or am I missing something?

[jayb]

R is for Run it!  Not to worry, IMO...

[FElony]

OK, evidently I was misinformed as to what low pressure is. I am an idjit, as evidenced by the amount of blood squirting out of me at the moment, as I only I could injure myself with the BACK of a knife. Truly pathetic. Thanks you guys for the, uh, feedback that, uh, hey lookie i need to vacuum under my desk, cuz, is this a furrball, what's a C6AE-D intake, oh the colors...

[Drew Pojedinec]

Don't feel bad, I had a pickup truck engine that would idle at 4psi hot.

I was just happy there was oil pressure.....  ran like that forever.  (obviously not ideal, nor performance oriented).

[BigNate]

My tired old 352 ran at 10 PSI at idle and 30ish when up on RPM.  This bugged me so I went to 40 weight then 20-50 - and now it runs at about 15 PSI at idle 45 PSI up on RPM.  I figured I'd be building something bigger anyway and if the thicker oil somehow shortened the life of the engine it would be an excuse to get off my duff and build something.

[shady]

yes, what is with the bleeding. I cannot work on anything anymore with out bleeding. the good thing is I never feel it, so usually I don't even know what the hell I did. I can turn the simplest project into a bio-hazard.

[machoneman]

Gotta ask: is the oil pressure gauge run off the OEM Ford electrical sender? How old is that sender? Or is it a mechanical gauge?

[My427stang]

As said, 25-50 is great, run it!

You can play with different oil weights if it makes you feel better, but it'll be fine there

[jayb]

yes, what is with the bleeding. I cannot work on anything anymore with out bleeding. the good thing is I never feel it, so usually I don't even know what the hell I did. I can turn the simplest project into a bio-hazard.

 ^^^^
This!  LOL

[FElony]

Gotta ask: is the oil pressure gauge run off the OEM Ford electrical sender? How old is that sender? Or is it a mechanical gauge?

Yep, one of the things that crossed my mind was the accuracy of an aftermarket mech gauge that may have some congealed oil in the line or even inside it. Experiences?

As said, 25-50 is great, run it!

You can play with different oil weights if it makes you feel better, but it'll be fine there

I checked the kitchen pantry, and I have Valvoline VR-1 in both straight 50 and 20-50 flavors. I have no idea what's in there now, so I guess I should do a change.

yes, what is with the bleeding. I cannot work on anything anymore with out bleeding. the good thing is I never feel it, so usually I don't even know what the hell I did. I can turn the simplest project into a bio-hazard.

If I were a totally honest, forthright guy (and not someone known by several local courts by the very nickname I use here), I would admit to skewering myself with a paring knife whilst opening a package for lunch. However, to keep my reputation as macho vermin intact, I will claim that I was indeed using a 10-inch Bowie knife to remove the gaskets from a pair of factory chromed Mercury pentroofs. So there.

[machoneman]

Gotta ask: is the oil pressure gauge run off the OEM Ford electrical sender? How old is that sender? Or is it a mechanical gauge?

Yep, one of the things that crossed my mind was the accuracy of an aftermarket mech gauge that may have some congealed oil in the line or even inside it. Experiences?

Possible it is. You could take off the line and run some compressor air through it. If plastic, a replacement kit with the proper brass ends and compressible sleeves is pretty cheap.

'Course if the gauge itself is faulty, all bets are off. One last thought: some old school vacuum gauges could also test fuel or oil pressure if one rigged up fittings to the engine side and the gauge itself. If you have one, just for laughs it can be run under the hood w/o driving the car with a very short line just to see how it compares to the dash gauge.