Question on oil pressure relief valve

[papastruck]

I've been searching and I swear the answer is on here, but I give up. My question is: Is there a way to definitively answer whether the oil pressure relief valve needs to be replaced or shimmed, like a published measurement or visible sign of wear?

This part of a larger question of somewhat low oil pressure , ~6psi hot idle, ~30 running hard, and I thought I'd use this measurement to help determine whether there's a larger problem in the engine. Thanks for any info.

 

[jonathan]

i think icanfixall wrote something about this before

 

[papastruck]

He's written extensively on the topic; I just can't find the post where he talks specifically about the valve. I know he shimmed his, but I can't remember whether there were any tolerance measurements.

 

[papastruck]

This was the closest I've found. No measurements, but it does raise the question of whether I should even worry about my numbers.

http://www.oilburners.net/forums/showthread.php?p=138684&highlight=pressure#post138684

 

[icanfixall]

I shimmed my new spring by making 70 thousands shims from stainless steel washers. These spring rub the side of the regulater. After many hours of run time the spring looses some of its wire thickness... That lowers the available spring tension so overall pressure drops accordingly.. The bad part is we have no repair parts. The rear header is expensive but thats the only way to make it right. Then shimming that.... Its plenty of work... I don't feel you really have a low oil pressure issue....

 

[papastruck]

I shimmed my new spring by making 70 thousands shims from stainless steel washers. These spring rub the side of the regulater. After many hours of run time the spring looses some of its wire thickness... That lowers the available spring tension so overall pressure drops accordingly.. The bad part is we have no repair parts. The rear header is expensive but thats the only way to make it right. Then shimming that.... Its plenty of work...

That was my suspicion. Oh, well.

I don't feel you really have a low oil pressure issue....

That's much better news. Thanks Gary!

 

[icanfixall]

Let me say this about how you might feel looking at a gauge.... I have three Rotunda pop testers for injectors... Two work fine and one is mostly just a parts item... So a few days back I was "testing" both of them and one showed 2050 lbs and the other was 1850 on the same injector... So I swapped the pressure gauges and the high and lows followed the gauges... So my question is what is the correct pressure reading off either gauge..... I really can't say for sure but... I know all my injectors will be the same pressure on the same gauge setup... When I first installed my rebuilt engine 5 years ago I calibrated the tps to 1.2 volts... The trans seemed differant but I ran it anyway... Finally I had no od and all the shifts got very soft... So I rechecked the voltage and found it 1.2 volts just like I set it... Then I thought I should test the voltmeter on a known battery voltage... It tested way low so now I'm thinking either my meter is crap or the battery is crap... Bought another voltmeter... Tested it on my battery and it was 12.4 volts... So.... I had a bad digital voltmeter and didn't know it... Cost me a trans.... So do you believe what your seeing when you test or read a gauge..... You need to have a known baseline to start with... Is you gauge really that accurate telling you the pressure is what it is.... I can buy a $400.00 calibrated pressure gauge and know for sure what I have but is that practical.... Nope... Not at this moment..... Even if I had 8 new injectors what would my pressure be... Non't really know but whatever it was I would have a baseline to start from... Wondering what the po did to your engine is the big question. What you have now is just that. Your bearings probably have clearanced themselves a bit but its running and no noises are happening... You could take a oil sample and see what meatal may be in the oil too....

 

[papastruck]

True, true. I'm fairly confident in the reading because I've gotten the same readings from two different aftermarket gauges. I also wonder how the placement of the sender affects things - this one's up where the line t's for the turbo. At any rate, the oil sample seems like a logical step before getting too worried about it. That's again, I always appreciate your input.

 

[Knuckledragger]

If memory serves, I remember more than once seeing that these engines operated on about 7 psi hot at idle, not much more running. They live on volume, not pressure. As long as you have plenty of oil splashing around inside, things should be OK.