Yep!

 

I recently switched oil filters from an AC PF 454 to an AC PF 1218 (because the 1218 is larger). Afterwards, my oil pressure went from 35-40 PSI cold to 50-55 PSI. Once the oil warms up, idle oil pressure drops to around 20 PSI, just like it was with the 454. Oil filters really do have a major influence on pressure...

 

Yep... my bad, serious mix up there... what I should have said was a more restrictive filter will LOWER the oil pressure reading on stock gauges.


the spring isn't realy set for 60psi... it's ~60 psi at the GAUGE reading (probably closer to 75psi at the pump)... with a stock oil filter. I saw 65psi at times on my stock engine with a large filter. And I'd imagine it is possible to overwhelm the pump bypass if say the oil was cold and viscous and someone went to high rpms (volume delivered may be more than the bypass can reject leading to pump pressures even over 75psi). p

Also, the pressure seen at the gauge may vary based on the FILTER'S BYPASS setting (~10psi differential which could show up at high RPMs/volumes, so the gauge at WORST only reads pressure 10psi less than the pump is putting out). If the filter bypass is even weaker (say 5psi) or even fails in an open position, you'll see 75psi on a perfectly normal pump/engine (other than the bad oil filter bypass). If the oil filter bypass is stiffer than normal (and excessive pressure differential accross the filter can build up), at high rpms you could see lower oil pressures in the bearings/gauges.

If the gauge pressure isn't pegging out the deep end you could probably rest easy that there isn't a "blockage" somewhere.

Like I mentioned though... i feel oil analysis is the only way to tell if there is excessive wear somewhere. Pressure itself seems too subjective/variable on its own (viscocity variations, leakage/clearances differences, rpm dependance, pump bypass, filter bypass, etc...)

 

I also run big filters... that may be why I get higher gauge readings than others. More filter element = less resistance to flow = higher pressure at gauge?

 

Yeah, I prefer a Canton pan with my HV pump (or sort-of HV... it's only 10% over stock... much like the BBC gears).

I run the Melling Select 10552. You might want to reconsider the use of those M55HV in the future... they changed the castings and there are reports of the thinner casting cracking. The Melling Select series (like the 10552) still have the older, thicker neck on them to prevent cracking under high vibrations/rpms.

 

I agree with this, and along the same line of thinking too many people are relying on the factory dash gauge which is more of a "suggestion" than fact in my opinion - need to hook up a good mechanical gauge for true readings

 

This particular thing doesn't matter to me either way. I am just saying I bought the car this way. Dash shows 130,000 miles on it. Has 10W40 oil in it so you would think with those 2 things the pressure would kind of be down. but its not. As I stated I have a Autometer 2 5/8 oil pressure gauge on it. Reads the same as the dash. Even tried a different one just to see if my Autometer was junk. Same thing.


So basically what some are saying is that if is the case and someone put a Hi volume pump in this and it has the stock pan on it, it won't last right??

 

I also have the canton pan with the mellings 10552 pump, it is a great combination for any motor.