Is that a HP Fram? or regular? I have sucked a regular fram enough to restrict, guys say they have with HP filters but I never did, for chits and giggles swap to K&N or Wix racing and see, could be simple as that

I was going to bring the same thing up, try a wix or napa gold filter, if that does not change it, might try plugging the spring cooler lines(think that what was said you were running) and see if that changes it, if you are loosing OP at WOT throttle usually a pan, drain back, lines issue. what pan are you running, smitty(articfriends) had the same issue recently on his dyno engine he's flogging and came down to drain back/pan

try adding the 11th quart of oil. there could be so much that hasn't made it back to the sump yet that the level is low.

His issue sounds diff than the issue im having with my junk ass canton pans. Mine starves for oil at 6000, oil pressure starts dropping from 80 or so to 35 or 40 at a very quick, erratic rate. You start adding oil it goes away but its NOT steady when it does it

What is your thought that the Canton oil pan is causing oil pressure loss on the dyno?

Ive seen similar issues to these though, it always comes down to volume of oil needed/supplied vs oil temp/hot viscosity vs what requirements dictated by . all clearances/controlled leaks motor has
Example: my 540 had similar clearances as described, i had some 5 w 40 or something to that effect in after dynoing at crocketts. Was only in for last couple pulls so i left it in motor. Going down river w oil at 220 degrees ehen you would lean on it it did EXACTLY what dougs oil pressure does. Took a couple rides though before i saw it, cruising at 55/60 psi at 3400, lean on it to 5000 u der boost and watch oil pressure steadily drop (not erratic at all). Cut filter open, changed oil, no metal, went to 20/50 and nomlonger did it unless i ran oil too long.
Ran oil too long cause oil pressure drop? In MY case motor was procharged, tune was fat, oil got gassed up and thinned out. I think thats why it did it with the thinner oil but not right away. Stuff was gassed up when i changed it so was even thinner than rated. I started doing my own tuning and got tune better and never saw much contamination in oil after that.

Your setup is just like mine except for the pan and block. I use a block adapter that does away with the relief valve then I use a filter with a relief valve in it. What block adapter are you using?

Oil pickup is becoming uncovered and sucking air, i previously ran 14 qt hardin and would run 11 or 12 qts and never had a issue. If a pan is a 10 qt pan, and manufacturer says put 9 in pan plus filter and you need 10 in pan to not starve motor, literally 1/2 qt less oil and your turning bearings to copper? Im perplexed by it, the trap doors are fairly stiff and barely open 1/4 or less of their swing. I left it like that as i figured it was how it was designed but i feel now that the oil is having hard time getting to the pickup. When i first ran this engine with this pan problem was worse, pulled heads and doubled size of drain back path, it was small but i had previously ran this rngine with same bearing clearances, lifters, pump, heads etc with only thing being different was the pan. Again, a good pan shouldnt starve motor the minute oil is 1/2 quart below max full, no way all of a sudden top end of motor is holding ALL of the oil. Going to mod a pan soon and try it with 8 qts oil, if mods work ill keep the pans, if not they are going down the road

My pan is
this one from Summit Racing..
Has a couple trap doors but nothing all too fancy...

https://www.summitracing.com/parts/sum-g3607/overview/
https://static.summitracing.com/glob....jpg?rep=False
Pickup...
https://static.summitracing.com/glob....jpg?rep=False
https://www.summitracing.com/parts/sum-g3623/overview/

Yeah.. mine too..

http://www.cpperformance.com/images/...e/625-7914.jpg
http://www.cpperformance.com/images/...e/14597_4_.jpg

http://www.cpperformance.com/p-14597...gen-4-bbc.aspx

and I AM running an HP filter.. Cut the last one open.. couple metal flakes still (long story) but looked ok....
hopefully it IS just the cheap STP oil causing it.. ;)