Need some help - loosing oil pressure at high rpm's

[madmaxx]

I think I figured it out!!!!!!!

1) The oil pump RV is set at 65 psig. Bottom line with the plumbing and current oil filter motrocraft fl1A (not fl1HP) the pump RV lifts as it is supposed to and the oil is going into the pan instead of the engine resulting at the 50 psig above 4K rpm.

The last engine was "identicle" to this one. 3 years ago i did some testing of different oil filters to determine the pressure drop across them when cold. I wanted to see if the oil filter internal rv in the filters would lift. I had the same gauge set up as I do now but that oil pump releived at 79psig!!!!!!! vs 65 psig on this engine. I found my notes last night. There 15 psig right there.

When i bypassed the oil cooler the other night the oil pressure dropped from 50 psig to 46psig vs 43 psig with the oil cooler.

I am 75% sure if I jack the rv screw on the oil pump i will get my 50 plus oil pressure above 5K rpm since it wont be releiving. Mellon gave me some bad info, he indicated max pressure was 70 psig, bullsheet, i got 79 psig on the last one same model etc.

Now why the fluctuation in pressure the step change between 4k and 4.4K. I credit this preminsion to my new found expert from SCOF. I can't get on the forum but this is probably better. The guy is an engineering wonder with engines. He substantiates his theory with physics. He educated my on oil filters. He explained the better oil filters like the FL-1Hp is alot more than the burst strenght of the can or o-ring it is the filter media does not collapse under higher pressures!!!!!!!!!! That never dawned on me and they sure dont advertise it that way. I remeber cutting open the Royal Purple filters, synthetic filter media encased with a ss expanded metal to maintain medai spacing!!!!! The FL1A (i never used before now but went cheap this time) has paper media with no support. I theorize at 4K plus rpm where the oil pump is hitting maximium flow (high volume) and pressure the media is deforming causing additional pressure drop across the filter!!!!! If my rv was set at 79 psig it would still happen but i would not notice as teh pump would drive the oil through it until the media collapsed or a hole was ripped in it.

Path forward. Obtain new spring from mellon and install in oil pump. change filter to Royal Purple ( i like better than fl-1hp) but fl-1hp is a good filter.

now its going to rain for 4 days so who knows when i can try it!!

PS

I cannot beleive the builder has returned all my emails (I am blown away) and it was him that told me make sure you use a FL1HP and it stuck with me and helped me to come to the aforementioned conclusion!!!


Now to be an asshole. Another install fukup. I guarantee if what i theorize above is true this has been like this since day one. Car was delivered with 100 miles from the reciept dont tell me they didnt see the low oil pressure on the gauge. Probably blamed on engine builder. builder doesnt know if you are going to jam a oil cooler and use pos filters.

Installer did wrong motor mounts - same as my last one
Installer used wrong thermostat. - same as my last one

i feel better now