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

[madmaxx]

Update

1) definetly not the rod or main bearings. They were perfect and new ones were too! No difference
2) checked oil pump internal clearance. Rotor to end plate perfect
3) bypassed oil cooler no difference union between two fittings which bolt to cooler, still using braided limes a d remote filter
4) reset oil pump Rv spring. About perfect now sucess there
5) pulled gauge fitting and reducer off block. Used mirror to inspect block orfice. Full of
fuking Teflon. Spent three hours digging it out. I have every pick known to man now.
6) installed new gauge with new tubing. Not much difference in pressure fluctuation. One time revving in driveway I let off gas in neutral and the fuking gauge increased in pressure wtf! I have the first engine where spinning the oil pump slower gains pressure.
7). Started raining. Going to hook up gauge at filter housing again and compare to car gauge.

The absolute last thing I can try is bolting filter to block and that is a long shot since shortest filter is 4" adapter is 1/2 and total space is 4.5". Lol

They way I have run the sheet out of it trying to diagnose this would have failed any worn component. It's screams!

No more removing the oil pan there is absolutely nothing more i know to do in there.

Somebody mentioned a Venturi effect near gauge that appears to be the closest thing at this point.

[Jac Mac]

Have you tried removing a couple of quarts of oil to lower the oil level and reduce the possibility of windage induced aeriation, some times too much oil is worse than not enough..

[madmaxx]

Yes I have manipulated the oil level high and low. Might be an anomaly in the block port for the pressure gauge.

anybody know where I can buy a dummy gauge

[Jerry Clayton]

who in there right mind have the audacity to mention an venture effect?????????? and also I bet whoever it was probably doesn't ever use Teflon paste or Teflon tapr on plumbing fittings

[Jac Mac]

Originally Posted by Jerry Clayton

who in there right mind have the audacity to mention an venture effect?????????? and also I bet whoever it was probably doesn't ever use Teflon paste or Teflon tapr on plumbing fittings

That was you Jerry & you have a point. Its the major reason why you see higher oil pressure readings in a cleveland block ( which has the oil pressure fitting at the rear end of the main gallery ) versus the lower readings on a windsor block ( which has the pressure fitting at the front just in from the filter pad in an area where the main flow goes past the fitting as opposed to flowing directly at it), both motors run the same size oil pump gears, & yes there are differences in bearing sizes etc.

A bit hard to prove in a windsor unless its an aftermart block with priority oiling that will allow shifting the oil gauge to the rear, but easy to check out in a clevo by swapping from front to rear.

[Jerry Clayton]

and Teflon is for frying pans, not oil, fuel or brake systems

[madmaxx]

Originally Posted by Jerry Clayton

and Teflon is for frying pans, not oil, fuel or brake systems

Teflon taoe is for idiots!!!!! I pulled chunks out which resembled a hair bAll from a cat.

[olddog]

Quote from post #9 in this thread.

Originally Posted by olddog

If it was bearings causing a drop in the engine, you should also see a drop in pressure at the cooler inlet. This tends to say there is a restriction somewhere after the cooler inlet. Perhaps a tear inside a line has a flap folding over at higher flow rates.

The fur ball of teflon tape certainly could move at high flow rates and close off flow like a flap. Or it may just always restrict flow to a small amount, and there is not enough flow to the bearings to keep the oil from overheating.

The question now is: are there more fur balls and where?

[madmaxx]

I have two identicle gauges plumbed inside car. Oil cooler bypassed!!!!! with a union all hoses and remote mount still in place.

Oil at 100C and 5500 rpm I get 68 psig on remote filter mount after filter and 52 psig at block. Identicle gauges read at same time driving down road. 16 psig fuking pressure drop in the hoses to block. remember my one pressure gauge is on the back side of the remote filter after filter and housing.

I have got to get rid of the fuking hoses!!!!! How the fuk do you get the remote manifold off the block there not enough room for a wrench and it appears you need a gigantic socket. the problem is still in one of the 10AN hoses or they are just to small.

the pressure reading on the remote filter location would keep going up if I didn't hit the rev limiter solid as a preacher dick.

for grins the pressure drop across the hoses when cold at idle (800 rpm) is 10 psig!!! get rid of the useless oil coolers and plumbing they are destroying your engines.

[Caprimaniac]

Originally Posted by Gaz64

Your cooler and lines aren't big enough.

As he said. Should be AN10 in oil system, someone told me....

Can you use the 90 deg filter adapter?

Also try removing the oil cooler to see if that helps, if larger lines do not so. You have a thermostat plumbed in?

Maybe oil pump "whipps" the oil like some water pumps do at high revs????

It doesn't seem like your pickup/ pan is a issue.
However; at higher speeds- more sucking- more vacum around the pickup and the pickup glue to the floor. There goes your lower pressure at higher revs.

After all your oil PSI looks OK even if it drops; doesn't seem too low.

[olddog]

Max I understand your frustration.

If you can get an oil pressure reading at the connection where the oil returns to the engine, we will know if the pressures drop is happening in the line, or if the drop is inside the engine. It is possible that there is another teflon fur ball in an oil gallery inside the engine. Let's hope it is the external line.

[madmaxx]

Had to Christmas shopping wtf!!! what about me!!! LOL

To remove the oil filter manifold adapter and screw a filter on the block would be beneficial but way to much work and not a permanent resolution since I have to use a tiny filter.

New path forward is get 24" piece of 10AN braided hose and fitting and plumb from remote oil filter bracket/ holder back to oil filter manifold. If that works it is a permanent solution and it bypasses the oil cooler (which is bypassed) (4) 90 degree fittings and 72" of 10 an braided hose.

I agree 12AN is the ONLY WAY to have an oil cooler. I have no desire for an oil cooler as I block them off. If the aforementions work I will have an oil fooler have the look without the price!!!

I really have no concerns about the drop to 52 psig as I have been intimate with this engine and it is pristine and through my endless testing have run the living sheet out of it. In addition I know for a fact I am not pump air either another concern.

Found out my oil temp gauge doesn't work, I thought the oil was only getting to 50C but when I put the sending unit in boiling water it only showed 50C!!!! I have no doubt it been getting to 100C.

Once I get the correct motor mounts I can really run it thought it paces. Hit 120 accidentally as I was staring my plethora of oil gauges in third running up to 5500 rpm. that should probably stop.

Did some quick pressure drop calcs using water and just straight pipe. 12An is the correct size which at 8 gpm has a velocity of 7.87 ft/sec which is what you usually size lines too. 10AN is 11.86 ft/sec. pressure drop was 4.1 psig for 10 vs 1.33 for 12 AN.
To convert to 12AN from filter mount to remote filter mount and back is $165.93, to just run a 2 foot return from remote filter to block with the existing 10AN is 61.97 since you only do one side. fittings are expensive!!! If you are doing a huge round trip to cooler and back you have to use 12AN for a quick reach around you can probably get away with the 10AN.

All my calcs were straight pipe with no bends modeled with water not oil.

[Rick Parker]

If you are using the Large Black (heavy) Remote filter block (?) the internal holes in the large "NUT" may be partially blocked. There are much better designs.



I got rid of this, and cleaned up the line routing with an adapter like this in a size 10.

http://www.aviaid.com/shopsite_sc/st...oler-adptr.htm Bottom of page, no internal sharp corners or edges to reduce flow.

[PLDRIVE]

Rick i believe thats a Canton billet aluminum adapter. Its not heavy (relative to other parts) and they can be rotated 360 Degrees without effecting oil flow.

Mark

[madmaxx]

Your engine is immaculate wow!!!!!! Yes that is what I have. I have not removed it yet. Hit the bottle last night and need to recover




QUOTE=Rick Parker;1276095]If you are using the Large Black (heavy) Remote filter block (?) the internal holes in the large "NUT" may be partially blocked. There are much better designs.



I got rid of this, and cleaned up the line routing with an adapter like this in a size 10.

Remote Filter and Cooler Adapters at Aviaid Bottom of page, no internal sharp corners or edges to reduce flow.[/quote]

[YerDugliness]

Originally Posted by madmaxx

The absolute last thing I can try is bolting filter to block and that is a long shot since shortest filter is 4" adapter is 1/2 and total space is 4.5".

Originally Posted by madmaxx

......I have to use a tiny filter.

Is Ford's FL1A a direct crossover to a Fram PH8A?

If so, IIRC the Fram PH47 (or it might be the 48) is a shorter filter, but...

You might want to try a Bosch 3312....very short...much shorter than even the Fram PH47(?) and fit onto my replica while a standard PH8A would not (but the shorter Fram would!)

I could get a measurement if it would make any difference, but it sounds like you want to keep the remote mount...that's a lot of work and very expensive if a shorter filter will do the job, unless you need to feed an oil cooler, but I've been reading the thread since you started it and I know you aren't a fan of the coolers....

I have had no trouble with the Bosch and it is by far the easiest aftermarket filter I've ever tried to fit into my replica....high efficiency, too!

I shoehorned a 351C into a '72 Mercury Comet (Ford Maverick) and there was no room for a filter...used a "pancake filter", the Oberg Tattletale model, worked a charm and didn't cost me to replace the filter every time I changed the oil. Next time I do that I'll locate the Oberg up in the fishmouth...Oberg says it will offer an 8-degree drop in oil temperature, too.

Instead of going with AN stuff, I had some hydraulic lines made up at my local auto parts store...one of the fittings always leaked, very unacceptable...will go to the expense of AN stuff next time, that's for sure.

Cheers!

Dugly

[madmaxx]

Dito post

[madmaxx]

[quote=madmaxx;1276563]Thanks. I let you know. Not much progress hope to look at it this weekend. My mentor pointed me towards some interesting information with respect to bearing clearances, oil viscosity shear etc. I also stumbled across some bearing info on the mains which lead me to believe don't know for sure as builder don't have info or won't supply that it may have larger bearing clearances than "usual" when built.

I have no way to measure accurately as I don't trust plastigauge, my guess is the mains are .0025 to .003 as opposed to .002 to .0023. Found a graph on bearing clearance and oil leakage. For every .0005" oil leakage is .5 gpm per main. It was in dart big block main clearance. I know mine isn't a big block but still relevant on increased bearing clearance and oil leakage.

Oh with my new $ gauges which are hyper sensitive drop happen linear from 4 to 5.5k rpm. Not step change, delay was in the dash gauge.

Reducing pressure drop across the plumbing is great but I bet I would just move the drop to a higher pressure. Like 65 psig to 59 psig.

Solution may be heavier weight oil or oil that doesn't shear as easy. Remember we are only talking 6 psig.

This emphasis the need for a builder like blykins who supplies a complete build Manual eliminating the guess work.

With oil warm, 60c, coolant at 80c pressure drop only 1 psig.

[madmaxx]

[quote=madmaxx;1276564]

Originally Posted by madmaxx

Thanks. I let you know. Not much progress hope to look at it this weekend. My mentor pointed me towards some interesting information with respect to bearing clearances, oil viscosity shear etc. I also stumbled across some bearing info on the mains which lead me to believe don't know for sure as builder don't have info or won't supply that it may have larger bearing clearances than "usual" when built.

I have no way to measure accurately as I don't trust plastigauge, my guess is the mains are .0025 to .003 as opposed to .002 to .0023. Found a graph on bearing clearance and oil leakage. For every .0005" oil leakage is .5 gpm per main. It was in dart big block main clearance. I know mine isn't a big block but still relevant on increased bearing clearance and oil leakage.

Oh with my new $ gauges which are hyper sensitive drop happen linear from 4 to 5.5k rpm. Not step change, delay was in the dash gauge.

Reducing pressure drop across the plumbing is great but I bet I would just move the drop to a higher pressure. Like 65 psig to 59 psig.

Solution may be heavier weight oil or oil that doesn't shear as easy. Remember we are only talking 6 psig.



This emphasis the need for a builder like blykins who supplies a complete build Manual eliminating the guess work.

With oil warm, 60c, coolant at 80c pressure drop only 1 psig.

In the end I am a nut as three of my buddies I told to watch gauge didn't notice the drop, wtf!!

[Rick Parker]

Are you able (for testing) remove the oil cooler adapter entirely and use a filter about 4" long. Look at the filter construction and the threaded end of any filter being used, get the one with larger holes around the perimeter. Keep K&N brand in mind, they are well constructed.