Author Topic: What the heck is going on in the oil pan?  (Read 10677 times)

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Barry_R

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Re: What the heck is going on in the oil pan?
« Reply #30 on: August 06, 2021, 02:44:21 PM »
The reason for investigation lies in the confluence of Jay's and Mr Conley's observations.  Right now the bearings look fine.  What we don't know is whether they are perfectly OK or whether the system is right on the ragged edge of failure.  We don't know if we are at 99% of capability or 65% and we have no practical way to find out.  Since Doug is a bit of an audio guy, look at it as the mechanical version of dynamic headroom in a sound system.  A safety factor.  As Conley noted - Ford themselves had a system that crossed that line and it caused a lot of problems even in a comparatively mild application.  The system "as-is" is visibly compromised (or at least non-optimal) - so if it can be improved at a modest cost it makes plenty of sense to address the observed issue now and increase the safety factor - - and maybe even find a couple horsepower while doing it.

Cyclone03

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Re: What the heck is going on in the oil pan?
« Reply #31 on: August 06, 2021, 03:25:09 PM »
Maybe the Great FE Oil Pan and Windage Tray Comparo is in order... ;D

This is a great idea , go ahead and task the Great FE Comparo R&D team this project.

We’re waiting…LOL
Lance H

WConley

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Re: What the heck is going on in the oil pan?
« Reply #32 on: August 06, 2021, 05:13:04 PM »
The reason for investigation lies in the confluence of Jay's and Mr Conley's observations.  ...

Barry - Did you have a root canal today?  You're starting to sound like me or Scott (pbf777)  ;D
A careful study of failure will yield the ingredients for success.

frnkeore

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Re: What the heck is going on in the oil pan?
« Reply #33 on: August 06, 2021, 05:41:24 PM »
Regarding pressure drop, it could well be the aerated oil causing the pressure drop, fluid can't be compressed but, air can so, you could loose oil pressure with aerated oil and air doesn't lubricate very well, either.

My own little story on my pictured car. I had to pull the engine to replace a clutch and when I put it back in, there must have been a piece of something in the AN flare, on the intake side of the pump. I noticed a small drop in oil pressure, maybe 5lb (80 psi was normal). After 2 practice sessions, it had dropped more, maybe 12-15 total. I went all through the fittings and when I tighten one of them (a union) the pressure went up a little but, not to the full 80. With the external pressure adjustment I raised it to about 70+. I thought to myself, that will be ok. About 10 minutes in the race the engine, a rod bearing seized and put a hole in the block, about 10" behind me. Lesson learned!

Air and oil don't mix, so to speak! One compresses and one don't.

Frank

machoneman

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Re: What the heck is going on in the oil pan?
« Reply #34 on: August 06, 2021, 06:45:08 PM »
Well, for an oil pan comparo, here's Moroso's all-clear oil pan they use for testing. Given the FE's similar crankcase design, making one like this may not be that hard.

https://www.chevyhardcore.com/news/moroso-oil-pan-testing/
Bob Maag

Tommy-T

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Re: What the heck is going on in the oil pan?
« Reply #35 on: August 06, 2021, 08:23:47 PM »
Just curious.
Would plumbing a large stacked plate oil cooler into the system "de-aerate" or at least reduce the amount of air-infused oil that's cycled back into the engine?

Amazing how the oil "de-airs" itself with or without the vacuum pump.

One of things I never think about. I usually put a "blue" spring in a high volume pump, put the largest sump in the particular chassis I'm building for, 'n go. But I ain't making 800...or even 700 horses.

Thanks for the school'n.


Barry_R

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Re: What the heck is going on in the oil pan?
« Reply #36 on: August 06, 2021, 09:31:29 PM »
One other thing to consider is that most aftermarket oil pickups tend to be rectangular with perforated metal or a screen welded in.  Most every OEM pickup I can recall is more of a bell or funnel shaped with a much, much larger inlet area and screen surface.  Wonder if there is something there...

MeanGene

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Re: What the heck is going on in the oil pan?
« Reply #37 on: August 07, 2021, 09:25:12 AM »
One other thing to consider is that most aftermarket oil pickups tend to be rectangular with perforated metal or a screen welded in.  Most every OEM pickup I can recall is more of a bell or funnel shaped with a much, much larger inlet area and screen surface.  Wonder if there is something there...
The large bell shape has much more surface area, many times larger than the pickup tube itself, so the screen would have to be very clogged to inhibit flow. Might be something of a whirlpool or vortex effect? The aftermarket pickups seem like they would be cheaper to make.
There used to be a guy here in the 70's that ran a Super Stock roundy-rounder at Petaluma in the mid-late 70-'s, had a 67 Mustang running 427 LRs and did pretty well. He ran a very simple homebuilt dry sump setup, pan widened on the right, and used a HV pump to scavenge to the "tank", and a simple single stage Weaver pump for pressure. The HV pump was able to easily keep up with scavenging. A large remote truck "oil filter" held 8 quarts, because of course dry sumps were not allowed

6569fe

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Re: What the heck is going on in the oil pan?
« Reply #38 on: August 07, 2021, 10:52:46 AM »
Pump is getting aerated oil. Screen or Perforated metal pickup it is only going to supplying what it can get.

Joe-JDC

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Re: What the heck is going on in the oil pan?
« Reply #39 on: August 07, 2021, 11:49:48 AM »
When the oil pressure stalls, or drops, the pump has reached its limit to draw in more oil.  It would be interesting to know what your rod side clearances are.  I agree with some of the other comments that the square/rectangular oil screen is not sufficient surface area to supply non aerated oil, and your pick-up tube might be too small in diameter or have weld slag causing some turbulence.  Did you smooth the entry into the oil pump, block entry point, oil filter adapter, oil pump housing under the gears?  Also, you may be bypassing too much oil causing the aeration.  Just random thoughts.  Joe-JDC
Joe-JDC '70GT-500

jayb

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Re: What the heck is going on in the oil pan?
« Reply #40 on: August 07, 2021, 03:16:39 PM »
Joe, if I recall correctly rod side clearances were around .008" to .010".  All the oil modifications you mentioned have been done to the block.  Also, no welding on the pickup tube, it was just heated up and bent down somewhat.  I'm pretty convinced at this point that aeration of the oil is what is causing the oil pressure to drop, although I'm not sure why with the vacuum pump disconnected the aeration of the oil looks about the same, yet the oil pressure stays stable throughout the pull.  I may run that video test again, to try to get a better video without all the glare...
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

427John

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Re: What the heck is going on in the oil pan?
« Reply #41 on: August 07, 2021, 10:29:39 PM »
Are the rpm levels at the onset of the aeration and drop in oil pressure comparable with Bills observations on his test rig?Does this appear to be due to the same causes as what Bill saw with the HV pump in bypass or does it seem to be more related to windage from the rotating assembly?A close comparison of Bill's data with your own observations may make your decision on whether or not to try a std.volume pump a little easier.
« Last Edit: August 07, 2021, 10:35:27 PM by 427John »

Cyclone03

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Re: What the heck is going on in the oil pan?
« Reply #42 on: August 08, 2021, 01:33:23 AM »
The oil pressure by pass talk reminded me of an oil system discussion I had with a BOSS 302  road racer I know. In the days before drysump systems were allowed in trans am racing Ford tried many ideas and pump/pick up ideas to make the engines live. Many early ideas of course came from the Gt40 program and NASCAR as well. One idea that my friends group tried with the BOSS engines was to separate the bypass from the pump,like was done with the side oiler moving the bypass to the back of the block.
One solution I found interesting was to plumb a regulator at the rear  main oil gallery above #5 main bearing with the bypass oil line entering the pan on the rear left. Did it work? For a wet sump they felt the pressure was a bit more constant and the bearings looked better but it wasn’t so much better that it changed their inspection routine. The oil temp was down a bit though so they kept the set up with a change. They moved the regulator to the external line coming after the oil cooler,again with the return entering the oil pan on the left side.
Lance H

Gregwill16

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Re: What the heck is going on in the oil pan?
« Reply #43 on: August 08, 2021, 07:55:36 AM »
It would be interesting to see what difference it would make using a factory windage tray combined with a std volume pump with a C8AX style pickup.

KMcCullah

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Re: What the heck is going on in the oil pan?
« Reply #44 on: August 08, 2021, 10:12:35 AM »
Fascinating tests, Jay! If your bearings aren't showing any signs of distress after being fed with aired up oil, then I'd thing your clearances and oil supply are sufficient. For what it's worth, I think my 504 has the same crank as this dyno mule and has been spun past 7k hundreds of times. The oil filters were showing metal when I pulled it down last year for inspection. The rod bearings had some ugliness. The crank looked great. When I built it, I used the old rule of .001 per inch of journal diameter to established clearance. So .0022-.0025 was the range of clearance on my rod journal bearings. About the same side clearances as this mule, .007-.010. I added .0005 clearance to the rod bearings when I put it back together. This dropped the oil pressure to 60psi (was 70psi) at 7k rpms (now I'm breaking the old rule of 10psi/1k rpm :)) and almost zero psi at idle with a M57HV pump. But no metal in the filter. I wonder if aired up oil was my problem? Was running 15-40 Rotella. And I'm certain the oil was not getting up to it's designed operating temp. Have since switched to 10-30 Royal Purple.

My David Brown tractor has a oil bath style air cleaner. It has a series of screens stacked in the can body that the air is drawn through. I wonder if a stack of these type of screens at the top of the pans sump would help separate the air from the oil? 
Kevin McCullah