Full flow oil filtration

356 Porsche-related discussions and questions.
Post Reply
Message
Author
User avatar
Ron LaDow
356 Fan
Posts: 8092
Joined: Wed Mar 26, 2008 11:45 am
Location: San Francisco

Re: Full flow oil filtration

#76 Post by Ron LaDow »

Martin Benade wrote: Fri May 03, 2019 7:48 pm I have that setup and I think it is said to be unfiltered when the pressure relief valve is open, meaning full filtering almost always.
It's called "Priority Mains" in other engines. Here's an illustration:
oil system001.jpg
oil system001.jpg (333.16 KiB) Viewed 1683 times
On start-up, the oil pressure forces the vertical plunger down, allowing oil to hit the main galley almost instantly by flowing upwards through passage "C", but since it didn't pass the cooler, in your system, that amount is not filtered. Once pressure is established at the main galley, the oil flows through passage "B", adding pressure to the spring and closing off the pump feed to passage "C" and forcing oil to flow up though passage "A", through the cooler, to the bearings with excess pressure dumped via downward oil flow in passage "C", out the horizontal plunger-valve; very clever.
In the stock system, (keeping in mind Vic's comments regarding the output of the pump)this happens pretty much as soon as the pressure light goes out, meaning something like 99.9999% of the oil the bearing see is filtered. I have no idea whether the length of the hoses has any effect on the time required.
In order to avoid any change at all to the stock lube engineering, the Pre Mat parts break the flow immediately at the pump output and return it at the same place, filtering 100% of the oil:
616 Precision Matters Oil System Rev 3.jpg
616 Precision Matters Oil System Rev 3.jpg (3.14 MiB) Viewed 1683 times
Ron LaDow
www.precisionmatters.biz

User avatar
Gary Koehler
356 Fan
Posts: 374
Joined: Wed Apr 09, 2008 2:22 pm

Re: Full flow oil filtration

#77 Post by Gary Koehler »

Al Zim,
“... MOST IMPORTANT!! MR. GARY KOEHLER YOU SHOULD IMMEDIATELY REMOVE THE SCREWS THAT HOLD YOU SUMP PLATE ON AND PUT IN STUDS. IF A SCREW COMES OUR OR IS LOOSE ALL YOU WILL HAVE IS A SET OF SHEET METAL THE REST OF THE ENGINE WILL EXPLODE”

Al, you are correct but this is not how the sump plate is mounted in the engine - this was the plate taken off and immersed in the drained oil from a full flow filter system, about 3K miles on a well cared for mechanic’s engine. It was immersed for 24 hours this way; I put screws in to hold it together for that test only.

As you can see, the full flow filter does not remove anywhere near the suspended iron build up in the engine oil between changes.
Sorry about the confusion.

User avatar
Gary Koehler
356 Fan
Posts: 374
Joined: Wed Apr 09, 2008 2:22 pm

Re: Full flow oil filtration

#78 Post by Gary Koehler »

Al,
The photo shows iron buildup at of the magnet locations.
Attachments
51D13228-0F46-4EAA-A7CD-ABD7A8999F59.jpeg
51D13228-0F46-4EAA-A7CD-ABD7A8999F59.jpeg (2.1 MiB) Viewed 1628 times

User avatar
Al Zim
356 Fan
Posts: 4307
Joined: Thu Mar 27, 2008 12:37 pm
Location: FT.WORTH/DALLAS TEXAS
Contact:

Re: Full flow oil filtration

#79 Post by Al Zim »

Gary: I am confused why you removed the suds and installed screws? If you have material on the magnets I would be looking carefully to find where it came from. Am I missing something there also? Finally a comment about regarding keeping the original oil filter. I do not believe the heat dissipation from the filter will significantly reduce the oil temperature in the engine. There is always the opportunity for the lines to and from the filter to leak. al zim
www.allzim.com 
356 Parts and Services
www.facebook.com/ZimsAuto/
www.instagram.com/zims_autotechnik/

User avatar
Gary Koehler
356 Fan
Posts: 374
Joined: Wed Apr 09, 2008 2:22 pm

Re: Full flow oil filtration

#80 Post by Gary Koehler »

Al,
Perhaps you didn’t see the article in the Registry Magazine which goes into this in some detail. But basically this is a steel plate which slips over the studs on the engine case as before, on the backside of the plate is an array of very high strength magnets. So the entire plate surface (facing the oil) is magnetized by the magnets on the back using a technique called a flux concentrator, it is 10 times stronger than original, and the area is about 10 times larger, so that’s a factor of 100 increase in the magnetic field strength-area.The original ring magnet is discarded as it is fairly useless. The magnetic sump plate is meant to supplement a full flow filter; they both work together in a “belt and suspenders” relationship as the Brits say. What you are seeing on the plate are the metallic particles that have either made it through the full flow filter or from the return oil falling into the sump. The engine oil was drained after 3000 miles, I placed the magnetic sump plate in the oil for 24 hours. What you’re seeing is the suspended iron particles in the oil that were attracted to the plate. The screws were there only for this test.
Attachments
CE6B8751-D687-4F8F-AACF-B2CC146AC565.jpeg
CE6B8751-D687-4F8F-AACF-B2CC146AC565.jpeg (2.76 MiB) Viewed 1603 times

User avatar
Steve Hatfield
356 Fan
Posts: 1035
Joined: Wed Mar 26, 2008 8:54 am

Re: Full flow oil filtration

#81 Post by Steve Hatfield »

Gary
A minor correction: the Brits would say ‘belt and braces’ vice ‘belt and suspenders’.
Steve Hatfield
Fort Walton Beach, FL
'63 S90 Sunroof Coupe
'06 997S Coupe

User avatar
Gary Koehler
356 Fan
Posts: 374
Joined: Wed Apr 09, 2008 2:22 pm

Re: Full flow oil filtration

#82 Post by Gary Koehler »

Thanks Steve, sorry all

Dan Epperly
356 Fan
Posts: 1139
Joined: Thu Apr 01, 2010 4:35 pm

Re: Full flow oil filtration

#83 Post by Dan Epperly »

Curious. I full flowed my 912 which I just rebuilt the engine and gear box. I did the cam break in and have put about 10 miles on the car. Normally I change the oil right after breaking in the cam on VW engines that are not full flowed, then again after five hours of operation then at 500 miles then normal oil changes.
I'm thinking with the full flow set up that's overkill. What would be a reasonable oil change regimen on a rebuilt engine?

User avatar
Martin Benade
356 Fan
Posts: 12181
Joined: Wed Nov 23, 2011 10:52 am
Location: Cleveland, Ohio

Re: Full flow oil filtration

#84 Post by Martin Benade »

That probably is overkill, but it doesn't cost much to change it too many times. If it keeps you comfortable, do it.
Cleveland Ohio
62 Cabriolet
56 VW
02 IS 300
04 Sienna

User avatar
Ron LaDow
356 Fan
Posts: 8092
Joined: Wed Mar 26, 2008 11:45 am
Location: San Francisco

Re: Full flow oil filtration

#85 Post by Ron LaDow »

Dan Epperly wrote: Sat May 04, 2019 10:34 pm Curious. I full flowed my 912 which I just rebuilt the engine and gear box. I did the cam break in and have put about 10 miles on the car. Normally I change the oil right after breaking in the cam on VW engines that are not full flowed, then again after five hours of operation then at 500 miles then normal oil changes.
I'm thinking with the full flow set up that's overkill. What would be a reasonable oil change regimen on a rebuilt engine?
Any comparison between a non-filtered engine and an engine with full-flow filtration is apples and oranges.
If you have no access to a dyno, presume 50 miles is the dyno run-in (and do it with variable loads and throttle levels). Change oil and filter(s) and give it another (your choice) miles, change the oil and filter(s) again; the 'curve' of the crap pulled from the engine in general and the 'break-in' of the bearings is biased highly to the left. If in doubt, change it and them again.
But Gary's posts point out the impossibility of getting all of it out of the oil; that stuff is pernicious! Any web search of by-pass/full-flow filtration will tell you that the full-flow makes sure the bearings last far, far longer than no- or by-pass filtration but adding a fine-grained by-pass to a full-flow (like the one we have) picks out tiny bits from the small portion of oil it filters.
Gary, are you willing to put together a kit for those who are serious about that?
Ron LaDow
www.precisionmatters.biz

User avatar
Gary Koehler
356 Fan
Posts: 374
Joined: Wed Apr 09, 2008 2:22 pm

Re: Full flow oil filtration

#86 Post by Gary Koehler »

Ron,
Spent my entire career in high energy physics engineering R&D, never have been interested in production. Sounds like it might be right up your street, though; talk if you want

Right now I’m looking at a heretical idea that nobody in the “you gotta filter your oil” community would like – no filter at all...

User avatar
Martin Benade
356 Fan
Posts: 12181
Joined: Wed Nov 23, 2011 10:52 am
Location: Cleveland, Ohio

Re: Full flow oil filtration

#87 Post by Martin Benade »

Interesting idea. Maybe that would just about equal the factory filter in actual performance?
Cleveland Ohio
62 Cabriolet
56 VW
02 IS 300
04 Sienna

User avatar
Harlan Halsey
356 Fan
Posts: 2339
Joined: Fri Mar 02, 2012 2:05 pm
Location: No Cal SF Peninsula

Re: Full flow oil filtration

#88 Post by Harlan Halsey »

Which, as we know by now know, if you didn't know before, is 100,000+ mile life , not limited by bearing performance.

User avatar
Martin Benade
356 Fan
Posts: 12181
Joined: Wed Nov 23, 2011 10:52 am
Location: Cleveland, Ohio

Re: Full flow oil filtration

#89 Post by Martin Benade »

Yes, as the bearings require dirt and grit to function happily.
Cleveland Ohio
62 Cabriolet
56 VW
02 IS 300
04 Sienna

User avatar
Gary Koehler
356 Fan
Posts: 374
Joined: Wed Apr 09, 2008 2:22 pm

Re: Full flow oil filtration

#90 Post by Gary Koehler »

Martin,
“Interesting idea. Maybe that would just about equal the factory filter in actual performance?“
Martin,

Do the math. Look at the swept areas of the piston rings/cylinders, the cam, lifters, pushrods, rocker arm tips, shafts, and oil pump gears. It’s all generating iron in some form and it swamps all other particles by about 1000 to 1 or more.
In your engine there is an iron-based slurry mixed in the oil that’s grinding the crap out of everything that touches/contacts/rotates/slides against each mating surface, or momentarily does. What’s left? A tiny bit of aluminum, copper and brass which has nowhere near the abrasive and wear qualities that the iron does.
The filter, partial or full flow, does not resolve the issue as it reintroduces particles - iron is iron and if it’s in constant or momentary contact with mating/rubbing/sliding/rotating surfaces, it’s going to add to wear, generating yet even more iron. A vicious circle that tends to destroy an engine.

He who controls iron controls everything.

Post Reply