Fuel Filter Used As An Oil Bypass Filter

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First of all I borrowed this from another site. It is not mine. It was such an unusual setup, I had to link to it. I looked at his UOA. He installed this filter at the 4K mark on his oil and ran it 2K more and sampled. He is using a CAT fuel filter head with a .070 output restrictor, and a Donaldson 2 micron Fuel Filter. Excellent UOA report on Delo 400 15W40. This is on a Ford PSD. Just amazing. My hat off to him and his work.
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The only thing is I would have reduced the output restrictor from .070 to .050 or .060 as a max. JMO


Fuel Filter Used as an Oil Bypass Filter

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To the owner of this setup.
 
Steve,

I honestly don't remember. I will try to find the post again. I was so surprised to see this work that I forgot to look.

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That looks so simple. I too have been thinking about a 2 Micron Fuel filter as a bypass but diden't know if it would hold up th the high heat of oil. Guess it does. DaveJ
 
The cost and frequency of changing such a filter may not be practical. may not have the depth nor volume to trap an OCI worth of particles.
 
For reference the FF oil filter on the right of the picture is a FL-1995 Motorcraft equivelant and is 8" long. And the Fuel filter on the left appears to be much longer. I would expect 6K plus miles on that filter before I would be concerned. But in honesty, I would do an oil analysis at 5K to see how the system is performing.

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very interesting. This may solve some space issues I have on my Jeep.

Is the difference between 2 microns that the fuel filter catches and the .05 microns that the TP filters catch really dignificant, from an engine wear standpoint?
 
Anybody check with the filter company to verify the micron rating?

Generally a fuel filter 2 micron filter is going to be nominal. That would be my guess, with absolute being toward 10 micron.

Plus as has been mentioned, fuel filter media generaly is not treated the same way as oil filter media because fuel filter media doesn't have to handle hot oil.

Basically there are less resins in fuel filter media.

However, one can "get away" with something like this.

Until there's a problem..
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The big problem with these filters is they have too much air and not enough filter media. Air is not very good at cleaning oil. I prefer a housing with a lot of submicronic filter media packed inside. A TP filter will filter 1/10th micron particles as easily as the pleated filters can filter 2 micron particles. Even a 1/10th micron filter can't filter all the soot particles. There is a huge difference between a 1/10 micron filter and a 2 micron filter when you are dealing with something like diesel soot. Why buy a 2 micron filter when you are dealing with something like diesel soot? Why buy a 2 micron filter when there are several submicronic filters available? The best are either TP or TP copies.
I have a filter on my diesel Ford that will probably filter better than TP but the elements are Scott Center pull paper towels. The housing takes two elements that make a 16" by 18" element with the quality of TP. It is orificed to filter at the same rate as the little TP filters. Size makes a difference. I had to find a big filter that could filter as good as the TP filters. TP has a lot of capacity but not enough for a heavy duty diesel. It takes someone like me to put a 750HP filter on a 165HP truck.

Ralph
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Yes, it makes a difference that the 2 micron filter will not filter as well as the a 0.1 micron TP filter. The rule of thumb is that contaminates are proportionally destructive as their weight. One gram of 5 micron contaminates is as destructive as one gram of 0.5 micron contaminates in your oil system. A few oil studies suggest ( suggest does not equal prove )that filtering to an absolute value of 3 microns roughly increases engine component life 150-200%. Getting into submicronic filtration increases engine life 200-300%. In general TP filtration is the best, centrifugal filtration the second best, and shredded-compacted cellulose or wound string the third best bypass filtration media.The drawback of TP media is that it catches sludge "globules" very efficiently, so it loads up relatively fast. These globules are thickened oil that forms around a contaminate particle.
 
Carock..
I find your rankings of by-pass filtration interesting.

Where did you find that information?

Considering Cummins, Caterpillar, Detroit Desiel and Mercedes have tested all types of by-pass filtration and have "recommended" the shredded newspaper/woodchip style as remote mount style...I was wondering who or how you think other styles are better..
 
I started with a Fram screw-on bypass and later changed to a TP filter. Blotter spot tests revealed that the Fram wasn't even close to removing the amount of solids that the TP did. What size those solids were, I can't tell you but you could see the ring on the paper clearly enough.
 
May I lend a bit of knowledge to all this? :) I work as the Associate Winemaker at Fenn Valley Vineyards, near Fennville. We "sterile" filter many of our wines going into the bottle. The Germans have done this for years as a matter of keeping wines with residual sugar from starting up again while in the bottle. We use a Clariflow 0.45 µ filter rating for this. At 0.45µ it is enough to stop ALL yeasts and many bacteria. 1 micron is .000039 inches in diameter and to give relative examples...

Diameter of average human hair 70 microns
Lower limit of visibility (naked eye) 40 microns
White blood cells 25 microns
Talcum powder 10 microns
Red blood cells 8 microns
Bacteria 2 microns
Carbon black 0.6 microns
Tobacco smoke 0.5 microns

So to be all fair, given the above statement about engine life, then anything in the 2 micron (bacteria) to 8 micron (red blood cell) should suffice to give the oil a clean enough condition to EXTREMELY lessen wear. Grant it, 0.5 would be nice, but let's look at practicality. The tighter it is the harder it is to push oil through, and the less volume will be going through. Also the "extra" bit of miles you could "possibly" get from polish filtering the oil, is it measurable to the engine in wear or lack of? I doubt it.

I'm 53 years old and it seems like there was something of a sort of bypass oil filter on cars and trucks back in the 50's?? Correction anyone?
Here is a link to one that is using toilet tissue for filter media. http://www.bypassfilter.com/faqs.htm
Seems like this is what they used back then. Cheap and effective.

When you filter you have 2 styles of filters. Depths filters and absolutes. We use 40cm X 40cm depths filters to prepare wine for bottling and to clean it up. Different grades of filter pads are used that have different "porosity" for the wine. A pad filter is a "DEPTH" filter, meaning it is like a beaver dam. The dam filters out large dead fish, and debris as long as the flow is not over done and consistent, same as a depth filter. Debris gets trapped onto the cellulose of the filter media and is held there until either back flushed out or disposed of. UNLESS you force fluid through a depth filter faster than what is 'nominal' for it and then the particles break apart and move on through the filter, thereby decreasing the overall effectiveness of the filter to begin with. Key is constant but not extreme pressure.

Absolute filters are a bit different. Imagine a ceramic tube with holes drilled in it. The hole is 1/4" in size and you have marbles going across it at 1/2 in size. They cannot pass through, no matter HOW high the pressure is, and are a lot more prone to plugging than the depth filter, such as the oil filters and toilet paper method. :D But, when you absolutely have to have tight tolerances for what you are filtering, they have a lot more latitude in flow than do the depth and do an excellent job for their life span.

The one thing I would see as to be beneficial to bypass filters would be dual pressure gages. One for oil on the inward side and one for oil on the outward side on pressure. Then you can look at the two gages and tell how much the filter is plugging or absolutely plugged by the differential pressure across the 2 gages.

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There are plenty of places (and people here) that can better source the specs and do the math than I, however I would like to add a few things. 2 microns is decent as a bypass oil filter, however I would like a high efficiency at 2 microns to consider it a good investment as a bypass filter. My second concern is really only in the above example given. The truck is a 2wd and the filter is hanging below one of the front I-beams with the truck stationary at ride height (I'm assuming they weren't driving down the road when the picture was taken and no frame hoist was employed allowing the suspension to fully unload). When the front suspension is compressed, that filter will be even lower to ground in relation to it's position to the I-beam when at ride height, albeit only slightly. This does not seem advisable from many aspects, imo.

Nebraskan, I agree that pressure gauges would be helpful for determining change intervals on the filters. On several trucks I work on I have put gauges on the output of the bypass. I just use the truck's oil PSI gauge for the inlet (not precise as the pressure will probably be slightly less at the bypass inlet depending on the plumbing method for the bypass and oil gauge). I would prefer to have a flow meter on the bypass outlet, however they are quite expensive for the intended application.
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Nebraskan..

Luberfiner by-pass filter came about in 1936.

So yes, cars before the 50's had them. Luberfiner offered a full range of by-pass housings from ones for 4 quart oil capacity engine to over the road heavy duty engines.
 
I have to take the word of the experts on sizes of different things. My experts say a human hair is about 90 microns. Carbon black is as small as .07, diesel fuel injector about 2 micron. Where you really get into tight clearances are things like piston rings, valve train and automatic transmission, valve body and control valves. These parts are down to 0.1 clearances. All I need to know about TP filters is that you can mix carbon black in oil and the TP will take it out enough to make the oil clear on the first pass. There will be a small amount of soot particles small enough to get thru even TP. That is why the oil in a gasoline engine will look better than the oil in a diesel even though lab analysis will show the soot level is very low. I have never claimed that TP is a fast filter. My best soot removing filter is what you would call large for automotive use. It holds about 4 gallons of oil and filters at the same rate as the little filters. To filter fuel you have to remove the orifice. There are several submicronic filters on the market. Your engine doesn't know the difference, but your budget will know the difference. When I started in 1963 the top two filters were the Frantz and Motor Guard. Things are back where they were now that that they are back. It depends on what design you like the best.
Submicronic big filters are rare these days. I am going to install a filter on a Mercedes engine in a new motor home. "Mr. don't drill any holes in the frame" retired U2 pilot. I've done two Powerstrokes and a Dodge Cummins for him. I think it is like a Fedex truck, a 5 cylinder diesel. I normally don't have time to install filters. He liked to take pictures of the installation.

Ralph
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