SS mesh filter conversation

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Since these types of filters are not popular but come up in posts once in awhile I figured I'd get some info straight from a manufacturer. I emailed Dave Fisher at K&P Engineering, who makes the filters sold by Scotts for motorcycles, asking about beta ratios and how their SS mesh filters stack up to a paper filter. I also asked about cleaning the filter and the idea that tossing in a fresh "clean" paper filter eliminates the posibility of reusing a contaminated filter from improper cleaning technique. This is a portion of the response from two emails: (I have Dave's permission to post them) The only way to compare the filter media directly to each other is to run them through the same test at the same time. I haven’t found anybody who could explain to me how you can scientifically use two different beta ratios to compare media, even though it is commonly done. Basically, throwing out a number at some percentage of efficiency just sounds good from a marketing perspective. Actual media performance is much more complicated. And there are plenty of white papers out there on the different theories. On top of it all you’ve got the media’s consistency factor as well as bypass operation and bleed by helping to complicate the subject. In order to compare the baseline filtration of filter media we use the ASTM test which eliminates percentages, averages, multiple passes, and all the other variables the SAE tests allow you to introduce. From the side by side lab tests we have had done, we meet or exceed the filtration performance of the factory filters. You may or may not want to take our word for it, after all we are a manufacturer and this could all be marketing jargon. When we run filters through the ASTM test, the paper filters (even the ones with 10 microns on the box) will actually pass particles ranging from 45 to 90 microns. The stainless cloth we use doesn’t pass anything larger than 35 microns (it actually tested at 17 microns). So yes, we meet or exceed the filtration of the factory filters as well as other (aftermarket) replacements. We feel the real benefits of the filter are in the increased flow of the filter media, reusability, ease of inspection and reduced environmental impacts. Remember that the stainless steel filter flows many times more than a new paper filter, so even if the ss filter is 50% plugged with debris, it will still flow around twice as much oil as a new factory filter. It is nice to believe that a new, fresh paper element will give you the best starting point for cleaning your oil. However, think about the cellulose particles that may not be totally attached to the paper mat (either in glued or pressed construction). Not a problem with our ss filter. Think about any dust and dirt that may have gotten into the filter during manufacturing, packaging, shipping, customers fondling the product on the dealers shelf, etc.. At least with ours, you can clean it prior to use to make sure it isn’t introducing any of that material into your engine (like you would with any other critical engine component). To substantiate that train of thought, one of the OEM motorcycle engineers just informed me that he has been finding that the small oil passages that feed the cam bearings are getting plugged with material off the paper oil filters. It comes back around to the consistency discussion. The simplest cleaning, and the one I like the best for the average consumer, is brake cleaner or carb cleaner, sprayed first inside out through the screen and then around the outside to wash the debris off. A soft bristle brush (like a toothbrush) can be used to dislodge stubborn debris if needed. If you want to go the extra mile, flush with soap and hot water. If compressed air is available, use it to blow from the inside out and then around the outside. Otherwise air drying works fine. If the particle is too large to get through the filter cloth, normal cleaning won’t “push” it through. The weave of our stainless steel wires keeps the openings pretty stable. If you believe that some dirt got washed into the inside of the element, just flush it out real well. The element, bypass valve and epoxy grooves are designed to make it as easy as possible to clean the inside of the element (when you look into the element you can see the entire inside of the bypass valve as well). The other thing to watch for is that we have had a couple of look alike filters show up out there in the reusable arena. We are flattered that they like our product and want to imitate it, but we have tested several of them and they have performed worse than the worst paper filters we have tested. They even use our copyrighted material to promote their product so make sure you get a genuine K&P Engineering manufactured product to ensure the quality. All of our filters have packaging that identify them as a K&P Engineering manufactured product. I’d just like to note that we think it is great when people want to get more educated on oil filtration. Many people don’t pay much attention to the subject. They look for the cheapest filter to throw on their engine thinking they all perform the same. I appreciated the candid response and it wasn't overly "sales pitch" and thought it was worth sharing.
 

Ndx

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Dave sounds like a really smart guy :) +1 for K&P if they just had application for my Mazda 3 2.3L I would buy that filter ...
 
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 Originally Posted By: tom slick
This is a portion of the response from two emails: (I have Dave's permission to post them) The only way to compare the filter media directly to each other is to run them through the same test at the same time. I haven’t found anybody who could explain to me how you can scientifically use two different beta ratios to compare media, even though it is commonly done. Basically, throwing out a number at some percentage of efficiency just sounds good from a marketing perspective. Actual media performance is much more complicated.
I don't think it's that much more complicated. The Beta Ratio is basically an effiecency of the filter to filter out a certain percentage of specific sized particicals. I'd think that the SS mesh screen filter would show a more uniform/stable beta performance because the media is built more uniform than fiber media.
 
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TOM - thanks for doing this.
 Quote:
It is nice to believe that a new, fresh paper element will give you the best starting point for cleaning your oil. However, think about the cellulose particles that may not be totally attached to the paper mat (either in glued or pressed construction).
So he compared to a poorly constructed or a defective filter? Doesn't seem fair.
 
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He put forth a good demonstration/argument there. I would see the sense to these things if they were either cheaper or if they had an exchange program. The cost is just too high (speaking generically about mesh filters). You'll never recoup your costs and probably not own the current fitted car for that length of time, nor will its replacement likely be able to use the same filter. Otherwise, I might use one and add a bypass filter (@ another $75-150)
 

tom slick

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They certainly are expensive for most applications. For my dirtbike the filter was $40 (it's just a cartridge), factory filters are $8 each and my dealer is not good at having them in stock. When I was riding a lot this filter paid for itself in 2-3 months and I don't have supply issues. Now if I could only find reuseable oil??
 
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An interesting read. That comment about paper filters passing particles 45-90 microns is a BIG comment though! Are there any further tests on this? It's definately a big thing to just say "90 micron particles get through your standard oil filter", but what's the real deal?
 
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If you look at particle counts (as flawed as they may be), you'll see some bigger particles in very small numbers. 50um would not be abnormal ..but again in small numbers (like 1-3). So, it's kinda a play on words where they don't give you the magnitude of relevance. Sorta like Castrol's "90% of all engine wear occurs at start up!!" ..while leaving off the part about that start up is about the first 20 minutes of operation ..and that most of the wear during that time is unavoidable.
 
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Ya. I read this twice and I think he did a lot of talking but cleverly avoided answering the question directly--did I miss something?
 
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Originally Posted By: Gary Allan
If you look at particle counts (as flawed as they may be), you'll see some bigger particles in very small numbers. 50um would not be abnormal ..but again in small numbers (like 1-3).
Ahhh, gotcha. So, at the end of the day, we still don't really know about the filtering qualities compared to paper then, do we? So... Paper filters - May let a very few particles of 45-90 micron size through, but will filter 'lots' of particles of, say, 15-20 microns. The Steel mesh filter - Won't let any particles bigger than 35 microns through, but will filter 'less' particles of 15-20 microns. so paper has less small particles, but few large particles. Steel mesh has more small particles, but no large (>35 microns) particles. ??? Something like that ???
 
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It would make sense that a mesh will be more uniform ..but I'm sure there's limits in sensible costs for a durable product in terms of how fine you can make it. You'll eventually have the same issues as you would with cellulose media. I think that there's probably much less wasted space in the mesh media ..but that's just my reasoning. It would be interesting to see what a pore blockage particle count shows with one of these filters. It's a modeled process, but it should still show a cutoff in particles.
 
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Depth filters offer a bit of redundancy around the multiple impact phenomena and can keep the large particles embedded- though this will result in lower flow rates upon saturation at least the culprit is jailed for a while. When flow rates are high in agglomeration processes many times a rigid mesh will cause fracture of large surface particles. Essentially the particles break off in varying aspect ratios until they pass through the media (think of making French fries). Certainly their dimensions are not uniform. Sludge, soot and other wear debris are a large geometric departure from standardized micro-spheres and offer differing paths of motion in turbulent and/or laminar flow conditions.
 
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The presence of larger particles in a particle count does not mean the filter passed them. The sample is usually collected from the sump. That is unfiltered oil. Ed
 
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It's filtered oil. It's perpetually filtered. That's why I found it such a non-statement when that original filter study guy obsessed on nitrile ADBV allowing "dirty oil to leak back to the sump" ..which was exactly where it came from ..in the same condition it was in. The difference between one pass and another "in process" would be essentially identical. Now bypass filtration will probably result in some accumulation of larger then spec particles just due to (assuming 10%) the average of refiltering 10% of the same oil. There you're into particle size "management".
 
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Not totally filtered. The oil that left the filter, lubricated the engine, and returned to the sump contains any particles that were generated or picked up on that pass through the engine. Ed
 
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Sure. Do you think that they would produce, outside of random chance, any difference in particle count? That is, out of 100 tests, how many do you think will be outside of some minor deviation from the mean? I'd say if you threw out any oddballs, you would still be left with the lion's share of the 100 tests being nearly identical. We're walking into that creative argument mine field again. grin
 
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Single pass filtration through a screen type media can allow for larger particles to pass through depending on their aspect rations. This happens at a lower frequency due to probabilistic impact models and fracture, but when one looks at a depth filter model of similar hole size (i.e. a web of filtration) the probability for pass through decreases. I've had to model this phenomena with food and pharmaceutical ingredients with similar characteristic rheology in a past life all and all it comes down to risk versus flow/efficiency. If you aren't worried about flow aspects you can take a calculated risk.
 
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Not creative, scientific. I can't help it Gary. It's what I do. I'm a research scientist. They pay me good money to look at data acquisition methodology and insure that all variables are accounted for and subsequently a control for that variable incorporated into the data collection. Cheers2 Ed
 
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