Carlostrece
$100 Site Donor 2025
This was an accidental post. Please disregard.
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I got my pair of Filter Magnets installed today.
- Thread starter Carlostrece
- Start date
This raises an interesting comparison. Bypass v. Magnet.
Magnet should catch undissolved ferrous debris of a certain size range (?u) and above that comes near enough to the magnet.
A bypass filter should catch ALL debris, 2-3um and larger IF the lubricant passes through the filter. Again, does this make sense for the average passenger car owned 6-8 years? Probably not.
Magnets are cool and great and - yes I am opposed to some lousy magnet that loses flux at 250°F stuck in a filter center tube and may heaven forbid move (yes these are sold!), or a weak magnet on the outside of a steel can (yes these are sold as well) - but otherwise yes, I like GOOD magnets! Especially in a new engine.
Magnet should catch undissolved ferrous debris of a certain size range (?u) and above that comes near enough to the magnet.
A bypass filter should catch ALL debris, 2-3um and larger IF the lubricant passes through the filter. Again, does this make sense for the average passenger car owned 6-8 years? Probably not.
Magnets are cool and great and - yes I am opposed to some lousy magnet that loses flux at 250°F stuck in a filter center tube and may heaven forbid move (yes these are sold!), or a weak magnet on the outside of a steel can (yes these are sold as well) - but otherwise yes, I like GOOD magnets! Especially in a new engine.
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Carlostrece
$100 Site Donor 2025
I agree that bypass filters are the best, if you can afford it and justify the expense. My 2 Filtermag only cost me $112 with free shipping. I didn't want to spend more.
If ignore the higher cost, then I agree with your valid points about why bypass filtration is the best.
However, Filtermag (or other good magnets) are much lower cost and I think they provide some benefits.
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My only question is about "undissolved" ferrous debris. Does the rest actually "dissolve" in the oil?
Just razzin' ya Pablo. 
Kinda sorta, as in the the particles small enough for most equipment used for UOAs to detect. How much is actually in classical solution, tiny.My only question is about "undissolved" ferrous debris. Does the rest actually "dissolve" in the oil?
All that ferrous wear debris is suspended in the oil as it's worn off the moving parts. I don't think any of it dissolves (as in the technical meaning) in the oil and becomes smaller. I'd say most of it is 5u and smaller, so that should be detectable in a standard Blackstone type UOA. There certainly could also be some of that ferrous debris between 5u and 20u. Most of the ferrous debris a magnet catches is the stuff the filters can't catch well ... especially if the filter is lower efficiency.
Agree.
Why I hedged, is chelation. Some Fe, Cu, other metals can be chelated by a few select additives and even some esters. Technically these atoms/ions would be in the (oil) solution. There has been recent discussion on this regarding relatively higher Cu in a UOA. Full circle to what is detected in UOA's, how a UOA could have low metal PPM yet metal caught in the filter (very worrisome), or a UOA could have an elevated metal, nothing of significance caught by even the best filter (somewhat less worrisome).
And back to magnets, these could serve not only as Fe wear metal catchers as well as diagnostic tools.
