Filter Mag for oil filter

I would imagine that if your engine was producing enough ferrous particles to cause piston wear then trapping them on a magnet would be the least of your worries. Ferrous particles would surely be less hard than the Nikasil cylinder linings in the 912 engines.

Given the worldwide population of 912 engines not using this without any great issues that may be evidence alone that it is not worthwhile.

I am always cautious of adding additional parts to my aicraft that are not specified by the engine/airframe manufacturer. There is always the risk of unintended consequences.

Food for thought,

I'm with Kevin. If you find any magnetic particles in a filter or on the magnetic plug you have a bigger problem and a magnet on our Rotax filter isn't necessary. Plus magnetic debris should be on your magnetic plug to indicate something's going on. I do lots of testing and research I rarely post. I just like knowing. So I wrote down what I found in 30 filters I pulled off a Rotax engines.

I check my filters this way. I of course cut the can open, then cut the fiber medium off the inner filter part. Here many just open the paper filter and look, but many things can be hidden here and small or fine metal dust can easily be overlooked. So I put my cut out filter medium in a glass pickle jar with 1" of gasoline. Put the top on and and gently agitate the jar like a washing machine. Then I pull the filter out of the jar and open it up and inspect it. It's always completely clean now after the fuel wash. Now here's the important part. I take a catch can and put a white paper hand towel over the opening. Then pour the residual gas in the jar over the paper towel. The gas strains through the towel, but any particle no matter how small stays on the towel and stands out like a red flag. If you saw anything then you could use a magnet and check it if you wanted.

But what I found with those 30 engines was "nothing" just an occasional spec of carbon or two. No metal. If you don't see something on the regular magnetic plug that you're supposed to check every oil change then you probably won't find anything in the filter. This said these were owners who use the proper oil and do the regular oil changes like Rotax suggest.

So I think a magnet put out on the oil filter won't help you. Just do the regular magnetic plug inspection.

For many years I attached strong magnets to the exterior of my vehicles' various oil filters (including aircraft engines).  Upon cutting open the oil filters I typically found a very fine, almost imperceptible haze associated with the magnet's location -- extremely fine metallic particles I suspect -- nothing in my opinion to be concerned with.  I concur with Kevin and Roger above.

Oil filter magnets are kind  of like the idea of copper wrist bracelets that used to be popular years ago.  If you think they work better than the existing filter element then you will love them, however it is a redundant addition to your engine.   The filter element does the same thing and one of the checks on a filter element in evaluation is to cut out the element and then squeeze out the oil in the mat.  After that on the outside of the mat run a small magnet over it to see if any ferris material is found.  

If the magnets make you feel better about the effectiveness of the filter element then sure, go ahead.  

Cheers

Thank very much for your answer.

Alejandro Zapata

Spain