RV7Factory

RV7Factory

Chief Obfuscation Officer
Aeromag Ponderings

I clicked over to Aeromag, one of Doug's new advertisers, and was reading some of their collateral when I had a thought...

I understand the concept and benefits of the Aeromag, but it appears to me that it potentially removes (not literally) contaminants that might give an indication, on an oil analysis, that something is going wrong. It seems like there is a bit of a trade-off between the benefits of the Aeromag and the benefits provided by the data from an oil analysis.

I suspect you are better off *knowing* that you are running cleaner oil, rather than having a greater *potential* to catch something through analysis, but it did seem to be a bit of a paradox to me. Am I missing something here? Any thoughts or comments?
 
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You really should be cutting the filter at each oil change in which case you should be able to visualize the stuff that the magnet picks up. Does it really affect the oil analysis? I have my doubts that it is strong enough to pick up things in solution on the order of ppm... ?

Thomas
-8 wings
 
Cute

kevinh said:
Here's what the car talk guys have to say on the subject:
Click to expand...
Love the car talk guys, couple of knuckle heads (smart witty knuckleheads). Like Click and Clack said, cute and can't hurt but probably will not help. It sounds like they where talking about the drain plug magnet and not an oil filter magnet. They also where shooting from the hip, as they often do, but they are probably right.

I would love someone to test the aeromag. Do oil analysis pre and post magnetics.

I talked to them when they came out well over a year ago. They where willing to send me one to try out. They also sounded genuinely interested in getting feed back and where not all hype. They wanted me to tell them what I thought. I was not ready to fly my plane at the time so I declined their offer. They backed it up with an open return if not happy. I say if you got a $100 burning a hole in your pocket buy one and test it out for the group.
 
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Don't forget the Finger Screen

I agree with Tom's statement entirely about cutting open your filter. The magnet will pick up particles, and it is perfectly normal to have some amounts of ferrous and non-ferrous metals (particles, not chunks) in the filter even in newly overhauled or new engines. We don't recommend oil analysis until 50 hours, and then every change after that (25 hours) to start tracking trends.

Do, however, check the finger screen at the rear of the sump at every oil change. The crush washers aren't expensive, although it can be a bit hard to reach. It is a critical component in the life of your engine. Finding flakes of metal in the screen will give you an indication that you might have bearing delam or other problems that need to be addressed before something serious happens in flight.

Good Luck.

Rhonda Barrett-Bewley
Barrett Precision Engines, Inc.
 
This from Theresa at Aeromag (emailed to me)....

"Of course trend data is important in analyzing the health of any engine. Upon your first use of the AeroMag on your oil filter, you will notice the following: Upon analysis of the oil you will have a new basis for comparison to all following tests.

In other words you begin with new data (which will be lower) this will be used to establish your new trend data. And important as the NEW comparison basis for follow on testing.

You will also notice that your soft metal counts will discrease - as the hard metal is trapped and held and therefore cannot generate as much soft metal to be sloshing around in your oil!

Getting the harmful steel particles out of the oil is the primary goal of the AeroMag Unit"
 
DeltaRomeo said:
In other words you begin with new data (which will be lower) this will be used to establish your new trend data. And important as the NEW comparison basis for follow on testing.
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Thanks Doug. I had thought this might be the case, but it is great to see the designer acknowledge this and explain its proper use. Thanks for posting, I can now sleep again. ;)
 
Filter Mag and AeroMag

Filter Mag and Aero Mag have the same appearance and come from the same address. Filter mag costs a lot less. I bought a RA365 for about $66 + tax compared to AeroMag at about $95 plus shipping from Spruce. The RA365 fits my Champion oil filter perfectly. Its instructions say not to use it on aircraft but they don't say why. One difference is that the AeroMag comes with a band clamp for additional safety. A loop of safetie wire would take care of that. I intend to use mine on my 180 hp experimental aircraft. AeroMag is trying for certification and we all know what that does to costs and thus prices. The RA365 is their "heavy duty" and "racing" model. The FilterMag brochure says 600 pounds of pulling force for my model whereas the AeroMag brochure says 750 pounds. FYI only.
 
As a geochemist, I hopefully can provide some information here. I agree that the magnet could/should pick up bits of ferrous metal and keep them from circulating in the engine and trashing other (particularly softer) metals.

I am not certain the details of how oil analyses are done, but typical water analyses are done on filtered water (very fine filter to remove essentially all non-dissolved materials). If oil analyses are done in a similar manner (perhaps someone can tell us whether this is the case or not), then there should be NO DIFFERENCE in the results whether you are using the magnet or not. That is, the magnet cannot pull dissolved metal out of the oil, it can only pull solid fragments out of the oil. Of course if your engine is thrashing around a lot of fragments of metal, then there is likely to be more wear and tear on the engine components, and perhaps higher dissolved metal content in the oil. This would clearly register in the analysis.

Alternatively, if the oil analysis is done on fluid that has not been run through a filter at the lab to clean out particulates (my guess is this is likely the case), then the analysis will reflect a combination of both dissolved metal plus particulate metal. If the magnet is doing its job as advertised, the overall metal content will probably drop by using the magnet. The amount of drop will be related to the amount of particulate (ferrous) metal in the oil.

If the analyses are done on unfiltered oil, then I might actually prefer to leave the magnet out of the system, unless you check it on a regular basis (i.e., when you change oil) and make notes on how much junk is attached. My reasoning is that if you have a problem that is generating scrap iron in your engine, the magnet may conceal this problem by removing that scrap from your system. Unless you are careful to examine the magnet (same as examining a cut open oil filter) and compare the relative amount of trash to the amount from the last oil change, you could miss this accumulation of metal, which means you could miss a signal that there is something going wrong in the engine. Without the magnet, that increase in metal SHOULD show up in an oil analysis (again, assuming they do not filter the oil before analysis so that the analysis includes both dissolved and particulate metal).

greg
 
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