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MG MGB Technical - Oil filter magnets

Ok, normally if I see any sort of magnetic engine enhancing devices I am very, very skeptical. But I saw one in a car magazine that actually seemed to make some sense. Well, maybe. It was a collar thing that goes over your oil filter and it contains powerful magnets in it. They are supposed to trap any small pieces of metal floating about in the oil that are too small to be stopped by the filter. Now that makes sense to me that they would indeed trap metal particles. No mumbo, jumbo there. But would something like this actually help? Are they normally little bits of metal floating about in the oil not stopped by the filter? I figured that's what the oil is there to stop, metal to metal contact. Only thing I thought could be bad was if you get lots and lots of stuff held to the inside of the filter then it suddenly decides to move all at once so you get a big lump of metal bits though your engine.

I suppose I could do my own experiment with some rare earth magnets pulled from dead hard drives and duct tape (although really I think good oil and regular changes of it and the filter will do me just fine)!

Just wondering if anyone else has come across these.

Simon
Simon Jansen

I've seen them but didn't know ho well they worked. A magnetic drain plug allows you to see how much metal is being collected and you can remove it yourself. Anything large enough to matter shouldn't make it through the filter anyway.
Jeff Schlemmer

Hi Simon.

There is a fairly long thread about this in the archives.

My personal opinion is that your idea of the hard drive magnets strapped to the can is a good one as it might help a little and costs nothing.

I seem to remember that it was felt that it is a good idea to leave the magnets in place until the filter is off the car when filter change time comes along.

Don
Don

Simon, I had a Mini with the magnetic sump plaug referred to above and the amount oif metal collected was truly astounding or frightening depending on your viewpoint.

It may be oil circulating in a pressureised filter at a reasonable velocity is not able to be collected but when it settles in the sump gravity lends a hand.

Worth a try especially since it costs almost nothing apart from a time investment and may prove effective.... just don't fill up the Magnatech!

Cheers , Pete
Peter Thomas

Simon,

This is one of the latest ideas

http://www.machinedesign.com/ASP/viewSelectedArticle.asp?strArticleId=58726&strSite=MDSite&catId=0

Paul
Paul

I've never found a magnetic sump plug locally. I would have thought the local parts places like Supercheap and Repco would have them but I've not noticed them there. I think I'll try to get hold of one somewhere.
Simon Jansen

I bought a magnetic sump plug off ebay. The first oil change after a rebuild I had lots of magnetic bits. After that virtually none. I guess that is good news. If magnetic stuff shows up - you got problems.
Barry
Barry Parkinson

Why not make your own, we all have the small magnetic buttons in the office, drill the sump plug and using one of the better 2 component glues fasten the magnet in the hole you have just drilled, works a treat.
Clive Skelhorn

I used to have an MG 1100--it had a magnetic oil plug as well. Lots of metal on it--because the gearbox and engine shared the crankcase--like on the mini. It was there to collect any metal bits that were too large to flow into the filter. MGB's don't have an awful lot of machinery insde their engines that would wear off ferrous metal, mostly non-mag bearings. Magnets on a filter would only attach to particulate that was already trapped in the filter....if even then. If the filter housing's steel--it's going to seriously attenuate the magnetic field generated by any added on magnets. There are much better uses you could put your time and money than this.
R. L Carleen

Now if we could just find something that will attract all the non-magnetic particles like the bronze, carbon, aluminum and dirt that gets sucked in.
CDD Dewey

Paul, when can we expect to see that new oil filter for the B? That's pretty cool, if it really works!

Jeff Schlemmer

These magnetic devices are a great marketing idea. The idea does seem logical and to some degree a real benefit. However, as noted, the magnets trap only ferrous particles in the ‘dirty’ side of the filter housing, where they would be trapped anyway! One school of thought is also that by concentrating a large amount of material in one ‘high pressure’ and ‘High Flow’ area it can become dislodged by pressure pulses, but hopefully still retained by the filter element. (Except those with by-pass). So, absolutely no advantage whatsoever. In contrast, Magnetic sump plugs are effective in retaining the magnetic ‘sludge’, the ferrous bits being the ‘hardest’ and potentially most damaging to the engine. Magnetic sump plugs are used extensively in industry, aerospace and the automotive world, Magnetic filters are as yet un-proven and would need to be placed in an alternative location to the ‘standard’ filter. The cost of the magnetic parts would be very expensive to ‘build-in’ to the design, so the cost saving would be only of benefit to certain industries, where maintenance time is costly i.e. printing and process manufacturing. My suggestion…..change your oil often, it is cheep and you get to look at other stuff like points, plugs, leads etc at the same time!
MG Mike

Jeff,

I'm hoping a MGB owner who is also an Oil Consultant with NORIA can obtain one and carry out some testing.

The filter also collects nonferrous particles if ferrous ones are present in a process called heterocoagulation

Additional link
http://www.carchemistry.com/magnom.html

Paul

Paul

Attaching magnets to oil filters is an old timey mechanic's trick, going back to the days when oil filters were little more than steel wool stuffed into a can. Of how much value they are today is primarily a matter of how finely your filter can strain the oil passing through it. Of course, it could be argued that they have the potential of prolonging the service life of the filtration element by preventing metal from getting caught in it! One thing's for sure: they can't hurt, and can only help.
Steve S.

K&N oil filter. Problem solved.
Gary Kinslow '69B roadster Pale Primrose

Well working off the steel wool in a can idea. Why doesnt some brave soul get his steel wool magnetized and build a filter that way. Im sure you can get different gauges of steel wool etc to get the right filtration while allowing the right amount of flow. What do you think.
James

I think given regulation oil and filter changes the longevity of the engine is enough as it is. There are too many snake-oil merchants out there capturing the pounds/dollars of the unwary as well as those for whom the creed is "if it ain't broke we'll modify it".
Paul Hunt 2

This thread was discussed between 05/10/2005 and 14/10/2005

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This thread is from the archive. The Live MG MGB Technical BBS is active now.