Vintage BMW Motorcycle Owners

Seems every time there are photos of "slinger failure" it appears that the oil was sludge or missing.

What fills up the slingers, by centrifugal force, is the wear of the rings and cylinders.
If you put a magnet on the scraped out sludge, you will find that the magnet will pick put 100% of the sludge.

There are two things you can do, to slow this process WAY down.

The first is to have the cylinder walls silicone carbide impregnated after they are bored. This produces a cylinder that is as hard as nickelsil. The bore of a treated cylinder will last 150,000 miles with no wear. This means that all that is wearing away is the rings. You can simply change the rings at 50,000 miles and continue to run the engine.
eliminating the wear of the bore, cuts the amount of ferris metal suspended in the oil, and slows down the filling of the slingers. I had this done to all the cylinders of my personal machines, and most of the customers machines, if they agreed to the extra charges for having this done.

This is the company I used for many many years: https://www.millennium-tech.net/

The second important step, if you want to dramatically slow down the rate at which the slingers fill up, is to put POWERFUL rare earth, high temperature nickel plated magnet in the pan. This will magnetize the entire steel oil pan, and the nasty stuff will be pulled out of suspension, and stick to the magnet and the pan.

Even if you are not ready or willing to go to the extra expense of having the cylinders wall impregnated, DO put powerful magnets in the pan. And no, that little drain plug magnet is NOT enough!

As I said, while these two steps will dramatically slow down the rate, it won't entirely stop it. But, I have pulled an engine down that had 50,000 put on it after this was done, only to discover a very slight amount of deposits in the slingers.

Vech, Once again thanks for sharing your tribal knowledge. I have not heard of the cylinder treatment before. Have you got a source for the special magnets ? I will definitely do both of those.

I took apart 2 loudspeakers and attached their internal magnets to the oil pan.
I change the oil once a year, usually before summer and then I inspect the internal and renew the gasket.
I am doing the same with my BSA M20 (that has a dry sump).

This is where I bought POWERFUL nickel plated rare earth magnets.

https://www.kjmagnetics.com/

Vech
What part # do you use
Tnx
Tommy

I was wondering the same thing. I went to there site and ordered part number BYOXO2SH. 2"x1"x1/8"

Hi im interested in the idea of fitting rare earth magnets to attract the metal pieces , my question is ..if the whole sump pan becomes magnetised could I just not let it fix itself to the outside of the pan [a large enough magnet will not fall off and yet the pan will still be magnetised? Is that ok?

To answer everyone's questions
You want to use only the high temp magnets. The oil temp will kill the strength of a magnet not designed for high temps.

You want to put them inside the pan. That will expose ALL the sides to the oil. Yes you would put them on the outside, and no, they will NOT fall off. But you need to pull the pan, every 10,000 miles and clean the pan and the magnet(s) off. You will find them to be quite "hairy" with metal. You can place one in the pan, and you can place another on top of the steel pickup screen, and it will grab any metal flowing to the pump, and stick it in the inside of the pickup. If you do this, obviously, when you pull the pan to clean them, you will have to pull the the pick up screen, temporarily remove the magnet from it, and the use spray carb cleaner to wash out the metal particles from the inside of the pick up.

This is the one I would recommend that you use, it is suitable for high tempatures:
As just a fun fact, (I have these in all my bikes) I once returned from a ride, and noticed a steel wood screw stuck to the outside of the pan! The front tire kicked it up off the pavement, and it stuck to the pan...

What would be the best way to attach the magnets if an aluminum oil pan is used?