marvel mystery oil controversy

[murpor]

Maybe this has been already discussed and somebody could direct me to the right place.
The fact is that as a pilot of small planes I have noticed that many owners of old planes like Aeroncas, Luscombes, Pipers, Cessnas, Porterfields, use regularly the additive Marvel Mystery Oil. These planes use the classic and proven Continental 4-cyl air cooled engines. I have even seen Cessna 310 (a twin engine 6-cyl. plane) using it. A guy down the street uses it on its old Harley-Davidson motorcycle.
And yet, a VW professional air-cooled engine rebuilder once told me never to put "that stuff" in my VW engine because it would destroy it.
Question: What is the feeling about Marvel Mystery Oil in the Porsche 912 community? Any positive or negative experiences?

Luis

[cgarr]

I use it in both of my planes and my 72 VW and always have with no problems. I also use the Aeroshell 80 straight mineral oil in all these engines SAE 40 and will use it in my 912 especially after rebuilding the engine next winter. Its a great breakin oil and will not foam up under high heat and RPM. I will never use any of those super slick oil products again, tried them in two C-85's and they both started using oil, for some reason it makes the rings stick to the pistons, had to re-ring both engins.

Oh a little in the fuel is always a nice thing to do for the top end too.

Craig G

[pjv911]

Marvel mystey oil is exactely the same thing as automatic trans fliud. Its a lightweight high detergent oil with red dye in it. Its a very good additive because it is a high detergent oil and keeps your engine clean and rings from getting carboned up. IM SURE THERE IS SOMETHING HERE ON THE WEB TO SUPPORT THIS.

Kurt Williams

P.S. It is NOT the same as type F with has friction modifiers. Dont use type F in you motor or gas !!!!!!!!!!

[murpor]

Interesting replies from Craig and Kurt. Now, how much should I use of Marvel Mystery Oil (or transmission fluid/ not type F)? Too little may have no effect. Hence a little bit more should be better. Even more should be even better. Now let me try the whole can which should quickly clean up the inside of the engine. The more I pour in, the better for the engine, right?
Luis

[WFBowen]

Marvel Mystery Oil seems to have attained religious status over the years & I'll admit to using it in the Palmer 4cyl. motor of an old Herschoff wooden ketch I restored. I did it only because the PO had used it for years, so why should I break the cycle - (sort of like a chain letter.)
On the more rational side, consider this: MMO came out in the early 1920's and was probably the first oil additive. Compare the motor oils of that time period to those available today - apples & oranges. But, if I were to rebuild a Palmer Marine engine, I'd probably pour some in just so I could sleep at night.

[murpor]

An extensive, interesting, informative, and critical paper about the oil additive industry and the effectiveness of additives, including Marvel Mystery Oil, appears in the following site: http://www.vtr.org/maintain/oil-additives.html

MMO, however, seems to do little harm in the long run, if used sparingly, I suppose.

Luis