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Marvel Mystery Oil

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Stache

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Feb 27, 2004
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For all practical purposes, 80 octane aviation gasoline is no longer available, forcing the Cub driver and other to choose between 100LL avgas and 87 octane automotive gasoline (assuming that he has the necessary STC and that "mogas" is sold at the airport). Each fuel has its own problem. Despite the low-lead designation, 100LL contains too much lead for the older, low-compression engines. Mogas, on the other hand, doesn't have enough: some lead is needed to lubricate the valves.

Many other aircraft owner are using Marvel Mystery Oil to reduce the buildup of lead from 100LL. Does any one have information or testing of this mystery oil in type certificated aircraft engines as an additive?

Stache
 
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I was doing some research on the Marvel Mystery Oil and find the web site which is a piper club forum. I also found AVBLEND web site. Since I work with aircraft owner many seem to believe Marvel Mystery Oil is approved to use in type certificated aircraft, which it is not.

Several aviation supply companies advertise the oil for sale and in at least once case it was the cause of an accident NTSB Identification: NYC02LA181. When added to aviation fuel it will turn fuel pink to red in color.

I was hoping someone has done some research on the oil as an additive and what happen at altitude and if it does cause detonation.

Stache
 
I work with several Cessna CE-195 owners that have round engines on their aircraft. Many mix Marvel Mystery Oil with their fuel to prevent deposits. This is contrary to any FAA approve date I know of. My original question is has any manufacture done any testing of this mystery oil in aircraft engines. After checking the Material Safety Data Sheet I cannot believe anyone would add it to fuel as a fuel booster or fuel system cleaner.

Stache
 
One more note, there is an enviromental movement to out law the manufacture of MM. It is already out lawed in Canada.
 
I used Marvel in my C-170, precisely to prevent valve problems from 100LL; which it took care nicely. I added about half a quart at each oil change and a capful or so when topping off the oil.

The airplane had a can under the rear seat when I bought it, and I ignored the hint. After having 2 stuck valves on a cross country and enough aggravation to get the engine sorted out, I started using Marvel and never had a hint of the problem again.
 
I haven't been back to the aero forums in a spell and , wow, Marvel the Mystery Oil, AGAIN!
We used it on our J-2, a couple of Cessna T-50's and, a Mac RCAT powered Benson---never had a problem of any sort that I recall. I even used it in the total loss lllubrication system of my Judson supercharged MG-TD.
Looking back some 50 odd years, I think we were victims of wishful thinking. Today I find that MMO is great for lubing pneumatic tools and water proofing my work boots!

Rod
 
Bear in mind that MMO may contain lead; I carefully tasted a tiny bit, and it was sweet. (Don't try this at home.)

Stay with the mfr recommendations.
 
The beneficial effect of the MM oil may be that it contaminates the 100LL lead deposits with elements that soften or otherwise allow the unwanted deposits to flake off or be pounded out of the Exhaust valve margin. This could enhance proper exhaust valve seating when using the 100LL. Operating engine cowls to achieve a minimum of 300F CHT is also recomended, I understand that this enhances the function of lead scavenging chemicals in the fuel.
 
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