Although the pilot and FAA inspector did not report the same fuel tank as containing the red colored fuel, both were in agreement that the one tank contained the red colored fuel.

The operator told the FAA inspector that the red color was from an additive placed in the fuel tank, at a rate of one quart for each refueling. Examination of the engine revealed low compression on all cylinders, ranging from 44/80 to 5/80. Air bypass was noted on all exhaust valves, and on two of the intake valves. The number two cylinder was removed, and evidence consistent with detonation was found on the surface of the piston, and on the valves.

According to the FAA inspector, the additive that was added to the fuel was Marvel Mystery Oil. An empty 1 gallon can of Marvel Mystery Oil was found in the operator's trash. Instructions found on the can stated that the correct ratio for mixing with fuel was 1 part additive to 100 parts fuel. The contents of Marvel Mystery Oil were 74 percent mineral oil, 25 percent stoddard solvent, and 1 percent lard.

Ol Ford Guy (10/14/2008)

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Hey Rick,



You must be a Hallicrafters man. I wonder how many Y-Block guy's are hams? Our web site host is and so am I.



de W9PJ

HT32BSX115 (10/14/2008)

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This is one of those "Old Wives Tails" where some think MMO does something.......well.....because it's a "mystery"!



My dad used it and thought it did something because.......well, "I used it for 30 years and never had a problem"



I don't know why some think that an oil based liquid poured into gasoline helps the engine but there's a lot of people doing it.



I have owned a 1947 Stinson for 27 years that has a Franklin engine in it and have heard from many Stinson owners that MMO is akin to "Magic" stuff!! (I have NEVER put MMO in the oil or gas.....EVER......and NEVER will!)



Fact is, it's just a light mineral oil mixed with a (Stoddard) solvent.



I don't want to step on anyone's toes but it's pretty risky to put it in any FAA certified engine and then admit to running it because the FAA WILL absolutely take action against ANYONE who they catch using it in fuel intentionally.



I found this in an NTSB report: http://www.ntsb.gov/ntsb/brief2.asp?ev_id=20020916X01610&ntsbno=NYC02LA181&akey=1







In a high compression air-cooled aircraft engine detonation is more prevalent at high cyl head temps and low octane. ANY mineral oils added to high octane fuel will lower the octane......That includes solvents, diesel fuel, and kerosene. (This is a VERY common occurrence when a piston engine aircraft is mistakenly fueled with jet fuel......the engine fails due to SEVERE detonation as the kerosene hits the combustion chamber in higher concentrations usually during take off.)



Liquid cooled engines are less susceptible detonation because the combustion chamber temps are lower.







Snake oils like MMO and others are great for the people who sell them....I am skeptical of their benefits to people who use them.





Regards,

Our mechanic never put it in the fuel. He put it in the oil. He's one of the highest regarded helicopter mechanics in the southeast. In 40 years he's never had any problem with the FAA.

HT32BSX115 (10/21/2008)

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I would bet that he never told anyone at the FAA he did that. If he did they would probably suspend his license.



MMO is not an FAA approved additive for any fuel or oil for anything aviation. The FAA takes a very dim view of doing ANYTHING that is not approved and they usually take certificate action if they find out about it....

Well I don't know, I just fly 'em, I don't work on 'em .. I just know he did it and I flew it and I never had a problem.

HT32BSX115 (10/22/2008)

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That's very common. The difficulty comes from when a "problem" actually does happen. When the FAA discovers that the PIC "knows" of a discrepancy, yet continues to operate the aircraft, They can take action against the mechanic for using an "un-approved" device, fuel, oil, additive, etc which makes the aircraft un-airworthy, and then take action against the Pilot In Command for operating an aircraft in an "un-airworthy" condition.



It happens in the airline industry all the time. Mechanic makes a mistake in the maintenance logbook that renders the aircraft un-airworthy, and they hammer the mechanic and the pilot crew that subsequently flys the aircraft.





We have of course, sort of gotten off the original argument of whether MMO is "ok" for our Y-blocks I guess.....



To answer the original question. There's no actual evidence that MMO does anything except make the user feel good about his engine. .......(oh.....it increases profits for those who sell it!!)



There's a LOT of testimonial "evidence" that it doesn't "hurt" anything. [ My brother, uncle, dad, grandpa, Pet mechanic, friend, wife, husband etc etc etc used MMO, Slick-50, STP, and other "SNAKE-OILS" for many years and "They had no problems"]



Those reasons are not good enough for me.



I'll just keep using a good oil, and fuel. and do normal maintenance and drive my "Y" for many years.



I am worried about flat tappet camshaft wear. There's lots of industry info on that from camshaft grinders and manufacturers. I will follow their published advice.



Regards,





Rick