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StewartB
I'd like to hear some reasons why someone would put MMO into engine oil. I do, and always have put it into my fuel.
SB
SB
FlipFlop
Registered User
Maintaining at Flight Level Zero, requesting lower
stewartb said:
Because it's there...
Seriously, one reason is to clean out the creeping crud (especially carbon) that has accumulated inside the engine... MMO has a solvent in it that will free stuck rings amongst other things...
FlipFlop
Registered User
Maintaining at Flight Level Zero, requesting lower
cubdrvr said:
No Dave, Plus contains what we used to call "Buzzard Piss", the Lycoming snake oil that you had to put in the O-320-H2AD to keep the valve train from disintegrating... Supposed to keep a film on the parts for a longer period...
MMO is more like Drano for the engine...
Steve Pierce
BENEFACTOR
Graham, TX
Having worked on several small Cont. engines that used MMO religously I think it keeps carbon from sticking. It is wet on the metal parts. I couldn't tell the difference between the guys using it in the oil and the ones using it in the fuel. I do know it eliminated sticking valve problems. Go to Broadhead WS. and look at all the antiques running OX5s, Hissos, Lamberts, Kinners etc. They have 5 gallon buckets of MMO. Good article on it in this months Cub Club Clues. I would take some of it with a grain of salt. Seems the military used it in round motors by the 55 gallon drum.
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StewartB
Here's a twist. How about STP? Anybody use it?
SB
To clarify my original question...I use MMO in my fuel, NOT my oil.
SB
To clarify my original question...I use MMO in my fuel, NOT my oil.
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StewartB
4 oz. MMO per 10 gal. gas.
SB
SB
Steve Pierce
BENEFACTOR
Graham, TX
I knew someone who used STP in a Tri-Pacer that was blowing a lot of oil. I wouldn't recommend it, it is mineral base though. I use a 50/50 mix of mineral oil and STP as an assembly lube when building up new engines.
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StewartB
Steve,
A local engine builder here recommends STP for the life of the plane. I know some guys that use it, including some 135 float operators. They swear by it, because they get no corrosion when they use it. Up here, corrosion will kill a motor faster than anything. I hear the arguments about multi-vis versus straight weight oils, then hear guys put MMO in the straight weight. I don't see how diluting the oil can be beneficial in regards to corrosion. I also can't find any data to support putting it in the oil at all, other than old radial engine stories from WWII. So, if a guy uses some STP, the oil may be thicker at startup, but the corrosion is reduced. Lycoming suggests a 15% mix of STP to oil in their overhaul manual, for engine assembly. They refer to the mixture as preservative oil. They never mention MMO at all. Like I said, I use MMO in my gas. I was taught to, and always have. Top oil makes sense to me. I'd like to know how MMO affects the properties of motor oil. Like shear strength or oil film left on parts after 10 days. Nobody that uses it seems to know.
SB
A local engine builder here recommends STP for the life of the plane. I know some guys that use it, including some 135 float operators. They swear by it, because they get no corrosion when they use it. Up here, corrosion will kill a motor faster than anything. I hear the arguments about multi-vis versus straight weight oils, then hear guys put MMO in the straight weight. I don't see how diluting the oil can be beneficial in regards to corrosion. I also can't find any data to support putting it in the oil at all, other than old radial engine stories from WWII. So, if a guy uses some STP, the oil may be thicker at startup, but the corrosion is reduced. Lycoming suggests a 15% mix of STP to oil in their overhaul manual, for engine assembly. They refer to the mixture as preservative oil. They never mention MMO at all. Like I said, I use MMO in my gas. I was taught to, and always have. Top oil makes sense to me. I'd like to know how MMO affects the properties of motor oil. Like shear strength or oil film left on parts after 10 days. Nobody that uses it seems to know.
SB
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StewartB
Cuby,
That's my point. I've never seen an engine manufacturer suggest adding solvent or penetrating oil to the crankcase for constant service. An hour or two before oil change, maybe. With AD oils, probably not even then. I'm not saying it's wrong, just that nobody has a scientific reason to use it. How is it affecting the lubricant properties of your oil? How good is MMO at keeping your cam coated between flights?
SB
That's my point. I've never seen an engine manufacturer suggest adding solvent or penetrating oil to the crankcase for constant service. An hour or two before oil change, maybe. With AD oils, probably not even then. I'm not saying it's wrong, just that nobody has a scientific reason to use it. How is it affecting the lubricant properties of your oil? How good is MMO at keeping your cam coated between flights?
SB
FlipFlop
Registered User
Maintaining at Flight Level Zero, requesting lower
stewartb said:
SB...
We're saying the same thing, only in a different language...
I use MMO in my fuel, I don't use it in the oil... There's already enough detergent in Aeroshell for normal operations... If I had stuck rings, clogged passages, etc. I'd run some MMO and then CLEAN SCREENS as the MMO definitely knocks the crap loose... MMO was an asset to big radials running non-detergent oils, even then the MMO wasn't run all the time...
MMO is not snake oil, it really works, but it's not the cure-all for all ills...
Now, a MAJOR disclaimer... MMO is NOT APPROVED for certificated engines or airplanes... Use it in one and you risk your insurance being invalid and your airman certificate being confetti...
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StewartB
Hans,
One pint per oil change is what I was told, and I've watched guys put 2 pints in IO-520's. MMO says 4 oz/gallon of gas. I'm not advocating everyone should use this stuff, I'd just like to hear some real facts. At least with STP, the factory manual recognizes it.
SB
One pint per oil change is what I was told, and I've watched guys put 2 pints in IO-520's. MMO says 4 oz/gallon of gas. I'm not advocating everyone should use this stuff, I'd just like to hear some real facts. At least with STP, the factory manual recognizes it.
SB
Be careful with oil additives. If perchance you are flying an engine with an internal starter drive (i.e. cont. 520) you can mke things to slick. A 210 owner found that out with slick 50. Cost him 2 starter drives and shop time. Betcha the next time he listens to his Mech.
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