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MOGAS STC

Seaworthy

FOUNDER
Massachusetts
I need some info from you folks in AK or wherever who use a lot of MOGAS. KPYM will shortly be selling certified ethanol free mogas for A/C. Octane is UNK. I have a PA-12 with O-320A with 150 hrs currently on it.

I read the Petersen STC info and the one caution that they offer is beware of RPV factor in warm weather re vapor lock. They also state that octane affects volatility. (Higher volatility may lead to increased probability for the production of carb ice) What they don't state is: the relationship between octane and volatility. Does increased octane equal higher volatility? I would assume it does, but we all know where assumptions take you.

The reason for the questions and its importance is that my engine for whatever reason is an ice machine. As soon as relative humidity approaches 80% I have to seriously worry about ice. Once it starts it comes fast and the engine doesn't just gradually start losing power. It' loses power at a startling rate----like it scares the crap out of me.

The question is: Would I be prudent to stick with 100LL or get the STC and try mogas?

Thanks much.
 
Those are interesting links Seaworthy. Thanks for posting them. It once again raises the question as to what fuel is suitable for a cub and what is not. I don't think I will ever get a clear answer on that.

Shane
 
EAA ( who also sell the STC) also has a long explanation re MOGAS.

It seems that if you have a 150 HP or higher engine, or if you fly in hot climates, or areas with large OAT swings, then you could be asking for problems using MOGAS. The more I read, especially re lower octane and engine knock and the resulting damage, I wonder if it is wise saving a few bucks viz a vis either wrecking the engine or substantially moving up TBO.
 
Seaworthy, One thing is for sure, if you never try auto fuel , you'll never know how it works for you. Seems that if others have good luck with it maybe you might too.
 
Seaworthy I've got a 150 hp cub and a 160 hp cub and both have the auto gas stc and I use auto gas in both of them in the lower 48 and in Canada,AK never had a problem yet and the stc has got my butt out of tight situations more than once. Try it you'll like it.
 
We have been using car gas from the gas station for the last 25 years in our pacer that has an O-320 B2B and it just got overhauled at 2200 hours. we've never had the STC my dad has just been too frugle to pay for the 100LL.
 
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