STC SA01944CH for M4220C

[Mog]

So does anyone know the details of this STC. It claims to allow Mogas on the M4 220C. I'm not overly concerned about it, but it's interesting non the less.

[TomD]

The STC is issued to the EAA, but there is precious little information on it.

The models include the M4-220.

Seems like quite a trick to have a ~10:1 compression engine run 87 octane unleaded with out detonation.

Am I correct on the CR on Franklin 220's?

[pilot]

Am I correct on the CR on Franklin 220's?

Yep, unless the stc involved reducing timing and having temp limitations, I would pass.

[DeltaRomeo]

I noticed that the EAA auto fuel STC approved engines included all BUT the O-360

Maule has an auto fuel STC as does Peterson. It may be that you need mods to the fuel supply (from Maule) and Peterson provides the engine STC.

Some have argued that if you could successfully use mogas the entire time to TBO, the fuel savings would pay for the engine overhaul.