Mogas in a 337?

[Nick Bailey]

I read in CPA forums about the many cesna single owners who are using mogas with success. Any Skymaster owners out there using mogas? With avgas prices getting ridiculous, it seems like a much more economical way to go even if some modifications are required.

[Dale Campbell]

I can give you two cases where mogas is a no-no. A few years ago at our local airport, a couple guys where killed because of mogas. The two where delivering a second plane for annual on a hot day in July. They arrived dropped off plane, sat on ground for a half hour in a Cessna 177. Started engine, taxied to runway.
When they where about 200 feet off ground, engine quit. They tried tunning back to runway and crashed, killing both. NTSB found auto gas that vaporized in gas line and carborator.
The second case less than a year later. A guy in a J-3 Piper Cub on take off just a few feet off runway. His engine also quit because of vapor lock. Also hot day and using auto gas. Managed to make a safe landing. Remember auto gas was formulated for water cooled engines that get no hotter than 220 degree. Aircraft engines that are air cooled run much hotter. Most aircraft engines run in the 400-500 degree area . Auto gas boils at a much lower tempature than av-gas. Unless you live in Alaska I would not even concider it.

[Jose L. Ichaso]

There is an STC for mogas use in some Cessnas like 152, 172 not for 182 and 206. I asked for it for our 152 Aerobat at my local flying club, and it`s just filling and comply with some paperwork, add some decals, to have the stc. I was impressed there was not,any mechanical work or add on item to have it, and it is limited for certain type of engines.
I know one 206, a 310R and a B-55 Baron , that had been flying with mogas for more than two years, without any problem (as long as I know). They say there is not vapor lock risk in places like the tropics, were the outside temperature is very hot all year round.

Regards,

Jose L. Ichaso