Skymaster should be tested for Mogas STC
 

The Skymaster has a lot going for it ie high wing and no Bendix fuel injection.
Low (and High) fuel pumps as a back up.
If we got the STC then the market value/appeal/utility of our Skymasters would increase.
Vapor lock be a risk even with Avgas and it has happened to Turbo337 drivers.
Can be mitigated with:
https://www.aircraft-spruce.com/cata...ermoshield.php
I would love to see a T337 tested by Mr. Petersen with the thermoshield in place. Or by the EAA. Or somehow by SOAPA.
Any thoughts about getting this going ?

Todd Petersen
 

Said that he has not tested any aircraft for years and has no imminent plans to do so. Also said would depend on number of aircraft out there.
With perhaps eg. 10 or 15 times as many 182's out there as 337's, payback from the market may be suboptimal when considering the Skymaster.
That leaves EAA, SOAP, and anybody out there with enough of an entrepreneurial spirit who would perhaps like an STC with their name on it, and who doesn't mind flying an aircraft around that is filled with hot auto fuel.

Eaa
 

Emailed back and said they have not tested any aircraft for quite some time and do not have any plans or even the means to do so. So if any (non-smoking) SOAP members want their own mogas STC for Skymasters with their name on it then it might be up to them.

Compression Ratio
 

Compression ratio should allow operation in 91 Unleaded:

From the TCDS: Cont IO-360-C has CR of 8.5:1

A C152 with O235-L2C also has 8.5:1 and requires 91UL for the Petersen STC.

With and high and low Fuel pumps, it should pass the Vapor lock tests.

mitch
N5477S