Frank Stutzman wrote:
Ron Natalie wrote:
You're not likely to see it. One of the criteria for getting that
STC is to flight test for the conditions condusive to vapor locking.
Most commonly they are high ambient temperatures and very low fuel
flow rates, low pressures. In my plane (not approved for avgas) the
^^^^^^^^^^^^^^^^^^^^^^

Ah, er, don't you have a typo there, Ron?

I thought you had converted your Navion to some flavor of 550. To the
the best that I know, all such engines are approved for avgas. If anything
I would say that they are not approved for autofuel.


Ooops...that should say not approved for mogas. I don't know if their
are *ANY* planes not approved for MOGAS.

There are no Navions, regardless of engine, that are approved for AVGAS.
The EAA doesn't get into anything other than 4-cyl I believe. Petersen
at one point test flew a Navion and it failed the tests. They couldn't
tell me what engine or fuel system (the Navion has probably over a dozen
different combinations AS IT CAME FROM THE FACTORY, not withstanding
those put on by STC) was the one tested and failed.

Yes the IO-550 is right out anyway.