In article fu9Vd.21974$Ze3.3954@attbi_s51,
"LCT Paintball" wrote:

The other major thing that needs to be looked at, is engine compression
ratios. If it is too high, the engine will detonate, and hammer or melt
holes in the pistons, and other important parts. Also, some fuel systems
are
prone to vapor lock.
--
Jim in NC


So, would it be safe to assume that an engine modified to use 87 octane auto
fuel would not run well on Aviation fuel?

No.

What would you do if your auto fueled airplane was at an airport without
access to auto fuel?


Engines designed (or modified) to run on 87 octane auto fuel run on
100LL, with proper leaning. They can have a tendency to foul plugs if
proper care is not taken, however. Mogas STCs allow mixing of aviation
fuel with mogas, in any ratio. The main caveat is alcohol in the gas,
which is a no-no.