On Mon, 28 Feb 2005 22:40:34 -0500, "Morgans"
wrote:


"LCT Paintball" wrote in message
news:17RUd.77210$tl3.9758@attbi_s02...
They usually are kinda expenssive in the short run, but will pay
off after a quanity of cheaper fuel has run through it. The fuel must
have
no alcohol, though.
--

What is kinda expensive?

STC's could be a hundred, to several hundred, or thousands if new pistons
and stuff for an engine are required. Top of head info only; I've never got
an auto fuel STC.

Why no alcohol?

Most airplane fuel systems and engines contain parts that do not react well
to alcohol. Some hoses and gaskets can swell up to more than double their
size.

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

Just a note, that is not due tot he alcohol though.
Alcohol raises the octane rating with the maximum coming around 10%.
This is strange as Alcohol by itself has a very low octane rating.

holes in the pistons, and other important parts. Also, some fuel systems are
prone to vapor lock.

My IO470N for one. The high compression and heat can be a real bear
in the summer for hot starts. OTOH it's built for the 100 octane
avgas.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com