Orval Fairbairn wrote in
news
In article ,
Bertie the Bunyip wrote:

Orval Fairbairn wrote in
news_r_fairbairn-D13E8E.10215613052008@70-3-168-
216.area5.spcsdns.ne
t:

In article ,
Bertie the Bunyip wrote:



Tell me this, what do you make of his claim that you can pour this
stuff straight into an airplane set up for Avgas? No timing or
mixture changes, no hardware changes?

Timing? probably, if the octane rating is there.

Mixture? You would probably have to adjust mixture accordingly. The
different fuel density would probably require adjustments to float
levels.

Other hardware changes?

I would have to see the materials compatibility tests before I
started using it. It has been known since the 1950s that the
synthetic rubber used in hoses, etc. can tolerate either
petroleum-based or parrafin-based fuels.

The problems arise when switching (either way) between the two,
since each type fuel has its own effect on the polymers.

Well, my luscombe had virtually nothing in the fuel system vunerable
to anything this side of Skydrol, but only because I installed a
metal float and an automotive fuel line. The float seat is metal of
course and there's nothing else in the system that anythign can melt.
My KCAB is anouther thing altogether. The LeBlond I'm going to have
to check, but I think it has a standard MS carb form the thirties
anyway, so it should be fine.


What about the flexible hose from the gascolator to the carburetor? I
would not use a hard metal line because of engine vibration and
flexing.

We made one up from an automotive line that was resistant to every fuel
we intended to put in, including ethanol. I couldn't tell you which it
was now cause the airplane is gone. I'll ask the guy who made it up for
me what it was, though.

It is the synthetic materials use in hoses that is mentioned in my
reference.


Yeah, I figured, but there's all sorts of other rubbers and platics in a
modern system as well.

If you can find one (I found mine by accident) a good reference is:

"Aviation Fuels and Their Effects on Engine Performance,"
NAVAIR-06-5-501
USAF T.O. No. 06-5-4,
prepared by Ethyl Corp
supplied to
U.S. Air Forces
on Purchase Order AF-33(600)5312

Dept of the Navy BuAer
on contract No. 52-2002
Copyright 1951 by Ethyl Corp.

It is a comprehensive guide to aviation fuels and potential aviation
fuels and lists energy output, vapor pressure, octane rating, density
and numerous other pertinent qualities of those fuels.

It makes specific note of the potential materials compatibility
problems when switching between fuel bases.




Good stuff!

Bertie