Re: How can I run on unleaded.

[stans4@ix.netcom.com (Stan Schaefer)]

I have a Northup Aviation book intended for training aircraft
mechanics, copyright was in the late 40's.  At that time av-gas was
totally different stuff from car gas.  It had a higher boiling
point(so it didn't all disappear at high altitude), likewise lower
vapor pressure, same reason.  The book said that the stuff had a
different rating than octane, was arrived at by different means.  It
also said why you can't compare air-cooled aircraft engines with
air-cooled car engines, aircraft engines spend most of their life at
or near full throttle, the load being fairly constant, and at high
altitude.  All in all, apples and oranges.  It probably wouldn't hurt
to run a couple of tanks of av-gas once in a while, but I certainly
wouldn't run it as a steady diet..  The other drawback is the cost of
the stuff.



On Thu, 25 Sep 1997 21:53:45 -0400 (EDT), you wrote:

>In a message dated 97-09-25 18:27:01 EDT, you write:
>
>> I heard a horrible rumor that aviation fuel is not good for cars.  The 
>>  octane ratio is computed differently (noy and RON standard), so the 
>>  computations don't cross apply.  I remeber reading somewhere that 100 
>>  octane aviation fuel is actually equivalent to auto fuel of a low 80's 
>>  octane.  Be careful, I'd cry if we lost another one of our type 3 
>>  brethren to misinformation.
>>  
>Where did you hear this ? Remember that these engines (aircraft/vw) are very
>similar and that the stock timing works fine with the 100LL avgas. At our
>airport, we also have a race track. Several of the local guys (& mother
>mechs)burn this fuel for practice laps as it's much cheaper than the cam2 we
>sell at the track. Also, several other people buy gas to run in their boats
>on the OH river. Another thing is, a friend used to mix race fuel for us when
>I drag raced a lot (mopars) and he said the 100LL rating is why he used that
>for a base fuel. I'm no expert, but from these exercises, it's hard to say
>that the octane rating is much lower than the 100 claimed. It's good to hear
>your concern though ! Just my .02 worth.
>
>kevin chapman