> Paul,
 >
 > It is not correct that range has to suffer by burning
 ethanol. In
 > fact range can increase if you fly above 10,000 ft density
 altitude.
 >
 > The reason is that ethanol has an oxygen content of about 25
 > percent. The effect is like supercharging, or nitrous oxide, or
 > dragsters that use nitromethane which has huge amounts of oxygen.
 > Gordon

 Sorry, this is not correct -- the oxygen in ethanol is
 representative of
 the fact that is has been partially oxidized, in other words,
 partially
 burned. So some of the energy content has been expended over being a
 hydrocarbon. Nitromethane is a different story. The oxygen can
 come free
 of the nitro-groups and combine with any available hydrocarbons.

 You carry less energy per pound with ethanol, how you use it
 determines
 your specific fuel consumption, milage, etc.

 The evaporative cooling effects and octane effects are real, but the
 oxygen content has already been used up ( i.e. not available).

 Bill Schertz

 Bill,

 Thanks for that insight.

 What exactly do you mean by, "partially oxidized?" The way I
 understand it pure ethanol has an oxygen content of 35 percent, so
 all of that oxygen should be available for oxidization, no? (AGE 85
 is only 85 percent ethanol -- the rest is pentane isomerate -- so
 its oxygen content is about 30 percent.)

 The oxygen is the reason the stoichiometric air-fuel ratio of
 ethanol is lower than gosoline -- because when you add the same
 volume of air, there is more total oxygen due to the oxygen embedded
 in the fuel, so you need more fuel to completely oxidize the extra
 oxygen. See the attached table, "Ethanol Gasoline Properties."

 The heat energy of ethanol per pound or per gallon is lower than
 gasoline, as you pointed out. However, the oxygen in the ethanol
 results in better thermodynamic efficiency, so power actually goes
 up. You can see in the attached chart that an O-470 engine running
 on AGE85 has 15 percent more peak power.

 The graphic on flight test data shows that at 10,000 feet a Mooney
 with an IO-360 running AGE85 has a fuel burn at lean mixture that is
 less than the same plane on avgas at 8,000 feet. One of the
 advantages of ethanol is that very lean mixtures can be safely run.


 Regards,

 Gordon.


 Gordon,
 What adverse effects are there on housings when you use Ethanol ? I had
 developed and manfactred seals which resist methanol and future long
 life oil detergints. These could be used on a rotary engines too,
 however I had the impletion that Ethanol, Methanol etc corrod the
 housing.

 regards
 Roderick

 Roderick,

 As far as I can find from the literature, AGE 85 is compatible with
 existing fuel system materials.

 Here are some snippets from I think Baylor University which has lots
 of info on AGE 85.

 Regards,

 Gordon.

Gordon,
While I'm sure the info you provided about operation at 10K and above
is true, I must interject that most of my local flights would be over
before
I even got to 10K feet! Lots of local fun flying never exceeds 4K.
One other item that is rotary specific, does anybody know if there may be
mixing trouble if you run fuel/oil mix? I'm NOT stating this, I don't know.
I'm not a chemist and I don't even play one on TV.

Bill Jepson


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