David
 I have been following a website that is promoting Mazda type rotary
 engines for light aircraft. With only 3 moving parts, there are a lot
 less things to go wrong. You almost always make it home and they are
 cheap to fix. They started talking about using acetone as an
 additive to speed up the combustion so that all the fuel is burned
 from the sparking of 2 spark plugs. They were speaking of a fast
 moving combustion front and I thought that this may be an ideal home
 for Butanol. Butanol for rotary engines. I have been asked how much
 it costs. It would seem to me that with the way that gas is going,
 it may be cheaper to use butanol in planes. Can you help me and
 would you like to speak with Paul Lamar at the above website?

 Peter Duffecy

 David,

 Few things packs such an energy punch as gasoline and diesel or jet
 kerosene, and you will be hard pressed to get the distance you are
 getting from it, from much of anything else. The fuel of choice is those
 products, and the discussion of acetone, Hydroxy, multiple
 sparkplugs  etc is merely ways to ignite the fuel load as quick as
possible.

 Once burning, it will not burn quicker, but if it could be ignited in
 more places than one, the process can be shortened.

 However, what packs the energy, and what does the grunt work, is
 gasoline, diesel or jet kerosene.

 It is of course possible to burn all kinds of fuel in any combustion
 engine, all kinds of gases, or burning liquids.....however the BTU
 out of most other alternatives....to say it frankly.....sucks.

   Certain combinations of methods or compounds can enhance
 performance , or economy, a NOS bottle will not only make you laugh,
 but it will pep up the engine pretty much. A Top Fuel dragster run
 on so much nitro and alcohol, that the compression stroke is close
 to hydraulic lock. A smaller ammount of Propane in diesel trucks
 have, reportedly beneficial effect on the economy, etc.

 Yes an airplane engine , ( or an engine in any vehicle) can run, as you
 suggest on Butanol, ...or Propane...or Hydrogen gas, ...or Alcohol ...or
 basically anything that will burn and can be fed into the engine, ...
 but run the numbers of volume and weight needed in order to be energy
 comparable, and you will be surprised....not to mention the way some
 of it has to be stored, in pressurized bottles.  For the size, and
 weight, you have to come up with some pretty good energy packing
 product to beat gasoline, diesel or jet kerosene.

 You might be able to do a 6 hr flight with gasoline, while you are bound
 to do an hour and a half with alternative fuel. then once you land,
  it is a matter of getting into a taxi with your gas canisters and
getting
 it filled somewhere, if you want to get home again.

 Just because it is possible, and the fuel in question have a couple
 of desirable features ...like ....perhaps....clean
 burning....doesn't mean it is a viable way to go.

 Alcohol, you need roughly twice the tank size if we compare that energy
 with gasoline, so you have a choice, either you keep your tank size
 intact, but fly only half as far, or fly as far, but double your
 tank size...take a pick.

 Same equation has to be looked into for any fuel alternative.

 An equation that works for a city bus, it will not necessarily work for
 an aircraft.

 We have not even touched the issue of existing infrastructure
 yet.....land in Wyoming and when the fuel truck get to you, ask him
 if he has a special on Hydrogen today.

 Roger



For your information;

A number of years ago Detroit Diesel had an experimental program
running a
modified 6V-92 bus engine on M100. When you fired them up they ran like a
blown alcohol or fuel dragster. Then after going for a drive they
would idle
like a normal engine for a couple of minutes. Then the combustion chamber
cooled a bit and back to the rough idle. They had a controller with
LED's on
it that flashed when it turned on glow plugs (taken from the 5.7 Chev
diesel).
It needed the glow plugs because the high heat of vaporization took
the heat
of compression out and it would not run without them.

Medicine Hat, Alberta, Canada had two of these as they have two methanol
plants that were closed. They were interested as a market for methanol
would
get employment going. They finally gave up on these engines. At first the
engine life was only about 50,000 miles. Detroit finally got it up to
100,000
with lubricity additives in the fuel. The large quantity of methanol
sprayed
into the cylinders was washing the oil off the walls. When they
converted them
back to diesel, they had trouble with restarting the engines. Turns
out the
head castings were different internally to retain heat and when they
were shut
off the fuel boiled in the heads and vapor locked.

Bottom line with this is; to change something is not necessarily easy
and many
things will likely need changing. Granted butanol is fairly close to
gasoline
in heat content and required infrastructure, but only a lot of trial
and error
will be required.

Dale Davies



Peter Duffecy,

What is the website you are referring to that promotes rotary engines in
aircraft?  Thanks.

Tom