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Old July 8th 08, 01:19 AM posted to rec.aviation.homebuilt
Capt. Geoffrey Thorpe
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Posts: 790
Default Mixing alcohol with gasoline

"Stuart & Kathryn Fields" wrote in message
.. .

wrote in message
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On Mon, 09 Jun 2008 00:10:42 -0400, Sliker
wrote:

On Tue, 27 May 2008 20:34:40 -0700, "Stuart & Kathryn Fields"
wrote:


We saw an experiment where an antiqu indicated horsepower device that
was
used on locomotives was used and an antique hit and miss piston engine.
The
indicated power gage plotted piston position vs pressure and the area
under
the pv curve was power. With as little as 10% ethanol added the loss
of
power was apparent. We also tried acetone, mek and some other octane
boosters. They all had the effect of reducing power.

Stu Fields


They had to run a test to find out that?
Alcohol contains olny about 60% of the power in gas so the power loss
should be quite noticable even with 10%. With E85 you are looking at
close to a 40% drop.
Roger (K8RI) ARRL Life Member
N833R (World's oldest Debonair)
www.rogerhalstead.com


No we didn't have to run a test. It was just a demonstration of his
engine and the internal power measurement device. I had never seen one
of these devices work, so it was a interesting thing for me to observe
the device in operation with different fuel mixtures. The device had a
measure of resolution that surprised me. Further discussions of the
technique lead to ideas of how it might be adapted to measure Hp in real
time on a Lycoming. Further how might that be adapted to show sticky
valves and individual cylinder problems.
Stu


The old mechanical systems don't do well at higher engine speeds, the
signal gets attenuated - pressure tranducers, charge amps, and digital
signal processing is the way to go nowadays. Kistler will modify spark
plugs with a pressure tap to measure the in-cylinder pressures wihout
drilling holes in the cylinder head.

--
Geoff
The Sea Hawk at Wow Way d0t Com
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