$ per mile: high compression/high test vs. low compression/regular
 

On Feb 15, 8:55*pm, Ed Huntress wrote:

"Investigation of Knock limited Compression Ratio of Ethanol Gasoline
Blends"
James P. Szybist, Adam Youngquist, and Robert M. Wagner
Oak Ridge National Laboratory
Wayne Moore, Matt Foster, and Keith Confer
Delphi Corporation

http://info.ornl.gov/sites/publicati...s/Pub21839.pdf

"It was found that at substantially similar engine conditions,
increasing the ethanol content of the fuel results in higher engine
efficiency and higher engine power. These results can be partially
attributed to a charge cooling effect and a higher heating value of a
stoichiometric mixture for ethanol blends (per unit mass of air).
Additional thermodynamic effects on the ratio of specific heats (..)
and a mole multiplier are also explored.

"It was also found that high CR can increase the efficiency of ethanol
fuel blends, and as a result, the fuel economy penalty associated with
the lower energy content of E85 can be reduced by about twenty
percent. Such operation necessitates that the engine be operated in a
de-rated manner for gasoline, which is knock-prone at these high CR,
in order to maintain compatibility. By using early and late intake
valve closing strategies, good efficiency is maintained with gasoline,
but peak power is about 33% lower than with E85."



Ed Huntress

You have left out this statement.

"The higher efficiency of E85 is not sufficient to compensate for its
reduced
energy content relative to RG, thus there is still significantly
higher fuel consumption for E85."


Dan

$ per mile: high compression/high test vs. low compression/regular
 

On Sat, 16 Feb 2013 05:46:19 -0800 (PST), "
wrote:

On Feb 15, 8:55*pm, Ed Huntress wrote:

"Investigation of Knock limited Compression Ratio of Ethanol Gasoline
Blends"
James P. Szybist, Adam Youngquist, and Robert M. Wagner
Oak Ridge National Laboratory
Wayne Moore, Matt Foster, and Keith Confer
Delphi Corporation

http://info.ornl.gov/sites/publicati...s/Pub21839.pdf

"It was found that at substantially similar engine conditions,
increasing the ethanol content of the fuel results in higher engine
efficiency and higher engine power. These results can be partially
attributed to a charge cooling effect and a higher heating value of a
stoichiometric mixture for ethanol blends (per unit mass of air).
Additional thermodynamic effects on the ratio of specific heats (..)
and a mole multiplier are also explored.

"It was also found that high CR can increase the efficiency of ethanol
fuel blends, and as a result, the fuel economy penalty associated with
the lower energy content of E85 can be reduced by about twenty
percent. Such operation necessitates that the engine be operated in a
de-rated manner for gasoline, which is knock-prone at these high CR,
in order to maintain compatibility. By using early and late intake
valve closing strategies, good efficiency is maintained with gasoline,
but peak power is about 33% lower than with E85."



Ed Huntress

You have left out this statement.

"The higher efficiency of E85 is not sufficient to compensate for its
reduced
energy content relative to RG, thus there is still significantly
higher fuel consumption for E85."


Dan

Because that was never in dispute, Dan. Here's what was in dispute:

[JB]

"some/ race engines use ethanol. most don't. those that do use it do
so because it's easier for firefighters to handle, not because it's a
better fuel."

....to which I responded....

[EH]

"Pure ethanol has an octane rating around 115, and it produces *some*
of the evaporative cooling and densification that methanol does. It
produces more horsepower than gasoline...

"USAC never outlawed gasoline, but they changed the rules on fuel-tank
capacity and number of required pit stops for 1965, eliminating the
fuel-mileage advantage of gasoline and favoring the higher power
obtained with methanol."

I repeated, over and over, that gasoline has a per-gallon fuel-mileage
advantage over both ethanol and methanol, but that both alcohols have
an advantage in horsepower output and thermal efficiency. Given their
stoichiometric ratios relative to that of gasoline and other factors,
the result is that either alcohol can produce more horsepower than
gasoline -- methanol more than ethanol. Thus, it's a better racing
fuel, and racers use it where it's allowed.

JB then proceeded to auger himself into the ground. I can't wait until
he brings up the Japanese research. Maybe they re-invented
thermodynamics. g

--
Ed Huntress