I have been risking my luck posting an off topic thread on the canard list regarding alternative fuel and thought I should spread my sins around and pass it on to you folks on this list as well. I am also very interested to here all your thoughts on using this stuff in a rotary. I was doing some research on E-85 an 85% ethanol based fuel substitute being promoted here in the Midwest and sent an email to one of the study groups asking for any info regarding a replacement for 100LL. I will paste their response as it is very interesting.
Denny
Denny,
These comments ignore two vital items. First: All alcohol fuels suffer a mileage penalty compared to gasoline. This is true of many alternate fuels. BTU's per pound just aren't there. The engine may run fine, but will suffer a mileage penalty of 30-50% depending on how well the engine is tuned for alcohol. Rotaries are very tolerant of low-octane fuels, but suffer even bigger on mileage.(compression ratio limited I think)
Second: Alcohol will attack many composite surfaces including laminates. (fiberglass and Carbon-fiber) The solvent aspect may far outweigh the BTU's/pound problem. Different solvents attack different items. Rather obvious but this simple test will show you the difference. Take a PERMANENT sharpie marker and on a piece of aluminum make a couple of marks. Let them dry and then take a petroleum product and try to remove one of the marks. I have found even strong solvents (like lacquer thinner) won't touch the stuff. Get some 90% alcohol the common drugstore stuff and it will remove the marks almost instantly. Unfortunately it only takes a while longer to dissolve your fiberglass wing! There has been several long discussions about these problems. Gasahol 20% is one of the worst offenders, even worse than straight alcohol.
Bill Jepson
Bill Jepson