Ethanol (E85)

bran3b · #1 (**permalink**) 08-27-2003, 07:10 AM

What would happen if I used Ethanol (E85) in my Cobra? It has 105 octane and is supposed to give te same performance. With the high octane I should even be able to advance my timing a little without any detonation. Has anyone tried this?

petek · #2 (**permalink**) 08-27-2003, 08:14 AM

Good question. I saw a segment on some car show last night about E85. Sounds interesting and frankly I'd rather burn a fuel based on corn grown in the U.S.A. rather than liquid dinosaurs pumped from the Middle East!

Mr.Fixit · #3 (**permalink**) 08-27-2003, 08:41 AM

I haven't heard of E85, but when you convert a motor to run on alcohol (cheapest high octane fuel) you need to do a lot of fuel delivery work because the stoichiometry of burning alcohol makes the air:fuel ratio get cut in half roughly. That's why you have to add big float bowl extensions, much larger jets, bigger fuel pump, etc. When you run a roots blower with alcohol, they usually pin the rotors to their shafts because of the volume of liquid getting pumped through the blower. Maybe this E85 is different. Back when I was a college student studying ecology, I learned that the energy inputs to grow corn then convert it into ethanol, are greater than the energy output of burning the ethanol. But as long as we're paying farmers to NOT grow corn....

bmalone · #4 (**permalink**) 08-27-2003, 08:48 AM

I could be wrong, but isn't ethanol corrosive to rubber hose?

scottj · #5 (**permalink**) 08-27-2003, 08:49 AM

I've run 98% pure methanol. An engine requires 2.2 times the methanol and 1.6 times the ethanol compared to gas. At 85% you would need about 1.4 times as much as gasoline. Without a carb (or injection) change you would be very lean.

Pure alcohol also produces about 10% more torque than gasoline. The factors that cause the increase in torque are the same factors that require a different cam than a gas engine or a substantial amount of power is wasted out the exhaust pipe.

Advance the timing? If your timing is optimal advancing it will decrease power. If your timing is retarded, alcohol will allow you to optimize it. I ran 4 deg. LESS timing on alcohol.
Scott

mbishop · #6 (**permalink**) 08-27-2003, 08:59 AM

I saw the Autoweek program last night on E85, very interesting. As scottj stated you'd need over a third more fuel with E85 because ethanol has a lower BTU.

Here's a link I found last nigth with a lot of info.
http://www.e85fuel.com/faqs/conversion.htm