Running a V-twin motorcycle on alcohol?

Question

Looks like alternative fuels are the rage. I have heard stories at rallies of some guy converting their bikes to run on alcohol for the extra octane? Anyone have experience with this? I can see this working for a V-twin but what about other engines?

Answer 1

Ethanol alcohol has an octane rating in the 103 range.  If you have modified the engine so extensively that it needs fuel with a octane rating that high, it would certainly help.  The fact that an engine is a V twin has absolutely no bearing on the type of fuel needed or the octane rating of the fuel.

100% ethanol isn't going to work for a street machine but E85 (85% ethanol and 15% gasoline) will with carburator modifications.  E-85 has only around 70% of the energy as pure gasoline, so fuel consumption will go up under the same load.

Answer 2

If you are running it on the street, I can't see any advantage. Dump some booster in the tank.

Answer 3

Was a re-run of American Chopper on last night.

Built an E-85 bike.

No, I didn't watch - had to go to work.