<VV> Gasahol

[Padgett]

>I understand the gas-alcohol blend can damage some
>seals and rubber parts in fuel systems.

Believe most kits and replacement units were upgraded to modern nitrile 
rubbers sometime in the '70s. Of course if the parts are original or NOS (I 
never use NOS rebuild kits for fuel related items) you may have a problem.

Brazil converted some time ago to almost  a 50% blend. The following is from:
http://www.ieiglobal.org/ESDVol1No1/brazilianalcohol.pdf

* The second category is due to the corrosive behaviour
of ethanol. Some ''typical'' solutions (ANFAVEA,
1986) are listed below.
-- Fuel tanks: tin coated (electrolytic) steel, 7um.
-- Filling nozzle: tin coated (hot immersion), 100g/m2.
-- Fuel lines: pump to tank, polyamide (nylon 11);
pump to carburetor, nitrile rubber.
-- Carburetor surface: Electroless nickel (Zamak, Cu-2um, Ni-5um).
-- Fuel pump finish, steel, coating with Cd-Ni-dichromate (10um).
-- Cylinder head gasket fire ring: stainless steel.
-- Valve materials and seats: hardened.

Now the good news is that alcohol is an octane enhancer however I would 
expect gas companies to reduce the octane of the base stock (cheaper) and 
use the alcohol to bring the octane rating back to the usual PON. The bad 
news is that it take more gasohol (lower BTU/liter) to go a mile than 
gasoline so MPG takes a hit. I vaguely remember 10% from the last time it 
was used.

The limiting factor without considerable modification (richer jets, etc) is 
8-10%. Brazil uses more because the government decreed it so and they have 
a *lot* of sugarcane to turn into alcohol.

So how big a deal depends on the blend: under 10%, not much. Remember that 
Indy cars have run on "alky" (pure alcohol) for all time.

Padgett