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Old 06-25-2013, 12:02 PM   #54
SourKraut
Beastly Adventurer
 
Joined: Nov 2004
Location: New England
Oddometer: 6,980
Quote:
Originally Posted by Tripped1 View Post
Yes, they are.

Water isn't the issue, everything metal gets water in it when the temperature changes, in fact if you look at most hydrocarbon combustion reactions the results are usually some amount of CO/CO2 and whatnot and water. Remember when all bikes were still carb'd? Frozen carb bowls? Yeah, not going anywhere for a minute.

Ethanol is significantly more corrosive, this is the issue with plastic fuel tanks on older Triumphs and Ducatis the ethanol, even in lower ratio blends like E10 eats the resin sealer or plastic and the tank starts to deform.
From wiki;

"Ethanol contains soluble and insoluble contaminants.[31] These soluble contaminants, halide ions such as chloride ions, have a large effect on the corrosivity of alcohol fuels. Halide ions increase corrosion in two ways; they chemically attack passivating oxide films on several metals causing pitting corrosion, and they increase the conductivity of the fuel. Increased electrical conductivity promotes electric, galvanic, and ordinary corrosion in the fuel system. Soluble contaminants, such as aluminum hydroxide, itself a product of corrosion by halide ions, clog the fuel system over time.

Ethanol is hygroscopic, meaning it will absorb water vapor directly from the atmosphere. Because absorbed water dilutes the fuel value of the ethanol (although it suppresses engine knock) and may cause phase separation of ethanol-gasoline blends, containers of ethanol fuels must be kept tightly sealed. This high miscibility with water means that ethanol cannot be efficiently shipped through modern pipelines, like liquid hydrocarbons, over long distances.[32] Mechanics also have seen increased cases of damage to small engines, in particular, the carburetor, attributable to the increased water retention by ethanol in fuel.[33]"
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