What is the mechanism for cylinder damage from ethanol?... ethanol free fuel has zero lubricating capabilities - that's the job of the mix oil.
Phase separation in and of itself is not going to score a piston because it results in free water… But the amount of ethanol does not effect the amount of lubricant in the mix, so engine damage would still only be a consequence of running lean.
Phase separation results in free water
and free Ethanol! Ethanol is a solvent… it displaces oil on metal surfaces. Ethanol burns at a much higher temperature than gasoline, and a mixture of air and Ethanol does not “sink” as much heat while being introduced into the engine. If (as you say), “
the amount of ethanol does not effect the amount of lubricant in the mix, so engine damage would still only be a consequence of running lean”, I guess we can mix our oil with 100% Ethanol and safely burn it in our chainsaws… correct? (By-the-way, I wouldn’t try that if I were you)
If the ethanol content varies enough to effect the tuning to the lean side then the operator should hear that and adjust the mixture…
Sure… That’s fine for you and I (to some extent). But small, high RPM two-cycle engines are not just found in chainsaws in the hands of mechanics… those engines are found in all sorts of homeowner power equipment, as well as recreational equipment and toys (some made for kids).
Most small, high RPM two-cycle engines are owned and operated by people with zero idea how to “tune” anything. That’s the world we live in…
If the amount of ethanol in the fuel is changing at the station, then it's doing that for every automobile engine filling up there. Why doesn't it matter…
It does matter, but not in the same critical way… or not usually in rapid catastrophic failure. A large, four-cycle, pressure lubed, liquid cooled engine running 3000 RPM just ain’t the same thing as a small, two-cycle, fuel lubed, air cooled engine running at 13,500 RPM. And autos have large fuel tanks… getting a 3 second douse of 50% Ethanol in a 20 gallon tank won’t have the same consequences like it would in a 1 or 2 gallon storage can.
Having said all that I think ethanol in fuel is a terrible idea, but more because it takes more energy from oil to make the ethanol than you get back, and because I think burning food is dumb.
I could not agree more.