I have used ethanol on one Briggs-Stratten engine and methanol on several 100, 250 and, 360 cc motorcycle engines. ALL required major mods to fuel flow and carb jetting. On the Briggs I used a remote fuel tank and larger fuel hose with a 7/8" Dellorto and adjustable main jet. No problems at all.
Methanol required flushing the fuel system, but ethanol did not give any problems between uses.
Almost forgot, I did boost the CR and advance the ign. timing on all.
I have seen evidence of field problems in marine engines reportedly using E10. Some resin components of some fiberglass fuel tanks can supposedly be dissolved by the E10 and redeposit in large quantities on the intake valves. These valves were big, but fiberglass tanks should perhaps receive special scrutiny if used for small engines too. Plastic tanks should be OK though.
"Several states that are required to use reformulated gasoline containing oxygenates (to combat ozone pollution) have banned one oxygenate, MTBE, due to ground water contamination concerns. The only practical remaining oxygenate is ethanol."
MTBE: Methyl tertiary butyl ethane is a gasoline additive which increases octane rating.
I think that MTBE is banned pretty much nationwide now. So the next cheapest alternative is ethanol, which works as both an oxygenate and octane booster. Unfortunately it takes more energy to make ethanol than you get from the fuel.....but that is for another post.
Most frequent problem I've run across is on carburated equipment that is not used on a regular basis. Fuel inlet controll needle that uses viton or whatever trademark name is assigned to the rubber like material used at the tip, is compromised after periods of storage. Also attacks diaphram of mechanical fuel pumps. Replacement of damaged parts, disconnect fuel supply and run the engine till it consums fuel remaining in bowl proir to periods of innactivity, fabricate needle replacement needle out of nickel, are the solutions I've tried to overcome the problem. Also the hydroscopic nature of the alcohul cases rusting in steel material fuel tanks. Where I live (northeast US) all pump gasoline is E10.--------Phil
"Unfortunately it takes more energy to make ethanol than you get from the fuel.....but that is for another post."
It takes more energy to make ANY fuel than you could ever hope to gain from it. This is a consequence of the first and second laws of thermodynamics. The problem with replacing fossil fuels is that legacy fuels are already made up for us. The energy was absorbed by the plants eaten by dinosaurs. We didn't really have to make it. We just fix it up a bit and use it.
I'm personally against the use of ethanol for economic/political reasons (regarding the shifting of crop priorities) and for its pollutants (such as acetaldehyde). I'm not in charge, however, so I'll make do with what is given. I would imagine (disclaimer: guess) that the lower combustion temperatures and richer mixtures would be more favorable to reducing nitrous oxide emissions.
As far as small engines... they rarely last long enough to really worry about much. Something else will break before the fuel eats the carburetor diaphragm. Aren't they using plastic pistons in those things these days? It's horrible, but it pays their bills I guess.
I'm also on the east coast and all of the fuel out here is 10% ethanol. I can't imagine that there would be a dangerous difference in afr's because of 10% ethanol especially at the compression ratios that those engines run. If it's on a go-kart or something that will see a lot of throttle then i might re-jet, etc. But, i wouldn't bother with a lawnmower engine or the like.
Not to go off on a tangent (though that's pretty much what i'm doing), peak oil is a dangerous theory especially since there are contradictory theories that not only hold water- but aren't calling for massive changes to our energy infrastructure.
Elastomers compatibility is one concern. API publication 4262 addresses vehicle emissions. API TR 939 D addresses stress corrosion cracking of carbon steel in ethanol. Other studies pertain to ethanol storage. Lot's of gasoline has included 10% ethanol for decades.
In addition to agriculturally based ethanol, it is also made from ethylene. Ethylene is made from hydrocarbons downstream of the refining or gas processing markets. For automotive use, congress wants farm based ethanol to assure votes from farmers. This also gets votes if considered as renewable energy, regardless of the natural gas used for the fertilizer and additional energy for the conversion.
Ethylene based ethanol is used in the food and pharmiceutical products. Agricultural ethanol is used in our gasoline engines. Makes perfect sense to me.
