Calling all E85 fuel experts

[Darth Fiero]

FYI: E85 fuel is an alternative fuel that comprises of 85% ethanol and 15% gasoline, is approx 105 octane, and costs less than regular unleaded gasoline.

Supposidly it is not compatible with conventional fuel systems (mainly rubber components) but there is some information out there that says it also requires all steel components in the fuel system need to be of the stainless variety.

My question for the E85 experts is: What in a stock 80's GM EFI car's fuel system isn't compatible with E85 and why? I can understand that rubber components in the system may dry out after prolonged use but what about the steel components? What about the plastic components (like fuel tank internal baffles)?

 

[Ormand]

Here's a quote from the US Army:
"E85 can be stored in aboveground or underground tanks of cold-finished or butt-welded steel construction. Fiberglass tanks should not be used with E85 unless they are lined with chemical-grade rubber to prevent the fuel from contacting the fiberglass. Any storage or dispensing components made from zinc, brass, lead, aluminum or other soft metals should be replaced or avoided when converting an old gasoline tank, or planning for a new E85 tank"

So, looks like the FIRST problem might be the fuel tank, which is zinc coated. The second problem will be a loss of power, since E85 has less energy per gallon than gasoline, and has to burn richer. So, for a given injector size, there will be less power available from E85. Your mileage will go down, too, because of the richer A/F ration. There may be more, but it's money in the pockets for Archer-Daniels-Midland, and some of the other midwest corn producing companies. And, you will be subsidized by the rest of us, since E85 gets some tax breaks.

 

[87 Pete]

Try searching www.ls1tech.com

They have done several writeups on converting LS1 f-bodies.

IIRC, you need to change the fuel pump, feed and return lines, and injectors (use alcohol safe o-rings). Not sure about the fuel rail and regulator. I think the tank was okay to leave, at least on an f-body.

Though E85 may be cheaper per gallon, I believe it does not have the same amount of energy (per gallon) as gasoline, so you need to burn more than a gallon of E85 to go as far as you would on a gallon of gasoline.

Pete

 

[Darth Fiero]

Try searching www.ls1tech.com

They have done several writeups on converting LS1 f-bodies.

IIRC, you need to change the fuel pump, feed and return lines, and injectors (use alcohol safe o-rings). Not sure about the fuel rail and regulator. I think the tank was okay to leave, at least on an f-body.

Though E85 may be cheaper per gallon, I believe it does not have the same amount of energy (per gallon) as gasoline, so you need to burn more than a gallon of E85 to go as far as you would on a gallon of gasoline.

Pete

True, and I agree I will probably not get as good of fuel economy using E85 as opposed to gasoline. But the thing I am looking at is the fact that E85 is 105 octane and is cheaper than reg unleaded. Sure beats leaded race fuel that sells at more than $4/gal around here plus the E85 doesn't kill O2 sensors.

Thanks for the info!

 

[turbofish38]

I assume your E85 is the same as M85? The M is for methanol. Back in 92-93 Chevrolet offered a M85 Lumina. The entire fuel system was stainless steel. Everything including the fuel tank and the special braided SS fuel hoses. It used a special low lubricity fuel pump and of course the hotter alcohol coils that we use on our type 2 coil conversion. I have some friends that run alcohol in thier race cars. A lot of extra work draining the fuel system just so the fuel doesn't screw something up when the cars sit for more than a day. Sounds like your asking for trouble even with a deluted mix of 85%.

 

[ijames]

No, the E85 is 85% ethanol, M85 is 85% methanol. Methanol is more corrosive and picks up water faster.

 

[HellOnWheels]

Just finished my ethanol still a couple days ago and planned to be distilling the first run of 190 proof fuel grade ethanol by now, BUT trans went down in the Grand so the moonshine will have to wait.

I've read several articles that most all states have at least 10% ethanol in their fuels. My plans are to start using the 10% mixture then slowly increasing until I can run at least the E85 stuff. There are a lot of engines that are not AFV's that are running the E85 stuff but I have my doubts about that.

If nothing else I will use the pure stuff in Razors system thats on my car.

I just like the idea of being a lot less concerned on the price of a barrel of oil.


HOW

 

[ijames]

Um, even if you do get 190 proof from your still that is still only 95% ethanol and 5% water. Mix that with gasoline and I think you will get separation into two phases, with the water rich phase on the bottom where your fuel pump pickup is. The ethanol blended with gasoline is 99.9+% alcohol. They used to do that by adding some benzene to form a ternary azeotrope and then distilling that off. Nowadays I think they use molecular sieves to extract the water, then they dry the sieves, then they use it again, etc. Ideally you would collect the vapors from drying the sieve and recycle that back into your still since it will be pretty alcohol rich. In your alcohol injection system the 190 proof would be just fine, however. Molecular sieves aren't all that expensive, so if you are really interested I could try to dig out some old references on solvent drying to see which one works best with ethanol.

 

[HellOnWheels]

Um, even if you do get 190 proof from your still that is still only 95% ethanol and 5% water. Mix that with gasoline and I think you will get separation into two phases, with the water rich phase on the bottom where your fuel pump pickup is. The ethanol blended with gasoline is 99.9+% alcohol. They used to do that by adding some benzene to form a ternary azeotrope and then distilling that off. Nowadays I think they use molecular sieves to extract the water, then they dry the sieves, then they use it again, etc. Ideally you would collect the vapors from drying the sieve and recycle that back into your still since it will be pretty alcohol rich. In your alcohol injection system the 190 proof would be just fine, however. Molecular sieves aren't all that expensive, so if you are really interested I could try to dig out some old references on solvent drying to see which one works best with ethanol.

There is a product known as Zeolite to which you dump in the 190-195 proof ethanol, let it set for a while (?), strain out the Zeolite and you have 200 proof ethanol (100% alcohol). Dry out the Zeolite and it's ready to remove the water from the next batch. There are other ways to draw out the water but this is what the backyard distiller uses.

HOW

 

[novaderrik]

i can't comment on the long term effects of E85, but i can say that my 84 T definitely runs better on the stuff. just putting a half a tank on top of half a tank of 93 octane felt like a 50 hp incresase. it literally felt like a different car with no perceptible pinging at 17 psi, where 93 would ping loudly at 13 or so psi.
as for fuel economy, it usually gets slightly less mpg than 93 octane, but the lower costs of the fuel itself made the costs per mile go down. i also tried mixing it with 87 octane, and it ran exactly the same as with 93 octane. the only real downside from a drivability standpoint is the way it feels like a carbureted car with an improperly adjusted choke when it's cold- sputters and dies if you put it into gear without a short warmup. but let it run for 30 seconds, and it runs perfect.
and, actullay, on one tank i put about 3/4 of a tank of the stuff in on top of an already 50/50 mix of 87 octane and E85, and i got 22 mpg on a 100 mile cruise at 80mph down the interstate. the best it got before was 17 or so.
i just got a tranny put in the car after it sat with a full tank of E85 for almost 3 months, and it started right up and runs like a beast. i'll see what the tank looks like inside whenever i get around to putting a bigger fuel pump in it.

 

[Jerryl]

Some good info on Methanol anf Ethanol fuel characteristics.
http://www.geistware.com/rcmodeling/glowpower/fuel_characteristics.htm

 

[ijames]

Zeolites are molecular sieves - that's one of the old, common, names for them. There are many types, however, with names like 3A, 4, etc, and I don't remember offhand which one is the best for drying ethanol. They are usually in the form of BB-sized pellets. You can either pour them in and stir the slurry, then filter off the molecular sieve, or you can pack a pipe with them to make a column, and pour your liquid through that. The column method generally does a better job but it is less convenient for the drying step. The vapors from drying the sieve will contain a lot of ethanol, plus the extracted water, so you should condense them and put them back into your still to recover the ethanol.