FE Power Forums
FE Power Forums => Non-FE Discussion Forum => Topic started by: Stangman on April 27, 2026, 10:19:47 PM
-
I believe this has been talked about before but what does it entail to run E-85. Is it as simple as jetting up the carb to run richer.
-
I’m going to assume nobody runs e-85
-
I don't have a lot of experience with it, but the fuel system needs to be E-85 proof.
-
I don't have direct experience either, but I've read that "E-85" can be "up to" 85% alcohol but supposedly it varies quite a bit from station to station and maybe even batch to batch. E-85 compatible vehicles are able to sense the burn rate (or whatever) and automatically adjust the A/F mixture but with a carburetor, it seems like you'd have to be be much more certain of what you were running. Might be doable for a race only situation?
Pat
-
Besides being ethanol proof and re-tuning your carb, you also need a way to deal with or prevent gelling caused by ethanol in the gas. 10% ethanol fuel gels bad enough after just a few weeks of inactivity. The gelling doesn't seem to affect port injection as much as carburetors.
For optimum performance probably want to increase compression a bit and adjust timing curve but good luck with that if the % ethanol jumps up and down from batch to batch.
-
Is it as simple as jetting up the carb to run richer.
Perhaps a nice start, but "no"! :(
. . . . . the fuel system needs to be E-85 proof.
Very true! :)
I've read that "E-85" can be "up to" 85% alcohol but supposedly it varies quite a bit from station to station and maybe even batch to batch.
Correct! And a problem if your purpose was to convert to E85 for the "anti-knock" qualities, as this varies with the "mix"! Testing kits have been created, though I'm not well aware of their accuracy, this to be utilized with each fill-up to determine if a "tune" change might be in order; this both for detonation avoidance and A/F mixture needs. :o
You also need a way to deal with or prevent gelling caused by ethanol in the gas. 10% ethanol fuel gels bad enough after just a few weeks of inactivity. The gelling doesn't seem to affect port injection as much as carburetors.
Again correct! Fuel injection (as currently supplied by the O.E.M.'s) is a "sealed fuel system", this reducing the fuels exposure to the atmosphere. The biggest issue is that the alcohol, being hygroscopic draws moisture from the atmosphere and will continue to do so until saturated. Now, if that isn't bad enough, but then the alcohol is also highly evaporative, so with an "open" or "vented" fuel system it tends to dissipate into the atmosphere, but leaving the water behind and this becomes the headache stuff! >:(
Also consider that if the fuel delivery system, pump(s), filter(s), fuel lines, possibly regulation and even the carburetor, is currently properly balanced for gasoline, it will prove "insufficient", this probably beyond just a "jet-change", for E85. ;)
And then yeah, alcohol is lower in it's B.T.U. production in the combustion cycle, and why it requires significantly more by volume, so unless your combination would benefit from E85 in order to capitalize on a more aggressive state of tune, the net result could be less power! :-[
Scott.
-
I don’t have any personal experience, but follow the subject casually like some others. Getting a little deeper into the question is probably warranted, as others touched on.
Why are you thinking about E85? How are you using the vehicle - race, street toy, more daily driver?
Are you planning on using pump E85 at random filling stations, or buying dedicated E85 barrels from a fuel supplier?
There are now quite a few “Drag & Drive” type events, similar to Hot Rod Drag Week, around the U.S. every year, and quite a few competitors that run E-85, especially if it’s available near the route, if there’s one of these events near you it might be a good idea to check one out and talk to the participants for their experience. Most folks like talking about their combination, providing they’re not deep in a mad thrash. And I do know, like already mentioned, those people all carry E-85 test kits with them, to monitor what they’re getting at the local station, which is why the question of what you plan to use is important.
-
Joe, I have looked into this quite a bit. Not really because I plan to use it in anything, but more because of intrigue and learning.
Here's where I stand: If I were to run E-85 I don't believe I'd buy pump E-85. I would be sourcing it through Ignite Racing Fuel or similar. This is because the pump fuel seems to gum up and after sitting for the offseason would require at bare minimum the carb to be cleaned up. Ignite claims that their fuel wont do this. The bad part is this would kind of take the streetability out of the car unless you want to drive around with a jug of it in your trunk.
If you have the time, listen to this podcast
https://www.youtube.com/watch?v=LjtFGgGLvok&t=28s