Just wondering here.. ( incase gas prices start cliaming again.. ) What works and whats a waste of time on the FE'e?

 

I *just* got my 390 converted to run E85. It seems to like it a lot. No mileage results yet. I'm not expecting much, as I did not build the motor specifically to run E85, and it has compression more in line with a gas motor.

Really, it shouldn't be that hard to run an FE on propane or E85. The principles are the same as any other engine. Jack the compression up, get the fuel to air mixture right, set the timing where the engine likes it.

I've had the "E85 FE" idea for quite a while now. Eventually, since I like building oddball engines, it evolved into a E85 4.0L V6. See here: https://www.ford-trucks.com/forums/5...e-a-motor.html

Basically, for E85 anyway, you want the dynamic compression around 10:1. Then, build the motor how you would otherwise build it.

Here's a conservative chart showing fuel octane vs. dynamic compression ratio:
http://popularhotrodding.com/tech/03...press_07_z.jpg

 

So unlike propane.. E85 is not a easy switch from one to the other.. IE I cant just fill with E85 one day and gas the next?

 

Well here's the thing. Both E85 and propane have a much higher octane rating than gasoline. E85 is 105, propane is about the same.

If you were to build a motor optimized for either fuel, taking advantage of it's high octane rating, you could not switch back to gasoline. To do so would cause the engine to ping badly, probably resulting in it's untimely death. If you want to switch back and forth, you have to build an engine optimized for the lower octane fuel, gasoline, and then just adjust fuel delivery for E85 or propane.

But you lose a lot of efficiency by having the ability to go back and forth, with either fuel.

 

Ya.. its just that a thought... But I have run Propane and gas as duel fuel before and just adj timing ( changed chips ) and it worked well.. but E85 would run thru the carb just like gas.. So I dont think I could do it as duel fuel E85 and gas ) if it came down to it.

 

To do that you'd probably want some kind of fuel injection. The new "flex fuel" vehicles have a conductivity sensor in the gas tank that detects the percentage of alcohol in the tank and adjusts accordingly. I think that would be difficult with a carburetor. Unless, you had a dual carb intake and dual tanks with a switch? But then the fuel distribution might not be up to par.

 

Well .. I guess if it comes down to it.. it could be dual fuel useing Gas and propane, or E85 and propane.. Sound like the timing part would be closer with E85 and propane also..

 

Yeah, I would go E85 and propane. Chances are good you'll find one or the other. Plus, you can build the efficient high compression motor that way.

 

Im not doing a build right now.. just planning agead.. Someone in the past did a major build on this one all ready.. cant run anything under 92 octane without it pinging big time..

 

So re-tune it and run your E85. The motor will thank you. You'll be able to put all the timing back in that the motor likes, and it'll run smoother. It'll never ping again.

 

E85 not here yet.. but if this new law passes it will soon be...The problem is I do a lot of traveling.. from Coast to coast and finding one fuel over another can be a headache from time to time..

 

Interestingly, cross-country may actually be quite easy, if you plan your trip:

http://www.e85refueling.com/

 

I have read in an article recently in one of the truck mags,that you have to upgrade your fuel tank to 600 series stainless or polyethelene because E85 is so corrosive.Did you have to build/buy a new tank,Rusty? How do I learn more about E85?

 

I saw your post and if your looking for more information on E85, try looking at the November 2006 issue of Carcraft. It has a 6 page article called " The E85 Solution". It covers the carb aspect of an E85 build plus some other aspects of the engine build.

 

Thanks slinger!