well after reading some of the post here i have a question. how much compression would be ideal to get the best proformance and reliability out of ethanol. there is nowhere around here that sell e85, so i would probaly get a still and make my own. i was under the assumption the higher compesson the better for ethonal up to 14-1. now im not so sure.

 

Straight ethanol or E85? E85 is 105 octane, so let that be your guide.

Here's a good article on compression. They go through a lot of BS (well, useful BS anyway) about chamber mods, theory, etc, but there's good information about dyanamic compression and a chart. Dynamic compression is what you really need to be concerned with. Go have a look. The chart is toward the bottom.

http://www.popularhotrodding.com/tec...on_ratio_tech/

According to that, about 10.25 to 10.5:1 dynamic would seem to be the right amount of dynamic compression for 105 octane E85.

So how do you figure your dynamic compression? See this link:

http://www.kb-silvolite.com/calc.php?action=comp

Have fun!

 

well i might run a little stronger blend as ill be making my own. ill check out the links.

 

I would advise you to blend yours to E85, and build the motor for that. That way you'll be able to tune your motor for a fuel you have a chance of getting at a pump elsewhere, if you decide to take a trip for instance.

 

ive thought of that but i dont know of a place that sells e85 anywhere close to me and it would probaly be several years before there is so i dont think it would matter. but i am just building this truck in my head for now and am imaginging more of a hot rod, take to town and mess around type of truck rather than a traverler. i would probaly take the 59 i am building now on a trip which will be built for straight gas. i more just want to prove to myself and other people that ethonal is a viable fuel. any ideal what the octane for say e95 or maybe striaght ethanol would be.

 

I was just thinkin of posting this same question. I live in Nebraska and there are several places where I can find E85. Im about to start building a 460 and I want it to be E85 compatible. Is 10.5 CR too low or just right? Does anyone have any real world experience with building an older motor and running E85?

 

10.5 static compression ratio wouldn't be too low, it'd be "extra safe". Refer to my comments above.

I have my 390 running on E85. It's only about 9.7:1, but it had pinging problems on gasoline that requred retarding the timing. Now running on E85, I can put all the timing in that I want and it never pings.

I've also got an 11:1 engine project going in the 4.0L V6 forum, though that's not completed yet.

59flatbed: If it gets any kind of cold in your area (below 60 degrees for example) you'll probably want to blend your ethanol with 15% gas. That is, if you like being able to start the engine. If it's strictly a summer cruiser, then fine run straight ethanol. But you'll need to denature it anyway to stay legal, so some gas is going to be required.

IIRC the octane number (although it contains no octane, we should call it the "octane performance number") for E95 - E100 is around 110 to 115.

 

Rusty,
On your 390, what other changes did you make to your fuel system? What carb do you run?

 

I'm running a Holley "Commander 950" 700cfm TBI fuel injection system. I'm using standard fuel filters, and "multi-fuel compatibility" hose I got at Napa. Gas tank is stock, and the fuel pump came with the fuel injection kit.

 

Fuel injection? Sounds nice. I didnt know they made a setup for the FE. How do you like it? Hows the milage?

 

They dont make a kit for an FE! It's a universal system. If you've got a 4 barrel Holley type intake manifold it'll work. It does take some brain cells to get it all working right though. Tuning it takes quite a long time, fortunately you only have to do it once (twice if you switch to E85).

Mileage, I haven't figured it up yet, as I'm not done tuning it yet. The motor really seems to like it though. Really, the F100 has been kind of put on hold until I get the 4.0L project done.

 

Ive been reading up on the Commander 950 and I like what I have seen so far. When you get it programed is it easy to switch from the E85 program to regular gas? Meaning if you set it up for E85 and you travel some place where you can only find regular gas is it as simple as plugging in your laptop and switching programs? Also did you have to make any changes to the Commander 950 to run on E85 like the fuel pump? What dizzy are you running?

 

Yes, if you have the program backed up all you have to do is hook up the laptop and send the appropriate program. But you should make sure you have mostly one or the other in the tank; E40 might not work good on either program!

Fuel pump and all other kit hardware is stock from the kit.

I'm running a Ford Duraspark distributor, that I curved myself, with a Crane HI-6 ignition and LX-91 coil. The Commander 950 is not controlling timing. MSD used to make an FE crank trigger that would have been perfect, but in their infinate wisdom they discontinued it. As far as I'm concerned, MSD can take their products and shove 'em up their... never mind.