Flex Fuel (51-83%)

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Jonnylightening

Jonnylightening

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So I'm in the process of converting my 408 to E85. At my local pump they have Flex Fuel (E85) but it's rated at 51-83% Ethanol. Question is if you have your tune set for 85ish % what do you do? For instance when you do the water/E85 test and come up with say 51% what can you do to bring it up? The whole point of the conversion is to get the high octane rating at a cheaper than race gas price. Any help is much appreciated!
 
Buy some alky and a hydrometer and add your own? We have no such thing here in Idaho. "a few" stations (darn few) have non-alky fuel, and most stations have the whatever it is 10-15% stuff.
 
Jonnylightening said:
I'm a newbie at this so what alcohol would I need to buy?
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Straight methanol. Apparently it's not cheap. 99.9% pure from a race gas supplier, not so much. Looks like $60/5gals.
You will need a way to check and confirm your mixture. And the MTX gauge is a great idea.
 
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Jonnylightening said:
I'm a newbie at this so what alcohol would I need to buy?
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I only know any of this from having a "Variable" fuel car from the early 90s. it was supposed to run on 100% gasoline to 100% M85 as in Methanol or any mix in between (it was part of an experimental fleet of cars in So Cal) it had special injectors, fuel pump and controller.

Ethanol - Grain Alcohol (AKA Everclear 95% alcohol, 5% Water?) (or make your own! MOONSHINE 100% Ethanol)

about 15.5 gallons of Everclear to 2.5 gallons of gas will get you in the range of 75 to 90 % Ethanol (assuming my calculations are correct.)

I think racing alcohol is still Methanol - Wood alcohol (supposedly nasty stuff to humans through casual contact)

I would expect your EFI to adjust the spray time for O2 output?

So if you had spray nozzles that could deliver the 2-3X the volume needed of gas nozzles it should self adjust for the 50 to 80 variation in E85





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Dana67Dart said:
I only know any of this from having a "Variable" fuel car from the early 90s. it was supposed to run on 100% gasoline to 100% M85 as in Methanol or any mix in between (it was part of an experimental fleet of cars in So Cal) it had special injectors, fuel pump and controller.

Ethanol - Grain Alcohol (AKA Everclear 95% alcohol, 5% Water?) (or make your own! MOONSHINE 100% Ethanol)

about 15.5 gallons of Everclear to 2.5 gallons of gas will get you in the range of 75 to 90 % Ethanol (assuming my calculations are correct.)

I think racing alcohol is still Methanol - Wood alcohol (supposedly nasty stuff to humans through casual contact)

I would expect your EFI to adjust the spray time for O2 output?

So if you had spray nozzles that could deliver the 2-3X the volume needed of gas nozzles it should self adjust for the 50 to 80 variation in E85





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Only downfall is I'll be running a E85 carburetor. Idk if maybe the mix is so low due to it being the enter months? They say they add more gasoline in those months due to starting issues bug I'm not 100% on that
 
Buy e98 by the drum and mix with non ethanol non leaded pump of the highest octane available. If just works better unless you buy racing e85 by the drum. It's less expensive than buying the e85 by the drum, though.
Ethanol % Calculator
 
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Jonnylightening said:
Only downfall is I'll be running a E85 carburetor. Idk if maybe the mix is so low due to it being the enter months? They say they add more gasoline in those months due to starting issues bug I'm not 100% on that
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My mistake I thought you were going EFI.

the starting thing is real. I recall reading about it in the owners manual supplement and they had to do some odd things to get the engine to start and run reliably when it was cold out.

If it was me I would want to know what % fuel I was running and supplement till I had the mix I like.
 
I was talking with a E-85 racer and he was saying that the amount of alcohol in E-85 will fluctuate to as low as 70 percent and as high as 90 percent. He also was saying that as long as it's above 65 percent it's all good. He has a turbo LS with over 1300 hp.
 
My understanding is E85 requires larger jets because more fuel is reqd compared to non-E fuel. So I presume there will be a sliding scale from 0-85%.
 
my 11/1 , carburated 367, normally burns 87E10. I accidentally filled it up with something once, that I had to assume was E-85. I was on the side of the road three times in 15 minutes, upjetting the primaries. I had a dash-mounted, dial-back, timing box, so that took care of the different ignition requirements. It was on a roadtrip, so wasn't so bad, but I was more careful after that.
 
You will have to jet the carb up or down depending on the % of the e85. The tune will definitely change and you have no other way to compensate for it. E85 at the pump does vary from summer to winter and I’ve seen as little as 55% and as high as 91% here in so cal. You will have to keep specific jetting notes and test your e85.
 
OR you could keep it simple and stick with pump gas.
 
Haven't seen E85 at the pump around here either. For a long time.
 
Garrett Ellison said:
Buy e98 by the drum and mix with non ethanol non leaded pump of the highest octane available. If just works better unless you buy racing e85 by the drum. It's less expensive than buying the e85 by the drum, though.
Ethanol % Calculator
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There is a company about 4 hrs away from me that sells E98 by the drum. I haven't had time to see if there were any other local companies but it's on my to do list. Compared to a drum of VP110 if I were to mix it it'd still save $$$ even for the drive
 
Just a thought.....
Do you have access to avgas? Works for me in a 50/50 (or less) mix with pump 91/10%. for a 10 1/2 iron head 440. (I can run it on pump, but now I don't have to).
And the avgas here is cheaper than pump premium in california.
 
Jonnylightening said:
I'd love to run pump gas but my engine is an iron headed 408 with 11.47:1 compression. Even with my cam it still puts me on a VERY fine line. Personally I'd rather not take a chance
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Get the timing curve correct, get the coolant temp down to 180 at the very hottest, make sure you have the correct heat range plug and then don’t drive the car like it’s a stock engine. In other words, don’t drive down the road at 30 MPH in high gear and mash the throttle. That’s too much load and it will rattle.

Some day, probably by late summer Im going to do some videos on pump gas engines using higher than 11:1 compression ratios. On how to do it and why you should do it.

FWIW, unless you severely heat load the engine (like a long climb without downshifting) you can and should run the same compression ratio with iron heads as you do aluminum heads.
 
Jonnylightening said:
There is a company about 4 hrs away from me that sells E98 by the drum. I haven't had time to see if there were any other local companies but it's on my to do list. Compared to a drum of VP110 if I were to mix it it'd still save $$$ even for the drive
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What carb are you running? It’s not just a jet change to run E85. It takes a much different tuning package than gas.
 
Jonnylightening said:
It's a E85 Converted Holley 750DP
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Well that helps. Hopefully they used a very efficient, high gain annular booster, because the amount of fuel moving through that carb is close to double that of straight gasoline. Plus, all those ethanol based fuels are much more viscous than gasoline.
 
Rat Bastid said:
Well that helps. Hopefully they used a very efficient, high gain annular booster, because the amount of fuel moving through that carb is close to double that of straight gasoline. Plus, all those ethanol based fuels are much more viscous than gasoline.
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Lol that's all I know about it...it was converted from a carburetor shop somewhere in Tennessee. It had very low run time on a running car. They drained the bowls and cleaned them before they stored it
 
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