Home made E50 for racing?

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gregsdart

gregsdart

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Just thinking about cheap alternatives to straight E85 that might work in an unmodified carb. Let's say a guy has a 11.5 to 1 compression iron headed motor and wants to get by on a budget. If a test kit was used to see the true % of ethanol a little math could be used to determine a mix that would be e50. No data to support the next two comments, just a guess. Would e50 be able to run well at 11.5 to 12/1 compression? I would hope so, but that is probably the upper limit if you use 93 octane to mix.
The other thing is I picked e50 because it should only require a 20 percent increase in jetting to run well, so carb mods to run e50 might be limited to shooters and jets. Comments?
 
You can run that on pump gas. But, there is no reason you can’t do why you are suggesting. It would take someone who has done alcohol carb’d stuff to say for sure if just a jet and squirter change would get you there. I’m not sure how much alcohol (I’ve never used ethanol, only methanol and never with a carb so I don’t know if there is a difference in specific gravity between ethanol and methanol or any other differences) you can get through the internal passages in the metering block and main body before you run into the issue of the passage being the limit not the jet.
 
alcohol corrodes stuff bad in regular carbs and eats up rubber hose's and fuel cell foam that ant compatible! to what extent and what needs done idk but i know its a issue that needs to be delt with! also, the more alcohol is in it the more moisture it will want to absorb so good storage procedures are a must!! alky burns cooler than gas to!
 
Pump E85 during the winter months is often around 50% alky. Summer mixes are higher.

Today's rubber FI hose that is sold in parts stores today is alky compatible.

You can drain the carb for long term storage, run it out before you shut down the engine or have a small one quart tank that you switch on and use that to start and shut down your engine.

I have two methanol carbs I bought used... Not one sign of corrosion after several years of use before I bought them. Not everyone has issues.
 
gregsdart said:
Just thinking about cheap alternatives to straight E85 that might work in an unmodified carb. Let's say a guy has a 11.5 to 1 compression iron headed motor and wants to get by on a budget. If a test kit was used to see the true % of ethanol a little math could be used to determine a mix that would be e50. No data to support the next two comments, just a guess. Would e50 be able to run well at 11.5 to 12/1 compression? I would hope so, but that is probably the upper limit if you use 93 octane to mix.
The other thing is I picked e50 because it should only require a 20 percent increase in jetting to run well, so carb mods to run e50 might be limited to shooters and jets. Comments?
Click to expand...
Here you go

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gregsdart said:
Just thinking about cheap alternatives to straight E85 that might work in an unmodified carb. Let's say a guy has a 11.5 to 1 compression iron headed motor and wants to get by on a budget. If a test kit was used to see the true % of ethanol a little math could be used to determine a mix that would be e50. No data to support the next two comments, just a guess. Would e50 be able to run well at 11.5 to 12/1 compression? I would hope so, but that is probably the upper limit if you use 93 octane to mix.
The other thing is I picked e50 because it should only require a 20 percent increase in jetting to run well, so carb mods to run e50 might be limited to shooters and jets. Comments?
Click to expand...
I am contemplating the same thing.
Even straight pump e85 is way cheaper than race gas.
My concern is getting a consistent blend. What test kit are you looking at?
Since my car is still in the build upgrade path, I went ahead and plumbed the fuel lines with Teflon hose.
Also shortly I will be taking my 3 gallon fuel cell while it's still new,
For hard anodizing and outside powder coating so that it will be compatible with any fuel. The new Holley hp carbs are also black anodized for use with methanol or alcohol.
 
The question is not about detonation with 50% ethanol. It's does a gas carb have the metering block's to supply the increased fuel volume to run 50/50? I run e85 to a motor at about 12.5:1 compression. My gas carb is insufficient. I'm betting you run lean no matter how much you turn the screws up? If someone has experience with pushing the carbs limits? I would be interested.
 
cojohnso said:
The question is not about detonation with 50% ethanol. It's does a gas carb have the metering block's to supply the increased fuel volume to run 50/50? I run e85 to a motor at about 12.5:1 compression. My gas carb is insufficient. I'm betting you run lean no matter how much you turn the screws up? If someone has experience with pushing the carbs limits? I would be interested.
Click to expand...
Well in my limited experience, it's about both. My x headed 340 that I drove on the street in my younger days had a satisfactory fuel mixture with the x heads and a stock Holley 750(before the advent of hp carbs)
When I built my w2 340 with this same carburetor and the biggest #99 jets all around, it was as lean as can be.
I took the carb to a specialist in Hamburg New York(Ray Murray)
and he did his thing to it and then had perfect mixture with 68 and 69 jets in the same carburetor. He said the difference was the out of the box fuel curve was not designed for a high performance head.
I have never used any alcohol fuels, but my research tells me you need a fuel specific carb.
 
I agree Duane. It is about both. But post began with motor at 11.5:1 compression. Thus detonation is not a concern for 50/50 mix. (As fuel matrix shows.) Thus the question? Can a gas carb produce the required fuel flow? I'm guessing not well. There are plenty of E-85 conversion kits to solve the issue. But of course. Now you have the opposite problem if you elect to run on gas. Solution? I have 2 carbs. A gas carb in the trailer. Lol.
 
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cojohnso said:
I agree Duane. It is about both. But post began with motor at 11.5:1 compression. Thus detonation is not a concern for 50/50 mix. (As fuel matrix shows.) Thus the question? Can a gas carb produce the required fuel flow? I'm guessing not well. There are plenty of E-85 conversion kits to solve the issue. But of course. Now you have the opposite problem if you elect to run on gas. Solution? I have 2 carbs. Lol.
Click to expand...
Good info. I may do the same. My thoughts were to plumb the car with Teflon. Anodize the fuel cell and then can use any fuel without issue. I still have my reworked 750 to get me started, but I probably need a 950 with 410 motor.
My problem is how to bracket race with a fluctuating e85- e50 fuel mixture and be consistent. Any advice there you can shed?
 
I have not played mixtures. I just run E-85. My thought is why would I? I have already committed to E-85. Why add a more expensive fuel? It is a whole different question for someone who has not committed. Thus looking for options
 
cojohnso said:
I have not played mixtures. I just run E-85. My thought is why would I? I have already committed to E-85. Why add a more expensive fuel? It is a whole different question for someone who has not committed. Thus looking for options
Click to expand...
You use pump e85 or aftermarket?
 
Duane said:
You use pump e85 or aftermarket?
Click to expand...
Pump. And yes. There does seem to be a difference. Even a difference between stations. The problem with all alcohol is that it will absorb water from the air over time. Newer the better. As well as don't leave in tank or carb bowls for extended period of time. A month seems to be ok. It also evaporates faster than even water. Thus even higher H2O percentage over time. This is some what true for gas too. But not as dramatic.

Like everything in performance. Always a cost!
 
cojohnso said:
Pump. And yes. There does seem to be a difference. Even a difference between stations. The problem with all alcohol is that it will absorb water from the air over time. Newer the better. As well as don't leave in tank or carb bowls for extended period of time. A month seems to be ok. It also evaporates faster than even water. Thus even higher H2O percentage over time. This is some what true for gas too. But not as dramatic.

Like everything in performance. Always a cost!
Click to expand...
Do you find the performance of the engine changes from batch to batch.
How do you bracket race with e85 with a fluctuation fuel mixture.
 
Typically at WOT there is little difference. But at idle? I have seen a difference. I have a couple places I prefer. And a couple that I avoid.
 
It's like anything I guess. The station by my house sells I believe the best non-oxy 91 octane fuel my Street GTX loves. But my truck hates their diesel.

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