E85

[SFSDFGT]

I am still getting acquainted with my Cobra, which supposedly has a 475 ci all-aluminum shelby stroker engine, with close to 12:1 compression. It runs terrific on the Sunoco 110 I have been shelling out the big bucks for, but I am tired of running to the local race garage to fill up my fuel jugs, especially at $9.25/ gallon.

I live in South Dakota, and E85 is plentiful. I am really thinking the smart move would be to convert to E85. Does anybody know of any reason why I shouldn't? This is the carb I am looking at:

http://www.summitracing.com/parts/hly-0-80845hb

I am getting 4+ psi on the fuel pressure gauge, just with the mechanical pump, and when I hit the switch for the electrics, I get 6-7 psi. My thought is I could probably run the mechanical alone 90% of the time, and then just hit the switch for the electrics when I plan to be mashing on the gas more... Which is what I have been doing now. Is there anything else I need to do to convert to E85? Are there other aluminum FEs out there running E85? I did a search, and didn't see much info on this.

[bobcowan]

You may not have to swap the carb. The only issue is that supposedly some of the standard Holley components can't handle the E85. gaskets and seals. You might be able to rebuild your current carb with the new seals.

Same thing with the hoses. Some rubber hoses are supposedly not compatible.

However, E85 is not nearly as caustic as some people say it is. Lots of folks are using it with standard hoses and components without any difficulties.

The big issue is fuel volume - not pressure. You'll need about 20-25% more fuel volume than gasoline. You should first make sure your fuel pump and lines can manage that. All the way from the fuel tank pick up to the carb. 3/8" lines probably won't cut it.

[SFSDFGT]

Thanks for your thoughts. I will investigate the size of the fuel lines and the capacity/compatibility of the fuel pumps. As far as the carburetor goes, I know I can just modify the current carburetor but I would just prefer to have the convenience of an entire carburetor swap so if I ever turn it back it will be more easy.

[Gaz64]

Carb looks good, factory E85 calibration.

Total fuel system upgrade required to convert to E85, since you'll be using much more fuel volume.

Carb Instructions:
https://ac17cb7e3cc3506f0d23-7386afb...r10659rev1.pdf

[joyridin']

There are a LOT of guys on the GM LS forums using E85. They are running 12:1 with 10 psi of boost and getting away with it. 11:1 with almost 20 psi of boost.

Let us know how it works. I was thinking of doing the same thing. I just need to add another tank for all the extra E85 I will need.

[olddog]

Fyi E85 can be anywhere from 50% to 85%. They need more gasoline in the winter or you have starting issues in cold weather. So you may have issues if you tune on summer blend and get a tank of winter blend. EFI copes better because the O2 compensates. Rumer has it that even during the summer, there is a lot of variability.

[SFSDFGT]

Here in SD (where we have ethanol plants all over), some stations have "blender" pumps, where you can the select the percentage of ethanol. Even if that wasn't available for some people, I think running some ratio of e85 to race fuel (3:1, for example) would help ensure against inconsistencies in the e85, and lessen the concerns about fuel volume some, AND ease the pocketbook some at each fill-up.

[WardL]

Most (if not all) race fuel has some kind of alcohol in it. I wouldn't mix a race fuel with E85. When Olddog says 50% to 85%, he means 50% ethanol to 85% ethanol. Ethanol has better than 115 octane and E85 is likely better than 105 road octane. I would get rid of as much rubber in your fuel system as you can before using E85. Stainless steel would be the best fuel system material for e85.

[SFSDFGT]

Originally Posted by WardL

When Olddog says 50% to 85%, he means 50% ethanol to 85% ethanol.

Right, I knew what he was saying.

The percentage of ethanol that varies in the E85 typically is only inconsistent in the winter months, when they may add more gasoline to decrease the moisture-absorptive properties of the ethanol. I live in South Dakota, so we are talking about a car I only drive May-October (sadly). The ethanol content during these months should always be close to 85%.

By the way, my uncle moved to Camarillo a few years ago. I love to go out and visit him. Camarillo is definitely one of my favorite spots on earth. My wife and I are going to get a second home there when the kids are out of the house. I am trying to figure out which of my toys will be the "California drivers".

[eschaider]

Here's a write up by Rocket Brand Racing Fuels about the transition process. It might be helpful as you begin your conversion.

File exceeds the upload size limitations but you can find it here, click => http://www.rockettbrand.com/tech_support.html

Click on Tech Bulletins and look for a bulletin labelled Changing from Gas to E85.


Ed

[joyridin']

My buddy drag races motorcycles and switching to E85 is the hot thing. Some guys use the racing version which has 85% alcohol guaranteed. Most use the street version, which can vary, but you just tune your car/bike accordingly.

They have some way of checking the alcohol content, but they have never seen it below 70%.

[eschaider]

One of many things you need to be careful about with E85 is the 85 moniker has very little to do with the actual ethanol content. Check out what the DOE say that you can label as E85, click here => "Handbook for Handling, Storing, and Dispensing E85 and Other Ethanol-Gasoline Blends"

The ethanol checking methodology available today, for the most part, is totally useless because it is measuring the gasoline content not the alcohol content. Having determined the gas content the sensor infers anything else is E85. This is misleading in the extreme and totally wrong head thinking about how to measure ethanol content. Even the flex fuel sensors from Detroit do the same thing. Check out this YouTube video illustrating the problem;
[ame="https://www.youtube.com/watch?v=8DZhLjwsWVY"]Flex Fuel Sensor Testing[/ame]

As if this is not bad enough our engines are fueled using gravimetric measurements not volumetric measurements. Same as a Top Fuel car. A 90% Nitromethane/Methanol mix is 90% by weight and temperature corrected not 90% by volume. All DOE naming conventions for ethanol based fuels are volumetric, ignore water content and temperature. The difference at low power levels is just a loss of power. the difference at high power levels is parts failure.

Ethanol is hydroscopic, which means it leaches water out of the air around us — and it will if you expose it to the ambient atmosphere. Now you have a new facet of the problem which is the invisible water content of the fuel.

For performance engines if you intend to run ethanol (at any percentage) you ought to get a fuel source that has a high QC standard (not like the DOE) that the fuel must consistently meet to to be labelled E85 or E-whatever. Additionally you need to upgrade many of your fuel system components to survive the ethanol.

This is not as simple a transition as some think.


Ed

[SFSDFGT]

A lot of good info, folks. Thank you, it is appreciated! Not sure what I will do at this point, but for now will probably stick with the sunoco 110 and fuel jugs in the garage. I will mull it over and figure it out this winter, so I can just enjoy the car for a while now.