Author Topic: E85  (Read 609 times)

Offline retroboy

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E85
« on: August 08, 2020, 08:40:07 PM »
Anybody run a mechanical injection set up o  E85? Since the terrorist attacks years ago I can't just get Methanol from my local joint any more so it's a 40 km drive to get any. I can get E85 at numerous locations and I keep hearing it's an oxygen carrying fuel and the carb guys are getting good results. Can I run it with my single butterfly mechanical injection and do I need to make any changes.? Also I run without any water in the block and I believe the volume of E85 needed will keep it vool same as using methanol.
« Last Edit: August 09, 2020, 02:47:39 PM by retroboy »

Offline denverflatheader

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Re: E85
« Reply #1 on: August 09, 2020, 09:20:50 PM »
E85 popular here in Colorado.  Out on the eastern plains of Colorado, they grow corn specifically for ethanol blended fuel.  From memory, there are 3 classes of ethanol fuel, Class 1 is 85% ethanol and 15% gas, octane is around 104-105.  Class 2 and 3 are less percent of ethanol and higher percent gas, like 70-75% ethanol to 25-30% gas.  Octane goes down with more gas percent.

Ive run mechanical fuel injection, both methanol and a nitro mix, not E85.  If your combustion chamber burns all the fuel and air mixture, you just reached stoichiometric or stoich, a good thing.  Here are some general stoich values for different fuels:

Pump gas.............14.7:1
C16 race gas.........14.8:1
E85........................9.8:1
Methanol.................6.4:1

Answer to your question, yes you can run E85, you will need to make tuning changes.  To achieve the E85 9.8:1 stoich from your current Methanol 6.4:1 stoich, you will need to increase your main pill (area) to reduce fuel flow to your combustion chamber.  How much - just my guess would be a reduction of 20-25 percent as a starting point, and then keep increasing main pill area size slowly to continuing towards leaner.  You may need to change your spark plugs and timing as well.

Not too sure how the engine temperature will fare compared to running straight methanol.  Reducing the fuel ~20-25% running through your engine will no doubt increase temperature.

Offline THE FRENCHTOWN FLYER

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Re: E85
« Reply #2 on: August 10, 2020, 05:59:00 AM »
Whoa.
Just to be clear, one does not want to run a stoichiometric mixture at WOT.
That assumes that every air molecule combines with every fuel molecule in the combustion chamber for a complete burn. Because it is not really possible to react every air molecule with every fuel molecule (e.g., what if the remaining unburnt fuel molecule is at one end of the combustion chamber and the remaining air molecule is at the other end of the chamber waiting for it to come over and "hook up"?) and it is much harder to fill an engine with air vs pumping in fuel one wants to try to use up every air molecule, even if it means introducing a little extra fuel to get the job done. So, for example, in a gasoline engine if stoich is 14.7:1 you typically want to run at around 12.5:1, depending on fuel distribution and other specific engine characteristics.

For an engine running on a nitromethane stoich is 1.7:1 !!! and you want your tune up A/F to be down aound 1.1:1!

One of my engineering buddies once said if you see a Fuel car running down the track and the flames disappear up inside the header pipes DUCK, as the engine is going lean and losing its "fuel cushion" and parts are going to come flying out.

So go a little fatter than stoich, regardless of the fuel being used.
« Last Edit: August 10, 2020, 06:08:24 AM by THE FRENCHTOWN FLYER »

Offline denverflatheader

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Re: E85
« Reply #3 on: August 10, 2020, 07:32:37 AM »
FTF thanks for adding clarification, your explanation easy to follow and helpful.  Alan

Offline retroboy

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Re: E85
« Reply #4 on: August 14, 2020, 04:21:33 AM »
Thanks guys. I reckon I'll go buy some and lean it out, watch my EGT and see how I go.
Cheers