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E85 Tuneup Development
http://motorsportsvillage.com/forum/viewtopic.php?f=21&t=8533
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Author:  jmarkaudio [ Fri Nov 11, 2011 7:08 pm ]
Post subject:  Re: Another E-85 Convert

Guess my post disappeared. Eric68 is HPI. Looking at what he is talking about is probably with emulsion. QF probably uses the same emulsion as their gas carbs, usually 3 bleeds in the .026 to .028 range, and a .030+ MAB, too much for E85. Eric uses 2, I think because it is a smaller Venturi 950 he gets away with two larger bleeds. Our smaller engine/bigger carb needs the emulsion to correct the fuel curve, but works best with more smaller bleeds.


Which brings me to my next question, because of the viscosity difference between E85 & gas cause a difference in the bubble size formed with a fixed bleed size? In other words, maybe ethanol needs a smaller bleed to keep the bubbles from being too large as they form in the mainwell.

Author:  shrinker [ Fri Nov 11, 2011 7:51 pm ]
Post subject:  Re: Another E-85 Convert

So now I gotta type this all again.
Yes your approach is the way to go for large carbys at low CFM demand with Ethanol blend fuel.

Smaller e-bleeds will create smaller bubbles. However the physics of the size of a bubble that gets formed under the surface of a liquid is a very very complex problem that I know little about. So I don't know an answer for your question as to the actual bubble formation size.

The main reason why you are succeeding with smaller e-bleeds is the point where the fluid flow transitions to turbulent occurs much higher in the engines CFM demand with E85 than with gasoline. With E85 you don't need to apply as much correction. Correction is only necessary for the turbulent part of the CFM demand. Because that's less range with Ethanol you have less correcting to do.

Author:  Ken0069 [ Fri Nov 11, 2011 8:55 pm ]
Post subject:  Re: Another E-85 Convert

jmarkaudio wrote:
Guess my post disappeared.


viewtopic.php?f=4&t=8731

Sorry! Don't know what happened on this but the site was down this morning.

Author:  jmarkaudio [ Sat Nov 12, 2011 12:03 am ]
Post subject:  Re: Another E-85 Convert

shrinker wrote:
So now I gotta type this all again.
With E85 you don't need to apply as much correction. Correction is only necessary for the turbulent part of the CFM demand. Because that's less range with Ethanol you have less correcting to do.


So the small e-bleeds work best at the top of the mainwell, once the air and fuel flow demand go up to the transitional/turbulent point it then needs the larger bleed at the bottom of the well to correct the curve, which isn't uncovered until then.

Author:  shrinker [ Sat Nov 12, 2011 2:09 am ]
Post subject:  Re: Another E-85 Convert

jmarkaudio wrote:
So the small e-bleeds work best at the top of the mainwell, once the air and fuel flow demand go up to the transitional/turbulent point it then needs the larger bleed at the bottom of the well to correct the curve, which isn't uncovered until then.

Yes that is the case however the larger main jet alters the amount that the well head drops. The positions of the e-bleeds for E85 should vertically different to gasoline.

Author:  shrinker [ Sun Nov 13, 2011 3:07 pm ]
Post subject:  Re: Another E-85 Convert

I found this related to bubbles in a fluid. I found lots of other stuff to but this will do.
"As the viscosity of liquids increase, entrained air, now a bubble, can be trapped below the liquid's surface. Increasing viscosity of the system also reduces the coalescence capability of smaller bubbles merging to become larger bubbles. If the bubbles become large enough (increasing the diameter), bubble stability decreases. The surface viscosity is also important, as it effects the coalescence formation between bubbles. The higher the bulk viscosity becomes, the lower the coalescence formation is between bubbles."

This indicates that Gasoline with its lower viscosity is more likely to have bubbles joining up into a big one etc. Ethanol with its higher viscosity (thicker) wont coalesce as readily. So just looking at the problem initially it appears that the viscosity is not a valid reason to have small air emulsion bleeds. It appears that what I said may be the main reason to use them. Its probably more valid to use small bleeds with gasoline, but you would have to use lots of them and thats not as cost effective for the OEM's. Just because a part is made a certain way doesnt mean its the right way for an individual application, it usually just means its the right way for a perceived market position.

Author:  Ken0069 [ Sun Nov 13, 2011 6:32 pm ]
Post subject:  Re: Another E-85 Convert

Shrinker, does that apply to methanol as well, ie, are methanol and ethanol anywhere near the same viscosity? :-k

Author:  shrinker [ Mon Nov 14, 2011 2:31 am ]
Post subject:  Re: Another E-85 Convert

Ken0069 wrote:
Shrinker, does that apply to methanol as well, ie, are methanol and ethanol anywhere near the same viscosity? :-k

Nope. Methanol is within cooee of gasoline viscosity. It transitions flow at the same flow rates etc ,its just that because its oxygenated it therefor requires higher flow rates per hp so it transitions at a lower CFM demand than gasoline.
Technically the emulsion demand for methanol is different to gasoline but its nothing remotely like straight ethanol. E85 is a different matter. I dont think anyone knows for sure what viscosity it is and how it varies with summer winter blends.

Author:  nomad [ Tue Nov 22, 2011 4:17 pm ]
Post subject:  Re: Another E-85 Convert

Just a note. The fella this post was originally all about anyways won Super Pro at Orlando's Night of Fire Extravganza this past Saturday. Not sure what he ran during elims but, in time runs he had three 10.16s in a row. Nope, E85 didn't win it for him but, he told me that repeatability gave him the confidence to concentrate on driving.

Author:  nomad [ Thu Nov 24, 2011 10:02 pm ]
Post subject:  Re: Another E-85 Convert

I've finished our new shop E85 950 HP. BLP alloy baseplate and metering blocks with Braswell booster. Notice the baseplate is a dual pattern for 4150s and 4500s. Costs a dollar more.

Image

Image

Image

We don't expect to be back on the dyno untill after the first of the year.

Author:  Beretta [ Fri Nov 25, 2011 8:47 am ]
Post subject:  Re: Another E-85 Convert

Nice carb stand Bruce =; .......Do you sell them too =;

Author:  nomad [ Fri Nov 25, 2011 11:17 am ]
Post subject:  Re: Another E-85 Convert

Sorry to say I don't sell them. I made that in the early eighties out of a stop sign I found in the scrap pile at work. There's hole you can't see that's the size of an aircleaner. I can flip the carb over and work on the bottom. Pretty simple stuff. I'll post a photo when I can.

Author:  nomad [ Fri Nov 25, 2011 2:57 pm ]
Post subject:  Re: Another E-85 Convert

Bottom side of the 950 sshowing the Braswell boosters.

Image

Author:  nomad [ Sat Dec 03, 2011 9:48 pm ]
Post subject:  Re: E85 Tuneup Development

I spoke to a number of builders at the shoot out about E85. Other than the fact that QFT has some E85 stuff they really don't seem to be too interested. What I heard was: "It's junk." "I hate the stuff." yayaya. The only thing I can figure is that 1.They don't know much about it 2.They don't want good hootch used as a motorfuel.

Author:  F636 [ Sun Jul 15, 2012 11:09 pm ]
Post subject:  Re: E85 Tuneup Development

Hi Bruce, have you had a chance to tune on that hp950 you put together? I'm curious what you come up with. Hopefully I'll get to the track next weekend and I want to try a couple different emulsion packages on my 950!

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