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 Post Posted: Tue Mar 09, 2010 6:51 am 
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Ok I gotta ask. What is the infatuation with E85 anyway?

I have never even seen or smelled the stuff but IMO fuel is such a small part of the racing expense why all the trouble?

Plus you mid western guys are the only ones that can even get your hands on it.


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 Post Posted: Tue Mar 09, 2010 7:03 am 
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Scott Smith wrote:
Ok I gotta ask. What is the infatuation with E85 anyway?


its a good alternative to expensive race fuel, were going just as fast or faster than we were on 110 and 112 octane for around $2.30 a gallon. even if it takes 30% more fuel were still going faster for less money per pass than before.

and 9 out of 10 times the only thing needed changed is the carburetor.

it allows for more people to be able to afford racing again.

were talking $130 per barrel of fuel vs $600 per barrel.....I can go racing alot on $470 difference.


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 Post Posted: Tue Mar 09, 2010 9:53 am 
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Drag Chevette wrote:
E85 ....the fuel itself likes to maintain a constant relative velocity and composition throughout the carburetors channels.
(years of E85 research tought me this....dont ask why, im telling you this is what E85 likes,)

Any fluid that has high viscosity flows better if there is minimal area transitions. Transitions not done correctly cause turbulence and turbulent flow is probably more detrimental to the linearity of the curve as the viscosity increases, but Im not sure on that exactly.
Drag Chevette wrote:
my carbs are set up with a slightly larger than gas mainwell, and nearly no emulsions, complemented by the right size boosters....(again, years of testing)
this maintains a nice even velocity and flow throughout the circuits.

So do you use emulsion or not?
I agree its the booster thats the problem with alcohol carbys, but your saying that E85 has to be dense leaving the booster, well isnt that really saying we cant get enough out of this hole?????.
What Im saying is to further your knowledge and improve yourself go build a new booster and play with emulsion more with that booster.
Drag Chevette wrote:
I take other companies E85 carbs all the time and fix them for my calibration, and most of the time my calibration will gain .2-.3 in the quarter over their calibration....why?....most the time I take away emulsions and increase velocity while controlling the top end through boosters and bleeds.

they are thinking along the lines of gasoline or methanol, not in unconventional terms like Eric and I...


Increasing density increases the Reynolds number, increasing viscosity reduces it. Higher viscosity reduces the Reynolds number. With ethanol the viscosity difference to gasoline far outweighs the density effect on Reynolds number.
E85 maintains laminar flow through the main well for much higher power levels. Under laminar flow conditions the flow rate is linear to the pressure differential.
Your controlling the top end enrichment problem that is applicable to all booster carburetors by allowing the flow velocity to go later into turbulent Reynolds number flow compared to gasoline, however that is a technique that is more affected by the temperature of the fuel. By choosing to allow the viscosity to have more influence to the fuel curve you at the whim of the viscosity change with temperature. But it is a valid approach to E85 or straight ethanol. It is not unconventional thinking it is correct for the physics of ethanol and I hope you may now understand why. A competent carburetor designer would understand that so thats a complement to you.
I do not know your main well diameter but even if its moderate between methanol and gasoline sizing its going to be at laminar flow to just into transitional flow and that transition point will vary with the temperature for a moderate 500hp engine. So the AFR will vary with dips etc due to temp. The severity of the effect i do not know.
I would expect the main jet itself to be going into turbulent flow at 120hp so the temperature will affect that load point too.


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 Post Posted: Tue Mar 09, 2010 1:11 pm 
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Its available here around the Seattle area
I just bought 100gallons $@2.20 from the local refiner =D>
Thats a lot better than the $11.00 i was having to pay for the race gas here
My other interest is that its runs quite a bit cooler on my blown application ,have not got to the track yet (end of April)but am looking at having the extra help of .02-.04 to get me into the 9s .
I had Mark modify my original 1050 Dominator and I purchased a second Dominator from Eric68 both work great and the difference in throttle response is noticeable even with my limited engine experience.
Both Mark and Eric are very knowledgeable and helpfull about E85 and I would not hesitate to recommend them =D> \:D/ ,as for an established carb builder getting peed off :-({|= :-({|= i suspect its because its now very apparent that there are people out there who are willing to educate and help without it ALL being about the bottom line $.
Thanks Mark & Eric
Roy

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 Post Posted: Tue Mar 09, 2010 2:23 pm 
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shrinker wrote:
Any fluid that has high viscosity flows better if there is minimal area transitions. Transitions not done correctly cause turbulence and turbulent flow is probably more detrimental to the linearity of the curve as the viscosity increases, but Im not sure on that exactly.


I think this was the biggest factor in the carb he tore apart, Large mainwells hitting the smaller angle channel has to be disruptive. And while surface turbulence in intakes and cylinder heads can be beneficial, I don't think you want any more turbulence from the main passage than you already get from the transition points, like the transition from the mainwell to the angle channel in the metering block. A passage with the least interruptions will make it easier to control the fuel curve.


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 Post Posted: Tue Mar 09, 2010 4:27 pm 
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Once a flow stream is high enough in Reynolds number to be turbulent, an area transition shaping that creates turbulence doesnt alter the flow rate much, its already turbulent. When the flow is laminar or transitional and there is an area transition that creates turbulence then its another matter. You have just created turbulent flow and thus altered the fueling of the engine at a point where it should have been linear to the depression. When people talk about smoothing this or that etc and how great it works that's what their actually talking about.
What is important is to maintain conservation of flow condition. These small variations in flow become observable engine tune factors. Because we are dealing with a liquids volume ratio that is affected by flow changes and comparing it to a gas (air) the AFR sensitivity is extreme. There is such a small amount of liquid per cylinder fill that you would think its not important but thats just why it is important. A very small change in delivered volume of liquid to the booster is a massive change in AFR. Thats why less emulsion smooths out the fuel flow rate from the booster but then you have to control the booster limitations another way. Thats precisely what Mark and Eric have done over the years of testing. An emulsion bubble takes up space that could be used for fuel and the exit point at the booster gets more 'crowded in' as you increase CFM. You can take that effect to the extreme if you have too much emulsion air. Thats what is common nowdays with all this marketing about emulsion patterns, more is not better if its not correct design.
Its not that E85 likes anything, it doesnt know what the world is about, its just a dumb liquid, the problem is that there are carburetor tuners and there are carburetor designers. The difference in viscosity of ethanol to gasoline or methanol means that the carby has to be redesigned not just tuned. Carby gurus who swap parts in a Holley are not designers; they can operate their business within the limitations of the design of the Holley carby but present them with a difference like viscosity and they get lost. Mark and Eric are using the correct approach to ethanol but there are limitations to that singular approach. What Ive been saying is if they broadened their horizons they would be better at designing and not just tuning.
There are far more designs of carburetion than the one chosen by Holley.


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 Post Posted: Tue Mar 09, 2010 4:50 pm 
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shrinker wrote:
There are far more designs of carburetion than the one chosen by Holley.


Like this?
Image


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 Post Posted: Tue Mar 09, 2010 5:30 pm 
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I'd like to point out that the design of a carburetor is not the appearance or the re arranging of circuit position's. Its the physics chosen to perform tasks. Yes my carby is different physics to a Holley and so is an SU. I have designed a different carburetor, not tuned a Holley. But its only one option available on this planet.
An important aspect of carburetor design is to design the engine as well. If you approach building a car without trying to design it as an integrated package you end up with a bad car. Each design of carburetor has an optimum style of engine design and useage pattern to bolt underneath it. It extends all the way to tailpipe tip. I dont make a carby and ship it in a box, never have and never will. I go to each and every customer and consult and design a carby for that engine, or I redesign the engine. I wont tolerate a situation where the engine design has to be bandaided by the carby.

Designing a carburetor is a lot harder than tuning one, I think that an E85 fixed venturi Booster style carby hasn't been correctly designed yet. Maybe Mark might do it, maybe what Ive said here will kick him into gear, its enough to start him off on the track of necessary research. I'm not going to spoon feed the guy, I'm just poking him in the ribs a bit to wake him up.


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 Post Posted: Tue Mar 09, 2010 8:54 pm 
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damn it....they need to take the time out thing off this..

lost another long post because I had to log in again....

going to start typing them in word then pasting it over.

anyway,
shrinker....spent 2 days track testing boosters and came up with the best available for the application.
using holley style I tested in numeric bit size from 28-8 (.140-.199) and found the one that worked the absolute best.
then started playing with stepped to see how that worked.

spent 2 more days doing HSAB....

there has been 1000s of hours put into these calibrations between Eric and myself....

and so far Eric or Myself have NOT seen another E85 calibration thats close to what were doing.

Quote:
What is important is to maintain conservation of flow condition. These small variations in flow become observable engine tune factors. Because we are dealing with a liquids volume ratio that is affected by flow changes and comparing it to a gas (air) the AFR sensitivity is extreme. There is such a small amount of liquid per cylinder fill that you would think its not important but thats just why it is important. A very small change in delivered volume of liquid to the booster is a massive change in AFR. Thats why less emulsion smooths out the fuel flow rate from the booster but then you have to control the booster limitations another way. Thats precisely what Mark and Eric have done over the years of testing. An emulsion bubble takes up space that could be used for fuel and the exit point at the booster gets more 'crowded in' as you increase CFM. You can take that effect to the extreme if you have too much emulsion air. Thats what is common nowdays with all this marketing about emulsion patterns, more is not better if its not correct design.


Exactly ....and thats what is wrong with conventional E85 carb building .

a small amount of Emulsion can and will effect E85s bond and cause the extreme sensitivity you spoke of and will often cause unstable fuel flow and make the carb inconsistant if conventional tuning is used.

this is where Eric and I have excelled over conventional thinking.
as emulsions are introduced the flow speed or velocity within the mainwell is increased, causing hyper behavior in the E85 fuel flow....our mainwell/emulsion configuration allows for slight emulsions without changing or disrupting the fuels velocity towards the booster.

our mainwells, exit channels, and booster sizes were developed over a few YEARS of testing E85 only, and they are designed to work together....to get the correct velocity and volume without fuel disruption.

in another companies E85 carb the fuel was very disruptive flowing due to mainwell size, emulsions, bleeds, and boosters this carb had been tweaked and calibrated to maintain a flat fuel curve.
I took this carburetor and used unconventional tuning and recalibrated it to my tune up...again a flat fuel curve.

however, due to the smoother flow of fuel throughout the whole carbs range, the carb I calibrated netted .37 quicker ETs in the quarter while A/F numbers were almost the same for both carbs.....think about that one for awhile.....???

thanks for making me think...my head hurts now....shrinker and tuner should get together and hold a siminar...Id pay alot of $$$ to take notes for a weekend listening to them talk about carbs.

have a good day.


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 Post Posted: Tue Mar 09, 2010 9:29 pm 
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Hello Mark, I dont have to think about the comment of same lambda with more power because I have been preaching that to people for years. Tuning is not about Lambda it's about efficiency and it's better to use a gas bench to observe that. Efficiency as far as the intake air stream is concerned comes from atomization and homogenization. Over emulsifying the feed to a booster does not cause better homogenization, IT MAKES IT WORSE. What I'm explaining to you is the physics factor that you need to understand in order to correctly reason why the difference in E85 viscosity requires less emulsion. You can take it up from there if you wish.
You have demonstrated the testing to achieve your results and thats good because you have now experienced a small part of what you need to go through to design a better carburetor for E85, not just tune one.


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 Post Posted: Tue Mar 09, 2010 9:54 pm 
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shrinker wrote:

You have demonstrated the testing to achieve your results and thats good because you have now experienced a small part of what you need to go through to design a better carburetor for E85, not just tune one.



Did I just get the Shrinker stamp of approval? ;-)


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 Post Posted: Tue Mar 09, 2010 9:57 pm 
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Well you have questioned conventional 'wisdom' and found it to be lacking and you sought a solution. Thats exactly how I started.


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 Post Posted: Tue Mar 09, 2010 9:57 pm 
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shrinker wrote:

Eric-- I realize the double edged sword of emulsion but thats why there is a maximum main jet sizes that works with a venturi and booster design. it seems to me that the booster is the weak link in the E85 fuel debate. The main jet has to control the AFR of the whole system, the e-bleeds have to be used to trim small details, but you have to change some details when the volume of fuel flowing through the system is greater. I understand that the main well needs to be larger for E85 but I dont understand why emulsion is not of benefit. I think that removing the emulsion is a crutch for another issue. The physics of why emulsion was better was established in 1926 and it hasn't changed since then. The problem with a booster within the main venturi is that the vacuum generated by the booster is only representative of the central flow rate of the main venturi. That problem was recognized prior to 1926 and it was solved by the e-bleed system then. Without e-bleeds the fuel flow does not follow linearly with the air flow, its get richer and richer as you increase flow. Plenty of carbys have been built that dont use air compensation but they are restricted to use on that exact mass production engine or at best they are hard to adapt for hotrodders. There certainly tunable but its not as an adaptable design as the emulsion carby. In the early days of motoring there was a lot of changes with fuels and it seems that we're about to go through something like that again with the greenies etc, so a stable fuel like straight Ethanol is looking pretty good except that they go and bugger it up with adding gasoline to it. An emulsion is basically a pretty good thing for a booster carby to have and it smooths out a lot of problems and smooths out a lot of issues that crop up when fuel changes etc and that's what E85 does yearly.


I think maybe you have misunderstood me somewhere along the line -- I never said that emulsion is a bad thing with E85. I don't think Mark did either. TOO MUCH emulsion IS a bad thing with E85 (just like gasoline) and in my opinion .040" high speed bleeds AND e-holes are too much. I understand the history of emulsion a.k.a. air correctors and I think you'll find that throughout history NONE of the OEMs (certainly not any Holley stuff) used any sort of craziness like a .040" air corrector. Now I'm sure there is an oddball out there but I think you know what I mean here. If E85 is just a dumb liquid like you say why would it need a .040" high speed bleed? ;-)

I agree with what you are saying about the booster. I've got that part worked out for my carbs and I hope you'll understand why I don't share any details on boosters. :-# I will say that there are a few configurations that work well with E85 and some that don't work with a damn. I'm not saying that E85 needs anything exotic, it just needs the right configuration. IMO if you need to over-emulsify a carb to get it to respond, that is covering up some other flaw, not the other way around.

While I understand what you are trying to say, I don't know that I care to be labeled as a carb tuner or a carb designer. That's what the big companies try to do to us little guys -- label us as something unattractive and boast about there $1M CNC machines. I build carbs -- I start with a bag of parts, work my own boosters, work my own metering blocks, and build a carburetor that suits my specs -- specs that I have worked out through a lot of experimenting and testing over the last 4 years. Granted, I did not take the same approach as the big guys did but I think that my practical approach is what makes my stuff work so well. I wouldn't be so bold to say that I design carbs, Holley did that, but I would say that I do a bit more than tuning ;-)

I hope I don't sound argumentative, just discussing is all.

While we're on the subject, what configuration would you use for an 850 Holley E85 carb?


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 Post Posted: Tue Mar 09, 2010 10:09 pm 
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No offense taken, and there is more to the equation than what I've posted here, give mark a call some day. As far as an E85 holley goes, as I said before the fuel has only just become available here and its only in one petrol station so no experience with it yet, but after thinking about this exercise I know what I will do with my carby. Besides i dont think you would want me to post the details of how i would design an E85 fixed venturi booster carby.


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 Post Posted: Wed Mar 10, 2010 12:17 am 
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shrinker wrote:
i dont think you would want me to post the details of how i would design an E85 fixed venturi booster carby.


Wanna bet!!!! :-$ Seriously, I think you are trying to inspire everyone to look at different ways to make them better on their own, I don't believe anyone here would miss that post. It's a tricky deal, getting the carb to meter fuel correctly without being any more restrictive than necessary to get a tunable signal, and getting the fuel sufficiently atomized and evenly distributed for the given engine combination. Which then goes back to making the engine as efficient as possible at keeping the fuel suspended and mixed evenly, and getting the combustion chamber to burn the mixture efficiently.


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