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 Post Posted: Mon Mar 08, 2010 3:26 am 
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Yes ethanol is more viscose but what is E85? The viscosity isnt always a simple extrapolation of 2 values. What Viscosity is E85?


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 Post Posted: Mon Mar 08, 2010 7:09 am 
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I would say,

E85 = .47 Centipoise @ 27*C....or pretty darn near it.

still alot more than gasoline and still harder to flow than gas.


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 Post Posted: Mon Mar 08, 2010 7:12 am 
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Is that what you think it is or is it a measured value?


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 Post Posted: Mon Mar 08, 2010 7:16 am 
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If thats a measured value then its lower than gasoline according to the data posted here, so whats going on? Is it more or less viscose? I dont have any experience with E85 as its not been available here until just now and no one runs it that Ive come across yet.


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 Post Posted: Mon Mar 08, 2010 10:23 am 
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shrinker wrote:
Yes ethanol is more viscose but what is E85? The viscosity isnt always a simple extrapolation of 2 values. What Viscosity is E85?


That is a good point, however, it is my understanding that the viscosity of E85 at 27*C is right about 1.20-1.36 Centpoise (have seen a couple different numbers). You would think that with the 15% addition of gasoline viscosity would move the other direction, but that does not seem to be the case. I believe that this has to do with the small % water (up to 1%) and additives that are in the blend.

Do you have any information to the contrary?

Mark, I think you have your numbers mixed up ;) Looks like you are referring to 71*C numbers, not 27*C

PS. Also note that viscosity is NOT directly linked to density! This is a common misconception. While these two properties do often correlate it is not a rule. You cannot say that because ethanol is heavier than gasoline it is more viscous. It may be more viscous, but density is not why!


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 Post Posted: Mon Mar 08, 2010 12:56 pm 
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Eric68 wrote:
Mark, I think you have your numbers mixed up ;) Looks like you are referring to 71*C numbers, not 27*C

Eric, I believe your correct, it had been a long while since I did the math and you know how my memory works, if the sheets not here in front of me im lost....lol

thank you for clearing that up for me.


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 Post Posted: Mon Mar 08, 2010 4:12 pm 
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Firstly I cant find a reference to the viscosity of E85 and that would be because it would be different depending upon the Gasoline mix added anywhere in the world. So unless someone can show a correct viscosity test between 2 plates for a range of E85 fuel samples then how can you state that E85's viscosity is the reason for your differences in calibration? There must be more to it than that. In winter when it becomes E75 what is the viscosity then? what happens to the fuel calibration then? How does the winter blend gasoline affect the ethanol? If viscosity is the important factor then it would be very difficult to maintain consistency. How do you deal with E10? why do some carby cars like it and others don't? Is it solely the variations in viscosity and the emulsion of different OEM designs?
Also you make mention of the viscosity as the reason for the float 's flotation differences, however with respect, that is not correct. Its the density of the liquid that relates to the upward force of flotation of an object, according to the law, its the weight of the displaced liquid that equals the upward force.
Therefore your statement about the viscosity affecting the lifting force of the booster is also incorrect. The pressure reduction created by the booster will lift the E85 slightly lower than it does gasoline, that results in a slight delay of mains flow and a slight leaning of the mixture overall. That brings me to my next question.
You suggest a jetting difference from gasoline to E85 and Im sure you find that a workable suggestion, my question is, if you had equal lambda on E85 to the lambda of a gasoline tune, is the volume of fuel consumed equal to the jetting area and the density change or is it affected significantly by the viscosity. What I'm asking is when you have consumed a liter of gasoline in a measured time you have consumed a certain amount of energy based on time, that energy has passed through your engine, what you have achieved with it is variable depending upon the engine efficiency, but a lambda measurement is efficiency independent, so when you consume the same energy level with E85 does the jetting area change correspond to that? That is one way of indicating if the viscosity is significant in your reasoning. It's not an accurate viscosity test of course but it should indicate it's importance. I'm asking this because I would like to understand why you remove the emulsion bleeds for a liquid that you claim to be harder to move along a tube and yet e-bleeds have the purpose of making that easier.


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 Post Posted: Mon Mar 08, 2010 4:28 pm 
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Gawd I love this high tech stuff! =; Even though E85 isn't one of my priorities. If I can't run it, I really don't have a dog in this hunt!

You guys be civil now! \:D/ Let's see some more of this stuff that's WAY over my head, but I do enjoy the read and I do understand "some" of it! Dayum, I wish I was "smart"!

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 Post Posted: Mon Mar 08, 2010 6:37 pm 
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We are being civil aren't we Ken? I'm just wondering why the additional force of the air isn't being used by Mark to promote flow. Adding air via the e-bleeds lowers the density of the fuel thus increasing the flow volume at low pressure depressions and by balancing that to the main jet size and booster size the top end flow which would otherwise be enriched can be leaned. I realize there are ways to control the flow without air bleeding and these ways are bore sizes etc utilizing the viscosity to reduce flow caused by the boosters placement in the main venturi but that method is generally less adaptive, takes much more research to get right and is not adaptable for the customer. And then there is the added complexity of reliant upon the viscosity for the tuning and E85 varies too much to be reliable.
So I am interested in the difference in performance from the 2 approaches. I'm not concerned that Mark is critical of the calibration of the carburetor in question, that could be changed of course and possibly be better suited to the engine but why is he critical of the choice to use emulsion verses not? Surely if his technique was superior to e-bleeds on E85 then it would be so on gasoline etc. The physics doesn't change, just the values of components. To me a Booster style carby should be better with e-bleeds, it would be a more consistent carburetor for weather and fuel changes that are well documented for E blend fuels. When you use air you can control the density of the fuel in the main well to some extent and that is used to overcome the viscosity effect upon flow rates.


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 Post Posted: Mon Mar 08, 2010 7:32 pm 
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I hope you don't mind me jumping in again -- not on Mark's behalf, but because we tend to use the same approach and this is a good discussion.

Regarding viscosity, I think that this is far from being the only property that makes E85 different than gasoline. Besides the viscosity, the weight of the fuel per gallon is heavier by about 6%. So combine it being heavier with it having roughly twice the viscosity of gas and you have a fuel that does not want to move as easily as gas.

With fuel injection (as this fuel was really intended for) the computer can compensate for the different flow properties by using a different map. With the carb as you know (probably better than me!) we aren't so lucky. But we do have a couple tools at our disposal to use. Emulsion air is one (obviously) but there are other methods that work as well.

What I think that you are forgetting here is that the use of emulsion air to lift the fuel is a double edged sword. On one hand, it will help lift the fuel at the onset of the main circuit, but at the top end of the engine's RPM band it would tend to cause the circuit to lean out. In order to pull the curve flat I find that I prefer to use a smaller bleed, less emulsion air, and other means to get the fuel flowing down low.

Of course you could take a different approach to the problem by using a very sensitive booster to help pull more fuel at the top end of the fuel curve to compensate for the leaning effect of the emulsion air and large bleed, but I don't personally like that. Too easy to wind up with an "upside down U" shaped fuel curve that is lean in the mid-range. Of course I could always resort to using booster pullover for high RPM enrichment ;)

Thoughts?


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 Post Posted: Mon Mar 08, 2010 7:37 pm 
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shrinker wrote:
We are being civil aren't we Ken?


Yup shrinker, you all sure are and I and others appreciate that!!! That was just a reminder to all to, "respect" others points of view/opinions/experiences. Haven't read the "flame war" on ST and don't want to go there but, I do love a "spirited" debate as long as it involves, FACTS, ie, scientific data and or real world experience as on occasion stuff that works on paper doesn't work on a real car! And, I really like real world "A B" tests to back up theory. \:D/

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 Post Posted: Mon Mar 08, 2010 8:46 pm 
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Ken- No worries, that ST thread is terrible. One person on there seems to bash someone else almost religiously, Its not good and I dont do that. I havent had any experience with E85 as I said but I will some day and I want to know why there is this discrepancy in technique. My carby is different with no booster etc so its not for my benefit but just for my curiosity. The issues with viscosity will apply to my carbys though.

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.

Mark--- I guess you will have read all of this before getting to here, But I think that if you revisit emulsion and the relationships to main jet restriction you might improve some aspect of your carby. I it was me, I would be endeavoring to understand reasons why I am going against convention in order to better understand what I'm doing and therefore improve faster. I have found that through my life, every time Ive had a failure I have had to investigate why and furthered my understanding by doing that, then I have advanced far faster than previously.
One needs to constantly question even ones own self.


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 Post Posted: Mon Mar 08, 2010 9:25 pm 
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Shrinker, the point I think Mark and Eric are that the larger emulsion used in that carbs calibration was a crutch for the large mainwells and booster legs to get the fuel to start, but would be at the expense of being lean at the top. The air bleeds and emulsion bleeds are there to shape the fuel curve for the given carb, fuel, and engine that the carb is run on. Now you say emulsion is a good thing, but when is it too much and how do you add it on any given setup WITHOUT affecting the fuel curve adversely?


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 Post Posted: Mon Mar 08, 2010 11:16 pm 
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all i know is what works and what dont, and sometimes the why..I cannot get into a technical debate as I simply cannot answer in those terms.

and maybe i was using some wrong terms, but I knew what I was saying... :-

I tried and had a technical post that took 2 hours to put together and i lost it...

so heres the short of it....that anyone should be able to understand.

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,)

the calibration I listed had the fuel flowing slow/lean (mainwell size), then fast/fat (high rpm mainwell size), thick (larger jets/low velocity), then lean (huge emulsions and high rpm velocity),

im sure im going to screw this up, but try to get what im saying......
E85 is LIQUID LIQUID GAS = Ethanol, gasoline, air....extra emulsion air introduced tends to stur things up and disrupts the flow of the fuel and the way it reacts within the carburetors channels..
regular fuel is = LIQUID GAS = Gasoline and Air.......it dont care if you add more air....it just leans the mix.

the velocity and fuel consistancy was all over the place with the posted calibration....wrong for E85.
E85 likes a nice steady movement and does not like alot of emulsions inturupting the flow of things.

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.

which is what E85 likes.


Maple syrup:
carefully pour your maple syrup on your hotcakes, nice and thick and stays right where you want it, on the cakes.
now before you do anything, look at the syrup level on the bottle and note it....
shake it up until it has 10,000 bubbles in it and look at the syrup level again....
its higher because the syrup is emulsified...
now hand it to your buddy....
it pours alot faster and goes all over his cakes and onto his plate....

now look at your cakes vs your buddys....

your syrup is still where you want it....his has ran off the sides and soaking the bottom.

E85 likes density, denser the fuel through the boosters, the more power you can make....
(now I didnt say a rich mix, just a denser mix.)

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...

maybe thats why as rookie carb builders Eric and I are doing as well as we are, because we dont know where the conventional carburetor box is so were always thinking outside it......lol.

Tuner told me to find the extreme and go there then work my way back.....I did this on nearly every single aspect of my carb calibrations, I moved both directions until I found what works best.

and large over emulsified mainwells are NOT the answer, neither is micro non emulsified mainwells....been there, did them both....and I have found the flat fuel curve that maintains an even fuel velocity relative to flow.

I believe thats why my stuff picks up ET and theirs get sent to me for repairs....lol =D>


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 Post Posted: Mon Mar 08, 2010 11:36 pm 
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Eric68 wrote:
What's up with Viton N&S and E85 Mark? Been using Viton tipped N&S with E85 for a few years now with no issues here . . . in fact I like it better than stainless. It seems to seal better for me. I guess it depends on what fuel pressure you use too.



Eric and I discussed this briefly today,
and we (mostly eric) somewhat concluded that with the standard holley floats that Eric is using it doesnt have the leverage to shut off the stainless N&S so he uses the Viton tip.
I use Braswell floats and I believe the leverage is slightly better and has enough lift to close the stainless N&S while smashing the Viton tip....lol

so I guess you can use either N&S you want, just make sure its the stainless with the braswell float (right doug?).....lol

Eric, as soon as Braswell gets my float shipment ready Ill send you a pair to try ....your going to like them, I think the shape allows for a different boyancy and lets the N&S move deeper allowing more fuel under full load while maintaining our float level height at idle.

the holley stuff is cheaper, but the quality gained in the braswell float is worth the extra coin spent....might be something to consider?


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