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#2466129 - 03/13/18 10:09 PM Re: holley billet metering block and emulsion jet question [Re: dartman366]
hemi-itis Offline
I Live Here

Registered: 12/29/07
Posts: 10528
Loc: Great Neck,LI,new york
We need a "like" & "LOL" button!! shruggy
_________________________
HEMI-ITIS has no cure. My condition is fully BLOWN!!!

New best 60ft,, 1.42,1/8, 6.0 @117,, 9.38 @146.75 with 6 lbs boost @3700 lbs

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#2466146 - 03/13/18 10:34 PM Re: holley billet metering block and emulsion jet question [Re: dartman366]
Mattax Offline
super stock

Registered: 02/28/10
Posts: 1105
Loc: Phila. Pa.
There's lots of ways to prevent or correct a misunderstanding. Let's see what happens.

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#2466147 - 03/13/18 10:36 PM Re: holley billet metering block and emulsion jet question [Re: dartman366]
max_maniac Offline
master

Registered: 01/20/03
Posts: 6114
Loc: Aurora, Oh.
Originally Posted By dartman366
Originally Posted By G-Money1320
Bill ,you are definitely in good hands with Dom. as I am patiently waiting for my new carb to show up from him!! Lots of phone time and more knowledge than I ever knew existed about carbs!!
I believe you are correct but I wish the phone connection was better and I didn't have to make him repeat so many times, don't know what was going on there. shruggy




Bill if you would finally get rid of the can/line phone you may get a better connection --- haha haha panic
_________________________


63 Dodge Max Wedge NSS
64 Dodge now with a Hemi
64 Dodge wagon coming soon!

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#2466178 - 03/13/18 11:53 PM Re: holley billet metering block and emulsion jet question [Re: dartman366]
Mark Whitener Offline


Registered: 12/05/14
Posts: 275
Loc: Florida
Well lets see if I can prove Andy wrong here.

You have to understand the reason for an emulsion system. Take your C&S Aerosol billet carbs, they do not us a booster, they use a discharge tube. There is no emulsion used, save for a very small main air bleed and one bleed above float level to act as a kill bleed. A tube senses airflow at a one to one ratio as the pressure difference or vacuum increases, so fuel flows in a direct proportion to the airflow thru the carb, so only a main jet is needed to set the correct amount of fuel. A booster however does not flow one to one, it flows in a straight line as pressure difference or vacuum increases, however the airflow curves towards a horizontal flatline.
As a result an air correction system, emulsion, is needed to allow the booster signal to follow airflow. And it is there mostly for air correction, emulsion or emulsified fuel is a result of the air correction, and should not be relied on to emulsify the fuel. This is where some carbs go off the deep end.

The second part of the air correction/emulsion passage on a standard Holley 4 barrel is that it holds fuel, so as air is pushed from the main air bleed down the well the fuel is pushed out of the emulsion bleeds, making it an added acceleration circuit. Remember this.

So what happens is as the signal becomes strong enough to start fuel flow it also tugs on the emulsion passage. Any bleed above fuel level will delay the start, and will depend on the total area of the bleed or bleeds and the size of the main air bleed. This is where bigger and smaller main air bleeds can delay or speed up a little the start. However once the fuel flow starts the large bleed can actually fatten it quicker, allowing the fuel in the emulsion well to be pulled faster into the mainwell. This can make it excessively rich early with a larger bleed, and combined with a lot of emulsion goes off the deep end. Then as RPM's and demand climbed it shoots the other way, goes lean. I see this when more than 3 bleeds and over .028" emulsions, and over .030 main air bleeds. What also happens is the air goes thru in big slugs making the fuel curve choppy, fuel is not mixed well with the air coming into the mainwell. It leaves the booster in spurts rather than an even mix. Once the fuel is depleted to the bottom open emulsion hole then it just feeds air, until the throttle is closed and the mains stop, and the emulsion well is allowed to fill again.

So what do you want to accomplish? It depends on the application, fuel type, engine demands... What I find is when you use a booster that atomizes fuel well to distribute fuel evenly you don't need any more air than what is needed for correction. For most gas carbs on the street a kill bleed and two .026-.028 holes spaced to go about half way down the well is plenty. I like smaller bleed for racing, and usually space three smaller bleeds. And if I can control the kill bleed size even better. With alcohols and oxygenated fuels, or big engines with two carbs you can place the bottom bleed all the way down, use all the fuel emulsion well. I set most race carbs up this way, but with a small bleed usually at .021 or smaller. I have a blow thru I reworking that will likely get a .021 at the top for a kill, .024 all the way at the bottom. And a last piece of this puzzle to remember is that at WOT the idle circuit that usually pulls from the bottom of the mainwell can now become a bleed into the main circuit, adding more air in....

Now with E85 you have a significantly different fuel in the mix. Too much air makes it stupid rich early, lean at the top. I've seen it chased on a dyno... once emulsion was set small it cleared things up. For E85 go real small, I've got an RS Demon that has .014 in the top, .016 third and .018 forth with the second and fifth plugged. For the Dominator get the top small, .014-.016, and .020-.021's in the third and fourth or third and fifth on 5 hole blocks.
_________________________
Mark Whitener http://racingfuelsystems.myfunforum.org

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#2466179 - 03/13/18 11:56 PM Re: holley billet metering block and emulsion jet question [Re: max_maniac]
MR_P_BODY Offline
Master

Registered: 06/13/03
Posts: 50739
Loc: Romeo MI
I meet a few of the Holley engineers in meetings
when I worked in the carb lab(wish I worked in
that area longer) but even they would argue in
some of those meetings.. I dont know what all
the argument is about but Andy stated his opinion..
I have have gotten good info from both guys and
thanks to both
EDIT
also guys.. remember.. cars are nothing but MATH
and its ALL math.. we dont just think up this stuff
wave


Edited by MR_P_BODY (03/14/18 12:52 AM)
_________________________

W-9 8.94 @ 151 NOW ON E-85
Mike "Raff"...(180)Watching over us
CAR IS FOR SALE

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#2466190 - 03/14/18 12:32 AM Re: holley billet metering block and emulsion jet question [Re: dartman366]
RustyM Offline
enthusiast

Registered: 02/24/17
Posts: 215
Loc: Texas
After being out of this for 30 years , everyday is an adventure in learning .

Fwiw: In other fields I have spent enormous amounts of time on forums, in study groups/ social media groups.
Most of these have a limited useful lifespan and then start disintegrating before generally coming to death .
It seems Moparts has been around a good while - much longer than most formats of this type .
Personalities here “ self manage “ much better than most, including upper end academic groups.
I might also comment on the grace / help shown to new people - extreamly friendly and helpful.

In my opinion - this is a rare place/ combination today and it is that way because of the quality of the people here.
No- I’m not blowing wind up your dresses - just seen a lot - it’s an honest assessment .

I haven’t physically met anyone yet but have talked by phone, e-mailed, messaged and done some financial/ goods transactions - all of which have been as they should be.
I know I can ask questions and get not only help, but options to consider.

I appreciate this place and the people that make it what it is.

One thing that’s both good and rather sad:
I can get better information/ data here than I can from The company’s we all purchase from.
Example : One can get much better data on Trick flow heads here than one can from Trick flow.
Another: One can get much better information/ data here than one can from Holley.
I won’t mention Indy much.

Thought the other day- need sticker: Designed by Moparts

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#2466425 - 03/14/18 01:46 PM Re: holley billet metering block and emulsion jet question [Re: Mark Whitener]
cudadon Offline
top fuel

Registered: 11/24/03
Posts: 2109
Loc: New Lenox IL
Thanks Mark!

Don

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#2466439 - 03/14/18 02:00 PM Re: holley billet metering block and emulsion jet question [Re: cudadon]
Thumperdart Offline


Registered: 07/12/04
Posts: 18691
Loc: State of confusion
Originally Posted By cudadon
Thanks Mark!

Don


Mark W is a wealth of info for sure and has opened my eyes up to the many tuning scenarios involved in these carby thingies........... thumbs
_________________________
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB for videos and lots of carb pics......760-900-3895.....

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#2466582 - 03/14/18 06:23 PM Re: holley billet metering block and emulsion jet question [Re: Mark Whitener]
jbc426 Offline
master

Registered: 03/01/07
Posts: 2726
Loc: West Coast, USA
I was getting ready to increase the size of the fuel restrictor in my metering Promax billet metering block based on a lean wideband reading I was getting at idle. This is on the old Direct Connection 2300 series "racing" carbs with the mechanical outboards that have no idle circuits and blocked power valve holes in the metering blocks. I love these carbs and have been running them for years.

I was thinking that I had enough of an understanding of emulsion circuits and metering blocks to do what I was about to do. Heck, I was able to adjust the main jets using a wide band, so I thought I would just increase the main restiction jet 3 sizes from .031" to .034" and recheck the A/F ratio. I figured it would be richer at idle afterwards. After all, I had been getting readings of 22 & 24 to 1 before the gauge zero out due to leaness at idle. More fuel should work like increasing a main jet at cruise and wide open throttle I thought. It might have.

I knew I had too much of the idle transfer slot uncovered from watching Youtube videos on Holleys. I tried opening the outboard carbs throttle blades very slightly to simulate drilling holes in the center carb throttle plates. As I closed the center carb's throttle blades using the idle screw, a surprising thing began to happen. After a few minutes, I had the center carb closed up significantly, and the outboard carbs open about a half a turn of their idle screw from fully shut.

To my surprise, the A/F ratio was now in the mid to low 15's at 900 rpm. The idle is much more stable and the response off idle is as good or better than it ever has been.

I expected that bypassing more air through the outboards would have leaned out the A/F ratio even more than it had been. It actually richened it up and the car is running better than ever now. Can anyone clarify the physics behind that?

On a side note, I have C&S building me a set of aerosol 500 cfm mechanical carbs using the body of a spare outboard I found on Ebay. I'm looking forward to a back to back chassis dyno test to see if they build more power.
_________________________
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 3.73s
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3600 stall lock-up converter and 3.91's (closest thing to an automatic 5 speed going)

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#2466604 - 03/14/18 07:03 PM Re: holley billet metering block and emulsion jet question [Re: dartman366]
ccdave Offline
The Ultimate

Registered: 01/22/03
Posts: 1737
Loc: Mopar Country, Mi
All I know is not to use those springs with that rocker.

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#2466621 - 03/14/18 08:02 PM Re: holley billet metering block and emulsion jet question [Re: max_maniac]
dartman366 Offline


Registered: 01/18/04
Posts: 13093
Loc: Mt. Vernon, Ohio
Originally Posted By max_maniac
Originally Posted By dartman366
Originally Posted By G-Money1320
Bill ,you are definitely in good hands with Dom. as I am patiently waiting for my new carb to show up from him!! Lots of phone time and more knowledge than I ever knew existed about carbs!!
I believe you are correct but I wish the phone connection was better and I didn't have to make him repeat so many times, don't know what was going on there. shruggy




Bill if you would finally get rid of the can/line phone you may get a better connection --- haha haha panic
time to up grade to a better string, but it still beats smoke signals. tonguue
_________________________
Light travels faster than the speed of sound,,,this is why some people seem bright untill you hear them speak.

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#2466629 - 03/14/18 08:20 PM Re: holley billet metering block and emulsion jet question [Re: jbc426]
Mattax Offline
super stock

Registered: 02/28/10
Posts: 1105
Loc: Phila. Pa.
Quote:
I expected that bypassing more air through the outboards would have leaned out the A/F ratio even more than it had been. It actually richened it up and the car is running better than ever now. Can anyone clarify the physics behind that?
I'll give it a shot.

Originally Posted By jbc426
.... After a few minutes, I had the center carb closed up significantly, and the outboard carbs open about a half a turn of their idle screw from fully shut.

It seems like you balanced it. The engine consumes about the same amount of air - at least by volume. The total restriction to air flow is similar or little more than it was before. Enough so that the vacuum at the idle discharge areas is noticible higher than before.
This increase in pressure difference is moving more fuel through the idle circuits. This more than offset any drop in the air mass flow density.

Even at the lower throttle position, it seems likely in this case that the idle jets are still the main restriction on fuel at idle.

I'm curious, are the idle jets on this carb located below the fuel level?


Edited by Mattax (03/14/18 08:25 PM)
Edit Reason: clarity, I hope!

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#2466651 - 03/14/18 08:58 PM Re: holley billet metering block and emulsion jet question [Re: Mark Whitener]
sgcuda Offline
master

Registered: 01/28/05
Posts: 3845
Loc: Charlotte, North Carolina
Wow! Thanks, Mark. That is a very quick, fact filled explanation of the carb circuits. Very inspiring.

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#2466738 - 03/14/18 11:37 PM Re: holley billet metering block and emulsion jet question [Re: Mattax]
jbc426 Offline
master

Registered: 03/01/07
Posts: 2726
Loc: West Coast, USA
Yes, I believe they are, but I'll have to double check.

Thanks for the insight.
_________________________
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 3.73s
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3600 stall lock-up converter and 3.91's (closest thing to an automatic 5 speed going)

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#2466827 - 03/15/18 09:02 AM Re: holley billet metering block and emulsion jet question [Re: jbc426]
Mattax Offline
super stock

Registered: 02/28/10
Posts: 1105
Loc: Phila. Pa.
Originally Posted By jbc426
Yes, I believe they are, but I'll have to double check.

I was thinking about this. If the fluid was exactly the same we could compare areas of the discharge restrictions with the feed restriction. But that's not the case, even with the high position, additional air and pressure comes in at the top of the transfer slot.

Low position should be more consistant, so not encouraging a change to high.* Just curious as I was thinking about this.
*Summary and background of why low position is almost always better for us is posted here: Idle Jet Position

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#2466889 - 03/15/18 11:34 AM Re: holley billet metering block and emulsion jet question [Re: Mattax]
jbc426 Offline
master

Registered: 03/01/07
Posts: 2726
Loc: West Coast, USA
Thanks, that is good stuff. I just found that site as a result of this post.
_________________________
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 3.73s
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3600 stall lock-up converter and 3.91's (closest thing to an automatic 5 speed going)

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#2467885 - 03/17/18 08:23 PM Re: holley billet metering block and emulsion jet question [Re: jbc426]
dartman366 Offline


Registered: 01/18/04
Posts: 13093
Loc: Mt. Vernon, Ohio
well It's all together and ready to put on the motor and try it,,,if it's warm enough to open the doors of the garage, this was a little more involved than I expected, I just don't know how Thumper gets them done as quick as he does, and if it weren't for him I would still be scratchin' my head trying to figure it out. luck
_________________________
Light travels faster than the speed of sound,,,this is why some people seem bright untill you hear them speak.

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#2468024 - 03/18/18 08:55 AM Re: holley billet metering block and emulsion jet question [Re: dartman366]
mopar dave Offline
master

Registered: 01/04/07
Posts: 5716
Loc: flint michigan
Those Dominators are very complex. You change one thing and it also changes something else. Constantly chasing your tail trying to nail down the street tune. Glad i have Doms number.

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#2468111 - 03/18/18 12:33 PM Re: holley billet metering block and emulsion jet question [Re: dartman366]
Thumperdart Offline


Registered: 07/12/04
Posts: 18691
Loc: State of confusion
It's taken me years, many spark plugs, oil, fuel and wear n tear to finally get a grasp on this carby stuff and still learning every day but it's FINALLY paying off and I'm glad I could help you guys out........... beer
_________________________
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB for videos and lots of carb pics......760-900-3895.....

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#2468237 - 03/18/18 05:15 PM Re: holley billet metering block and emulsion jet question [Re: Thumperdart]
dartman366 Offline


Registered: 01/18/04
Posts: 13093
Loc: Mt. Vernon, Ohio
Well,, it's on the car and running,,,and quite well I might add, once I got the float level set which was a little high and started to work with the curb idle screw's it came around quite nicely and sounds a lot crisper, idle tip in is smooth and there is no more blubbering like the other one(which I think I found the problem there) just smooth as silk up to the point the boosters took over, the other one sounded like it was loaded up a little and then would clean up so that is a big plus,, got it up to running temp for a while then shut it off,, let it sit for about 10 minutes and reached in and hit the start button and it was running and never touched the pedal,,,now for the tracks to open and start to dial this thing in. up and also a big thank you to Dom for bailing me out with good straight forward no BS answers and tech advise. up up
_________________________
Light travels faster than the speed of sound,,,this is why some people seem bright untill you hear them speak.

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