Weber jets??All who live for their triples please read this

[duragg]

32mm chokes

140 main

165 air

 

Are you sure about the Air Corrector?

Just for grins, I would pull all of them and verify what you have.

Typically the AIR is 40-50 higher than the Main.

 

Its good to check them all and re-seat as we did at your garage and clean them again anyways.

 

Fuel jet adds fuel:  aka:  "Quantity"

Air jet adds air.       aka: "Quantity"

They mix in the emulsion tube.   aka:  "Quality"

 

How exactly they mix inside the emulsion tube and at what rate, early , late, fast, slow, big, small is all the mystery of the Emulsion tubes.  There is extensive discussion of this on Yahoo Group:  Sidedraft Central.  Including one person who is making / made new Emulsion Tubes. 

 

Pandorra got out, eh?

[AZGhost623]

Still waiting on the moderator to approve me on that Yahoo forum. Im eager to get it checked out.

 

I asked the same thing on the airs to have a 200 size, to make sure he wasnt mistaken on the air. He said that is typical rule of thumb to go +60 up from the main to the air size, but he is going based off personal experience over his years and what he thinks may make a good street tune. Once you get into compression, and other mods it really comes down to experience he said. Not that he is very experienced with the Z, but he has raced against them he mentioned, and knew of their setups. It doesnt cost me anything, so why not, its just my labor.=) I would be singing a different tune if I had to pay for it now.

 

I verified the sizes when I pulled them all out last time. 

Edited April 2, 2013 by AZGhost623

[Lazeum]

Your car is making weird noises on the video

Your idle & progression seems off, idle jet could help but the only way to tell would be to give it a try

 

Leon,

While I'm following on Sidedraft central discussion about gravity e-tube with a lot of interest, I've never had to complain about my carbs. They work flawlessly with immediate action. I'm running F11 tubes with no issue at all. People run for decades DCOE with great success so I'm a little bit biased. I don't doubt about Keith results but the improvement, as far as I'm concerned, would be marginal. I'd rather focus on ignition as we've done it both with Megajolt.

Edited April 2, 2013 by Lazeum

[Leon]

FWIW, my current jetting in my stock-cammed L24 is:

 

30mm chokes

O3 e-tube

H221 hypojets (similar to 55Fx idle jets)

120 mains

100 airs (not a typo)

50 pump with zero bleed

 

Idle is 14.5:1, transition and cruise is a bit rich at 13:1 (should be solved by leaner idle jet) and WOT is a bit rich at 12:1. The current plan is to downsize the idles to lean out my cruise mixture (~15:1) and play with mains to get WOT right (~13.5:1). I may also play with e-tubes/pump jets if necessary to get throttle response "perfectly" dialed in. Keith's scientific approach to all of this makes so much more sense and works way better than the black-magic, voodoo approach that is typical with carbs...

 

Matt,

I don't doubt that you can get them to run without complaining, but different people have different expectations. I want immediate, ITB-like response in any situation, whether I floor it at 1200rpm in first or while cruising on the freeway in top gear. I also want as best fuel mileage as I can get. That's the beauty in fine-tuning these things and using Keith's parts, I can dial them in more easily and more precisely (and cheaper in the long run as far as I see it).

[Lazeum]

If Keith suceeds with immediate throttle response at 1200 as well as 5000rpm. Allow us to run the engine at WOT around 12.5 without breaking the bank (= not much more expensive than "official" parts) I'm going to be Keith customer soon.

He seems to achieve quite good results so far.

[Leon]

If Keith suceeds with immediate throttle response at 1200 as well as 5000rpm. Allow us to run the engine at WOT around 12.5 without breaking the bank (= not much more expensive than "official" parts) I'm going to be Keith customer soon.

He seems to achieve quite good results so far.

 

Well, I've already achieved your first sentence.

 

At this point, I'm going after the finer details. The driveability is great, I'm just chasing the last few HP and MPG.

 

The thing is, his parts cost more up front but save you from buying 3X more jets if you're testing on your own with "official" parts. It helps that he's local to me too. I only know of 2 Z guys running his jets (myself and Rob from CZC) so there's no "proven" setup yet. We're basically the test dummies, but it sure is a lot of fun!

[Lazeum]

Being local surely helps! I would be part of the game if I was living next to Keith also. It's definitely rewarding to get good running carbs.

You're basically on the other side of the planet, it does not help to play trials & error... :/

[Leon]

Being local surely helps! I would be part of the game if I was living next to Keith also. It's definitely rewarding to get good running carbs.

You're basically on the other side of the planet, it does not help to play trials & error... :/

 

I'll keep you up to date then!

[Lazeum]

Thanks! I'm also on Sidedraft central but it would be very interesting to get feedback from you & your L28.

[AZGhost623]

So... I made significant progress by just changing out the chokes to 32. I think i didnt need to go that low, but the car will now do a burn out in 1st, and chirp without any problem into 2nd. The AFR is dead on at 12.5, and when I had it up around high rpm (5500 ish) (this is a new build Im not ready to take it all the way yet), AFR was between 17 and 18, the good thing now is the AFR gauge does not lean out at all. So I assume I can get a slightly bigger Main, and be ok. Transition rocks... I did notice a very tiny blip at one point but I was feeling/listening for everything that I forgot to realize what I was doing. I suspect it might have been timing with the aftermarket ignition...  But it was very minor, and it seemed like it might have been more high rpm than transition. So with it drivable now, I have something very good to work from and build on. I would like to get back up to 36 chokes, but Im going to need a lot more fuel being added, but this whole process has been a lesson thats going to continue for a while. 

 

So my setup as it stands now. I want to increase the main jet and Im more than likely going to move to a F9 size idle jet. I have a small collection of growing parts now... but I was grinning for ear to ear after my around the block trip. These are on DCOE 152's.

 

32 choke 

145 mains

155 airs

55F8 idles

F16 Tubes

00 Pump Bleeds

45 Pump Jets

Edited April 10, 2013 by AZGhost623

[Lazeum]

If you can record some pulls with your wideband you'll see more info than just looking at your gauge. You will be able to see what could be improved.

When I fine tune my carbs, I'm not looking at my AFR anymore. It becomes feeling. This is only when I'm undecided between 2 jets.

 

It seems too small venturi will create a rich mixture at high rpm due to lack of air since venturi are not able to keep up. Check it with your setup, you might be able to tell. Going from 36mm to 32mm is a huge step.

Edited April 10, 2013 by Lazeum

[duragg]

Nice work. You got the 32 chokes for cheap or free right?

Anything north of 14 is exceedingly lean (LOP) for full power.

Try your next bigger main jet and clean them all again while at it.

 

I might need to borrow your 36 chokes... take them to work with you today?

Else I could find you tonight.

[AZGhost623]

Chokes were free, he just gave em to me as they were too small for him. I see a 2 stage approach right now. Im going to increase jet sizes on these 32's since Im leaning out now on top end, and once I get that fixed, Ill move up to a 34. Ill use the AFR and of course the butt dyno I think a gradual approach will help me better try and find my way than just changing everything. Knowing what works before hand and how the car performs I think is key before moving forward. Its a more expensive approach but I understand it better. Its really helped me understand things now that I have gotten the car to work and playing with different jet sizes, and ultimately the chokes. After contemplating it, I want to settle on a 34 choke size, as I feel that will be more the right setup with this car for now. I could probably get the 36 to work, but my idle jet it too small to handle the transition I know for sure and then jet sizes need to be increased too. I need to get my tail lights all hooked up so I can get it on the freeway and play more.

 

To Lazeums question, I dont think its getting rich. The AFR gauge doesnt go off the chart anymore even when im doing some heavy pedal it goes lean. Really upset that TopEndPerformance.com didnt set these carbs up like I asked and they just sold me a factory kit. I specifically asked them to do that... and im pretty sure i burned that bridge too now. oh well, atleast im learning a lot from people who do care.

 

Duragg I can get you the 36's.... They are at home right now. I can give them to a common friend of ours here at work, or I can meet you somewhere for lunch one day this week if you want. What you thinking your 40's are too big now? 

Edited April 10, 2013 by AZGhost623

[duragg]

 

Duragg I can get you the 36's.... They are at home right now. I can give them to a common friend of ours here at work, or I can meet you somewhere for lunch one day this week if you want. What you thinking your 40's are too big now? 

 

Just as a backup plan if I cannot swing the 40s, I will have something more reasonable since I don't have a lot of time before Saturday.    I am going to see how things work tonight, hopefully I can at least get it running and work on dialing in the next few days.

 

I have been assured by Rebello that with my cam, engine and other specs they will work swimmingly and if they don't it is purely a result of my lack of manly fortitude. 

 

Fair enough I guess.

 

TJ

[AZGhost623]

Duragg, its bugging me a lot, and I need to know why now...

 

Why the F11's emulsion tubes? Everything I have been researching on says that based off our per cylinder cc on our engine size, you should be running atleast an F16 like me... we are right in the middle between an F16 and F2. Did Dave at Robello give you any other info on why F11?  Some kind of secret sauce Dave has found ? See what happens when I become some what educated, I start demanding answers! =) This is in the weber book, granted its just a suggestion as well.

 

Cylinder Capacity     suggested emulsion tube

250-325                      F11

275-400                      F15

350-475                      F9,F16

450-575                      F2

 

 

Emulsion tube tables:

http://i217.photobucket.com/albums/cc281/B20Paul/WeberEmulsionTubes1.jpg

http://i217.photobucket.com/albums/cc281/B20Paul/WeberEmulsionTubes2.jpg

[duragg]

I tried F16 years ago and could never make them work so I went back to my F11.

My new DCOE45s came with F16 and so now I have a dozen useless F16s.

 

More than just qualtity of fuel and air mixed into emulsion is the quality and method by which they combine. 
I found from my own research years past the F11 worked *For Me*.

 

When I setup these 45s tonight the first thing I did was shitcan the stock jet loading from Weber and switched to the stuff Rebello had sent.

Pushed the button and Vroom,.. started right up and made great pulls. 

I need one bigger idle and one smaller main and I will be 95% done.

 

This is a FAR FAR cry in ease of setup with these new 45s from the last 10 YEARS I spent ******* around with the DCOE40-151 which required extensive modification to make them run almost as well as these new 45-152s did on the first day running.

Edited April 11, 2013 by duragg

[duragg]

Perhaps we should think of the work of an Emulsion Tube more along the lines of a chef or expert baker mixing fat, egg and air to make a terrific pastry.

The skill and mastery of the chef is far more critical than the individual ratios.  A great chef can make an amazing cake from a wide variety of proportions.

And so a superior emulsion tube for a particular engine could have generally better performance than another (which may be superior on some other intake system).

 

Or...

Why one smart switch works better in one network than another, even though it is mixing the same stream of data. Nobody really knows.

I'm staying F11.

[AZGhost623]

heh... it might just be yours years of experience working with these carbs to know whats going on. It all makes sense to me now, and I hope to have mine fixed here soon as those new jets come in. As far as the emulsion tube goes, isnt F11 smaller than F16? I get what your saying, but just doesnt make sense to me... to each their own I guess. I didnt order any F11's, staying with the F16's.

[Leon]

I'm sensing confusion and uncertainty of what the e-tube does. It's not voodoo, but it is somewhat complex and it seems almost nobody understands it. Here's my interpretation, basically what I've learned from Keith's research. It may help to have a tube in hand, or even better, a cutaway drawing open.

 

First, why is the emulsion tube even needed? Liquid gasoline has non-negligible viscosity. If we plug off the air-supply to the main circuit, the engine will run leaner at low speed and richer at high speed. This is because at low speed, the lifting force from engine vacuum is not strong enough to pull up enough of that viscous fuel. At high speed, the effects of fuel viscosity are lessened (higher vac signal) thus too much fuel gets pulled in. Now, if we introduce air into this fuel column, this effectively makes it less viscous. At low speeds, the air helps to draw in more fuel even though the vacuum signal is "weak". At high speeds, where viscosity matters less, the air dilutes the fuel and thus slows down liquid fuel flow-rate. This helps the carburetor to achieve a flat fueling curve. My explanation may be a bit simplistic but this is why these carburetors use emulsion tubes!

 

The e-tube controls the fuel-metering of the main circuit. It does so in two ways, (1) outside diameter, or impedance as Keith termed it, and (2) hole size and location. The main circuit draws in fuel from the float chamber via the "main" (wet) jet and that fuel mixes with air drawn in through the "air corrector" (dry) jet. The e-tube gets its air supply from the dry jet which sends air to the inside of the tube. In order to reach the venturi, fuel must flow up between the e-tube and e-tube well. This is where the air mixes with the fuel via the small radially-located holes on the e-tube and continues towards the venturi (in two-phase flow).

 

Here's the important bit, the radial holes in the e-tube must be below the fuel (float) level! All a bleed hole above the fuel level does is diminish the vacuum signal to the main circuit. While this may be OK for high-speed operation, it's absolutely terrible for low-speed. Once you understand this, it's no wonder why so many people have low-RPM bogging issues...

 

As Keith discovered (as well as I can remember), pretty much all of the Weber F-series tubes were designed for their down-draft carbs, which have different fuel levels and well dimensions! As it turns out, pretty much all of these F-series tubes are terrible for sidedrafts. Keith did find one F-series tube that would work OK, that being the F7 but it's necessary to play with plugging holes in order to obtain proper performance. It also lacks enough impedance to provide optimal gas mileage (impedance plays a role in mid/high RPM part-throttle operation, not so much at WOT).

 

This is just what I've gleaned by following Keith's work, all the proper details are in the Sidedraft message board. I'm not trying to advertise for him and am not benefitting from this in any way. However, this is exactly the reason why I decided to ditch the Weber stuff and go for Keith's jetting (custom e-tubes and adjustable idle jets). Like I mentioned in previous posts, I don't get any bogging anywhere and I also get better gas mileage to boot.

[AZGhost623]

Well I knew what the emulsion tubes did, but not to that kind of level so thanks for the lesson Keiths stuff is expensive, and I dont get how certain things match up to the weber counterpart.... I like the idea of some of the things he has put together, but at $20+ a jet that adds up real quick.