Weber 32 ADFA Float/Jetting Specs

[kkemerait]

Hi,

I could use the correct float adjustment specs for a Weber 32 ADFA on a 78 124 spider and also, if anyone knows, what were the factory stock jets on that same carb?

[bradartigue]

1975-76:

Main Jet 1.25 main 1.4 secondary
Idle Jet 0.50 main 0.60 secondary
Emulsion tube F74 main F74 secondary
Air corrector 1.85 main 1.7 secondary
Pump jet .5
Needle Valve 1.75
Float level 6.5 +/- .25
Primary Choke position at Full Throttle 1.05 main 1.15 secondary

1977-78:

Main Jet 1.25 main 1.4 secondary
Idle Jet 0.50 main 0.60 secondary
Emulsion tube F73 main F7 secondary
Air corrector 1.85 main 1.7 secondary
Pump jet .5
Needle Valve 1.75
Float level 6.5
Primary Choke position at Full Throttle 1.05 main 1.15 secondary

[kkemerait]

Brad,

Thanks!

[opus10583]

Hi Brad,

What are the functional effects of the Emulsion Tubes distinctions?

Thanks,
Mark

1975-76:

Main Jet 1.25 main 1.4 secondary
Idle Jet 0.50 main 0.60 secondary
Emulsion tube F74 main F74 secondary
Air corrector 1.85 main 1.7 secondary
Pump jet .5
Needle Valve 1.75
Float level 6.5 +/- .25
Primary Choke position at Full Throttle 1.05 main 1.15 secondary

1977-78:

Main Jet 1.25 main 1.4 secondary
Idle Jet 0.50 main 0.60 secondary
Emulsion tube F73 main F7 secondary
Air corrector 1.85 main 1.7 secondary
Pump jet .5
Needle Valve 1.75
Float level 6.5
Primary Choke position at Full Throttle 1.05 main 1.15 secondary

[bradartigue]

Emulsion tubes are one of the world's great mysteries.

This is a pretty good thread on them, from a Porsche forum, with some Weber tuning pages scanned in.

http://forums.pelicanparts.com/porsche- ... tubes.html

[opus10583]

We can assume the distinction is due to emissions concerns, does anyone have experience re-fitting a 77-78 with the earlier emulsion tubes?

[manoa matt]

As Brad stated, the emulsion tubes are a GREAT mystery. There is no sequencing to the numbers as a F7 and F8 are not one step from each other, the numbers don't go in sequence. Also a F7 for a 32ADFA is not the same as a F7 for a 32/36DFEV despite the carbs are somewhat "similar"

It's highly unlikely someone has the experience with mixing emulsion tubes between carbs, if anyone it would probably be Brad. The emulsion tubes set up from the factory can/should work for a limited range of main jets and air correctors.

[majicwrench]

Should be no reason to mess with the tubes. The people that put the carb together in the first place are darn good at what they do, and they have designed it all to work together. All engines are basicly the same, and take basicly the same mixture. Carb are designed to mix however much air is flowing thru them with the proper amount of fuel. For the vast majority of us, sticking with the stock jets etc is a very wise thing to do.
Keith

[opus10583]

Does anyone have photographs of the three emulsion tubes specced in the various 32 ADFA applications: F7, F73 & F74?

[opus10583]

Should be no reason to mess with the tubes. The people that put the carb together in the first place are darn good at what they do, and they have designed it all to work together. All engines are basicly the same, and take basicly the same mixture. Carb are designed to mix however much air is flowing thru them with the proper amount of fuel. For the vast majority of us, sticking with the stock jets etc is a very wise thing to do.
Keith

...

What FIAT was doing in the US in the mid to late '70s was furtively gerry-rigging its engines and carbs to pass the increasingly rigid US emissions laws in the dark days before digital engine management systems. The result of this was turning a sweet, sharp 116hp engine into a wheezing 87hp eunuch. If I can claw back some sharpness and drivability and power, and mellifluence by twisting the distributor and swapping $30 worth of carb parts I am more than willing to try.

[opus10583]

As Brad stated, the emulsion tubes are a GREAT mystery. There is no sequencing to the numbers as a F7 and F8 are not one step from each other, the numbers don't go in sequence. Also a F7 for a 32ADFA is not the same as a F7 for a 32/36DFEV despite the carbs are somewhat "similar"

It's highly unlikely someone has the experience with mixing emulsion tubes between carbs, if anyone it would probably be Brad. The emulsion tubes set up from the factory can/should work for a limited range of main jets and air correctors.

Turns out they're slightly less mysterious than derivatives futures: In conjunction with the main and air jets the emulsion tubes vary mixture within the rev range.

Holes toward the top - leaner transition. Holes toward the bottom - leaner at high rpm; varied widths play a compounding role.

[misterb]

Does anyone have a good idea what jets would be recommended for this wonderful 10% ethanol blend we're forced to use now (assume a stock motor)? The Weber tuning guides I've seen say the primary idle jet will probably need to be a little richer, otherwise you have to open the throttle so much to get it to idle you'll have very little adjustment left on the mixture screw.

I should note that this is probably more of an issue for those of us forced to deal with the DEQ.

[opus10583]

Does anyone have a good idea what jets would be recommended for this wonderful 10% ethanol blend we're forced to use now (assume a stock motor)? The Weber tuning guides I've seen say the primary idle jet will probably need to be a little richer, otherwise you have to open the throttle so much to get it to idle you'll have very little adjustment left on the mixture screw.

That's a damned good question, although I'm a little confused by that last sentence.

It looked for a quick minute that Congress had momentarily come to its senses to end the Corporate Welfare ethanol subsidy, but that was just misdirection from tax subsidies for private jets and McMansions.

[misterb]

I was confused as well when I first read it. Here's one source:

http://www.redlineweber.com/html/Tech/c ... _best_.htm

"At times it may appear to be showing signs of richness or flooding it is really a lean condition. See pictures and notes in the tech 2 article supplied in the kit instructions, view and please understand the need to keep throttle plate as near to closed as possible so as not to prematurely expose the transition holes. This is what causes the visible rich condition, and confirms the need to increase the jet size."

As I understand it, the now leaner fuel may require such a large idle speed opening that you're mixture is being more affected by the transition holes than the idle hole. The progression holes are only affected by the idle jet, whereas the idle hole is affected by the idle jet and the mixture screw.

[bradartigue]

I realize that different blends exist in different places but the blends here have made no difference, require no rejetting on any of the cars. Alfa twin carbs run fine, FIAT single carbs, FIAT FI, Alfa FI, Porsche IDFs, and so on. I'm using fuel from major chains, probably E90. I am worried about the corrosive effects of the stuff, but right now nothing seems out of the ordinary.

As far as emulsion tubes, the ADFAs installed on the 1800's are the same carbs with different tubes and jets, so you can mix them around if you like. I'd use the 49 State (non-CA) jetting as a baseline. We're talking about gains of 1-2% here at best, the 32ADFA being a rather small carburetor for the motor (though larger than the one they put on the 2 liter). If you're thinking about spending more than $50 on the 32ADFA then think about a new carb.

If you want to get it back to 1974 street-a-bility (the first year of the 1800) then use a 34ADF or a 32/36 DFEV. Both are more potent, hell the DFEV is $199 from webercarbsdirect.com, that's worth not even fooling with the old 32ADF. Of course the 34ADF and the 36ADL are still "the balls" in the single carbs. The 36ADL still makes those IDF twin-carb weenies shiver. But it is the A-Team of FIAT carbs...if you can find it...