WEBER 30 DIC TWIN CHOKE CARB

[Rusty's Uncle]

Got a spare one if anyone is serious about tuning an air cooled 

[Cookie126]

might be interested!

[Rusty's Uncle]

Things you need to know as lots of owners have asked how to get a quicker 126 over the years. If you are looking at engine improvement/tuning then you you have to consider a package as no one thing is going to make you faster away at the lights. Hudsonhenry said that fitting a big carb on a standard engine is like putting a sock down the front of your trousers, looks impressive but that is as far as it goes. There has been a lot of "eye wateringly" exspensive work done on the iconic air cooled engines going way back to the early 500s . Getting the best out of your little 2 cylinder engine seems to have been an historical challenge for many years and I can not see anybody getting out in front of Smallcox. So for normal mortals where do you start. These are my views on the "package" and I think that you need to think about cylinder head work, camshaft , carb & exhaust as a starter.

[Cookie126]

I've found lots of good info on the precious threads, all makes sense. Thanks for the advice!

[Rusty's Uncle]

Although I have been messing with these little cars since the late 70's on & off it is only in the last 5 years or so that I started looking into tuning and been on a learning curve myself. Some lessons were learnt the hard way 
In my opinion the work that gives the biggest gain & is probably most expensive is on the cylinder head. Porting , skimming , bigger valves , valve mods etc all possible but specialist work. A sporty cam is an off the shelf item but if you are running an early engine then a cam from a late 126 can give you a gain. Exhausts , well take your pick. As for carbs there are no "just bolt on" options that I know of and special inlet manifolds are required . The most popular carb choices seem to be the Weber 30DIC and the Dellorto FZD. These are quite hard to get hold of and pretty pricey then there is the rarer Reece Fish carb that I have no experience of. If you have a manifold to suit a Dellorto FZD then you can also fit the very common SU from a Morris Miinor but not sure if they are better than a standard carb and much as I love the SUs it seems wrong to me to fit something essentialy British to something Italian 

[Topolino]

Hi,
A shop owner who also is racing with the FIAT 500 just told me that the 30 DIC from a 850 Spider will not run on a 650. So now I wonder who is right? I'm reading stories which tell both options are possible.
And if the DIC will not run, this will be sad because I've all invested into a 30 DIC. It is on the shelve but do not have the proper part to connect it to the cilinderhead.

Can anyone clear out this foggy mistery? 

[Hazey-n-Marc]

Rusty knows his stuff. It depends how far you want to go with it though, check out smallcox's car.
http://club126uk.co.uk/smf/index.php?topic=6149.0

[DEYAN IYI]

Hi!

First of all there is not a carb in the world that you can transplant from one to another car expecting optimal working, so that guy is kind of right. You will always need to play with jetting unless you have a luck. "Luck" would be if you have Panda 30 Weber 30 DGF to fit over 650cc, cos it's almost the same engine. If you compare the jetting of 30 DGF and 28IMB, you'll see that the Panda's one is really close to 2x28IMB.

On second place there are different 30 DIC models. On other hand 30 DIC and 30 DGF are really similar gadgets except the secondary butterfly mechanical vs. vacuum. I would say, if you make tuning  experiments, DIC is to prefer.

Mount the one you got and find a pocket of jets, put A/F meter and start playing  

[Hazey-n-Marc]

The BIS used the 30DGF as well.

[DEYAN IYI]

Yes. Panda 30 venturi's 2x23mm, Bis I-18mm/II-19mm. So, no sport . Cinquecento 700 also 30 DGF, not sure about diameter, but with automatic starter.

[DEYAN IYI]

http://www.fiatforum.com/500-classic/301381-new-again-forum.html

[Rusty's Uncle]

I see that there is a good old bit of tuning chat on the forum again 
DEYAN you have confirmed that I was thinking in that the Weber 30 DIC is very much like two 28 IMB carbs bonded together so I think that it is worth comparing jet sizes to guess a suitable set up. The early 30 DIC carbs had a 23/21 venturi size then went on to 23/23. I had not realised that the Bis was that restricted but it may be worth looking at the main/air jet ratio as a further guide.

[Topolino]

You guys might like this...



No need to surge for other carbs. Everybody got some extra IMB's on the shelf.

You can see that one of the carb. is above the intake port. I wonder what that means for the ones on the sides. Will there be no interferances is some way?

[DEYAN IYI]

I see that there is a good old bit of tuning chat on the forum again 

 

Now we now the venturi size of Cinquecento 700:

Weber 30 DGF 7/750 I-19mm/II-21mm
FOS 30 S2HX I-19mm/II-22mm

So, he, who wants to awake his Bis in the high revs, can fit a CC700 carb. 

Soon I'll try to make a comparative table of all Weber carbs for 126/Panda 30/Cinquecento 700

PS - Topolino, what's that triple torture  Masochism with no limits

[Topolino]

Hahaha  ... this picture came from Dutch FIAT500 Club forum.