what does IDA, IDF, ICT stand for when talking about carbs?

vdubvr6 · Post by **vdubvr6** » Wed Oct 06, 2004 8:49 pm

um, yeah, what the subject said!!

just wanna know differences and what not! thanks guys!!

VGM · Post by **VGM** » Wed Oct 06, 2004 9:20 pm

Generally speaking here is a run down on the differences:
The letters are model designations followed by the throttle size in millimeters.
The Weber ICT 34 is a single throat dual.The Weber tuning book I have calls it a primitive design but they work well for smaller street engines unless your trying to pass an emissions test.
The Weber IDF comes 36,40,44&48mm.It is a very popular dual throat.It is used as a dual and often as a single carb(with different jetting).It is a great street/strip carb.
The Weber IDA 48 is a serious race model.It can be modified for the street and often is.It is also often modified into much larger throttle diameters for monster engines.

vdubvr6 · Post by **vdubvr6** » Wed Oct 06, 2004 11:59 pm

thanks for the explination on that! i kinda knew the difference in performance already!

what i wanted to know is what the acronym stands for! sorry for not being more descriptive before! LOL = Laughing out loud; IDF = ??????

sideshow · Post by **sideshow** » Thu Oct 07, 2004 10:32 am

Keep in mind I am just making stuff up here;

The I is down draft
The middle D is dual barrel
The last F is Ferrari

So IDF means ?works well on ferrari, good luck" my italian sucks.

A might be Alfa or Porsche I doubt it it means Ford/GT40. The ICT I think is a tractor or econo box part.

Bruce2 · Post by **Bruce2** » Sun Oct 10, 2004 3:11 pm

Close, I is for Inverted, what Italians call downdraft.

F is for Fiat in this case, not Ferrari.

vdubvr6 · Post by **vdubvr6** » Tue Oct 12, 2004 12:04 pm

would a Weber Progressive fall into one of these catagories? is there a such thing as a dual progressive set-up and is it a good idea?

Bruce2 · Post by **Bruce2** » Tue Oct 12, 2004 12:13 pm

Progressive 2 bbls have different letters designating them.

Its been my observation that a 2bbl progressive carb is only good for increasing fuel consumption. Two of them would be a disaster.

Post by **Marc** » Tue Oct 12, 2004 12:19 pm

The Weber progressive is a "32/36 DFEV" or a closely-related variant. The "DG" family is a mirror-image cousin so you should be able to use a DF on one side and a DG on the other to simplify the linkage.
Claude's Buggies once sold a setup for dual progressives based upon a smaller series; I had a customer who put one on his baywindow bus 1600DP and loved it once we got the linkage sorted out, performance felt comparable to Kadrons to me. I've never seen a dual setup using DFEVs but unless there's some problem with float-level control when turned sideways the only reasons I can think not to use them would be space considerations in a bug engine compartment and possible transition problems (like getting the power fuel circuits in both carbs to work evenly). The problems usually encountered with single progressives are typical of any center-mounted carb...

VGM · Post by **VGM** » Thu Oct 14, 2004 7:53 pm

I have one side of a pair of Scat intakes for a Weber progressive setup.I always wanted to try it but the other side has eluded me.If it was such a great idea it would have stuck around i would think.

sideshow · Post by **sideshow** » Thu Oct 28, 2004 11:37 am

I would like to revise my guess loosely based on the ?Weber Tech Manual By Bob Tomlinson Copyright CB performance 1998? http://cbperformance.com/catalog.asp?ProductID=4

ICT

...variant of the Weber IRC series of carburetors that at one time were supplied to the Chrysler plant in France.

I still think T is tractor, don't see any evidence however. It could mean ?minus the water choke or cold start device.?

Does C mean one barrel or used one per engine?

IDA

...destined for use on water cooled Italian V6 and V8 racing engines.
also
Motori con Cilindra AV

It sounded like the IDA prefix means racing only. The only OEM listings I saw were Porsche (904/911/914-6).

Weird the the 911S had OEM IDS, 911T had OEM IDT or IDTP, and the 914-6 had IDTP. So they were not all racing only models and more common in 3 barrels than 2.

D must NOT mean dual barrel, maybe D is used in pairs?

IDF were listed as used as OEM on Fiat, Ford, Lamborghini, Lancia, oddly no Alfa Romero OEM listings. The guess is that F is Fiat due to volume or used first, however that same argument could be made for Lamborghini. So F is Lamborghini?

So I didn't find a letter breakout codes and am more confused now more than ever.

Bruce2 · Post by **Bruce2** » Fri Oct 29, 2004 11:57 pm

sideshow wrote:
It sounded like the IDA prefix means racing only. The only OEM listings I saw were Porsche (904/911/914-6).

The IDA was introduced in 1964. Prior to that, the IDM was used. An IDM is almost exactly the same as an IDA, but a little more crude. I have seen references to use of the IDM back to 1957. One famous use of the IDM was on Masaratis. Thus the M is for Masarati. My guess is that when they redesigned it, they were using them on so many other cars (Porsche, AC Cobra, Masarati) that they gave it a neutral application letter "A"

sideshow wrote: D must NOT mean dual barrel, maybe D is used in pairs?

D means double choke, definitely. IDAs were used in pairs and sets of 4 and 6. The number of carburators on one engine has no effect on its type designation. There have been some cars that only got one IDF.

sideshow wrote:IDF were listed as used as OEM on Fiat, Ford, Lamborghini, Lancia, oddly no Alfa Romero OEM listings. The guess is that F is Fiat due to volume or used first, however that same argument could be made for Lamborghini. So F is Lamborghini?

Lamborghini gets the letter L, as in DCNL. This is the Lambo version of a DCNF. If an existing carb works perfectly on a new application, they don't change the letter. IDFs have been installed on Lamborghinis. The DCNL is a radically reworked carb, specifically designed for Lamborghini.

Slow 1200 · Post by **Slow 1200** » Sat Oct 30, 2004 8:03 am

Bruce2 wrote:D means double choke, definitely. IDAs were used in pairs and sets of 4 and 6. The number of carburators on one engine has no effect on its type designation. There have been some cars that only got one IDF.

What about the three choke 46 IDA 3C used in 911s?

Bruce2 · Post by **Bruce2** » Sat Oct 30, 2004 8:34 am

Since the IDA3C is a carb based on an IDA 2bbl, it got the same IDA, but the 3C stands for 3 chokes.

sideshow · Post by **sideshow** » Sat Oct 30, 2004 9:05 am

Bruce2 wrote:Its been my observation that a 2bbl progressive carb is only good for increasing fuel consumption. Two of them would be a disaster.

That kills me every time I read that.

I have taken a close look at a 914-6 induction system, despite going to public schools I can say that there are 2 carbs, and 3 barrels each.
EDIT: 3C/1 they do like they are retro fitted to add another barrel rather that designed that way from scratch.

D might be port on port? Just throwing out more theorys.

The book implies that Lamborghini was first with the IDF but I agree that Fiat make many more cars and If I was Weber I would make first for Fiat, then for the low volume builders.

VIPERGREEN76 · Post by **VIPERGREEN76** » Sat Nov 10, 2018 12:55 pm

To me, IDF means.

I=individual
D=dual
F=fuel

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what does IDA, IDF, ICT stand for when talking about carbs?

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