16 replies to this topic

[Stephen Miller]

I am trying to find any technical information about Weber 58mm DCO side draft
carburettors as used on the early 60's Corvette Grand Sport. Pictures in
Friedman's book Corvette Grand Sport clearly show these to be a distinctly
different design than DCOE sidedrafts of the standard size 40-55 mm.

Appreciate any assistance anyone can provide.

cheers

Stephen

[Harvey]

I am trying to find any technical information about Weber 58mm DCO side draft
carburettors as used on the early 60's Corvette Grand Sport. Pictures in
Friedman's book Corvette Grand Sport clearly show these to be a distinctly
different design than DCOE sidedrafts of the standard size 40-55 mm.

Appreciate any assistance anyone can provide.

cheers

Stephen

Are these the same carbs as on the 2.5 / 2.7 litre Climax FPF?

[David McKinney]

Weren't they 58DCOE?

[McGuire]

In Weber-ese, 58DCOE means:

58: throttle in mm
DC: doppio corpo (two-barrel)
O: orizzontale (horizontal, obviously)
E: die cast (supposedly but not necessarily).

In practice the last letter may have great significance or little. For example, F in that position may mean Ford or Ferrari. Or not. In my copy (2004 edition) of Friedman's Corvette Grand Sport, the carburetors are described as 58DCOE models on pages 47, 54, 55, and 96, and that's what they look like to me. Not that DCOs would look startlingly different. To my tired eye, all Webers look similar but different, especially production versions. While most of the components are roughly interchangeable, there are significant visual differences among various Weber models through the years. (Mounting flange pattern, bowl cover attachment, method of retaining standoff tubes, etc.) Beyond the enormous throat diameters, what differences do you speak of vs. the more usual 40 and 45mm DCOE models?

[antonvrs]

Weren't they 58DCOE?

No, they were DCO which are very different from DCOE. For one thing, the DCOs have no ball bearings on the throttle shaft, which runs directly in the casting.
DCOEs have ball bearings at each end of the throttle shaft with little leather seals to stop vacuum leaks and there are really no interchangeable parts between the two types of carburettor.
There is also a considerable difference in value. DCOEs cost several hundred dollars used, sometimes less. 58DCOs cost several thousand dollars each due in part to their being used on some 4 and 6 cylinder Ferraris as well as 2.5/2.7 litre Coventry Climaxes in F1, also on small block Chevy powered Can Am cars in the early to mid '60s. They were also used on Abarth 1600 and Abarth Simca 2000 racing engines.
I've heard that Crosthwaite and Gardner has reproduced them but I've not been able to confirm this.
Anton

[Ray Bell]

It's possible, but only surmise, that the sand cast units were of a better material to cope with the throttle shafts running directly in the casting...

[Stephen Miller]

Thanks for all the replies.

Actually I think there were 58 DCO3 and 58 DCO4? They are different from the 40 -55 DCO(E) series. DCO's appear to not have a choke linkage mechanism while DCOE's do have a choke linkage mechanism. The 58 mm DCO have a different flange pattern for the manifold and for the intake trumpet side. The main float body and cover is also different in appearance.

This is a pic I found of 58 DCO3 since I originally asked the question.

http://www.racingico.../004/004-18.htm

The 58 mm size appears to be a none standard size which may only have been used for racing?

Hopefully more will be unearthed.

Stephen

[Terry Walker]

Here's a photo of the Coventry Climax carburettor setup on Bruce McLarens's Cooper Climax at the Australian GP in 1962. The hands at left are Bruce's.

[Stephen Miller]

Here's a photo of the Coventry Climax carburettor setup on Bruce McLarens's Cooper Climax at the Australian GP in 1962. The hands at left are Bruce's.

Yup, those look like 58 dco3's all right!

[kaydee]

I am trying to find any technical information about Weber 58mm DCO side draft
carburettors as used on the early 60's Corvette Grand Sport. Pictures in
Friedman's book Corvette Grand Sport clearly show these to be a distinctly
different design than DCOE sidedrafts of the standard size 40-55 mm.

Appreciate any assistance anyone can provide.

cheers

Stephen

Stephen, I have a photocopy of a Weber brochure for the 58DCO3 carburettor. It contains parts list and exploded view.
PM me if this what you are looking for.

Kaydee

[Peter Morley]

No, they were DCO which are very different from DCOE. For one thing, the DCOs have no ball bearings on the throttle shaft, which runs directly in the casting.
DCOEs have ball bearings at each end of the throttle shaft with little leather seals to stop vacuum leaks and there are really no interchangeable parts between the two types of carburettor.
There is also a considerable difference in value. DCOEs cost several hundred dollars used, sometimes less. 58DCOs cost several thousand dollars each due in part to their being used on some 4 and 6 cylinder Ferraris as well as 2.5/2.7 litre Coventry Climaxes in F1, also on small block Chevy powered Can Am cars in the early to mid '60s. They were also used on Abarth 1600 and Abarth Simca 2000 racing engines.
I've heard that Crosthwaite and Gardner has reproduced them but I've not been able to confirm this.
Anton

Another difference is the DCOs are sand cast rather than diecast, hence the different finish/colour.

There is a (mistaken!) theory that the material in DCOEs reacts with methanol hence they are unsuitable as replacements on methanol cars.

DCOs value really reflects their rarity (and the misguided assumption you need them on a methanol car), DCOEs are readily available and so much cheaper.
(n.b. there is a new version of the 58DCOE which appers to be called 58DCO or DCO/SP just to confuse matter).

Crosthwaite & Gardiner have made replica 58DCOs, to go with their 2.5 litre FPFs.

[dretceterini]

Weber codes are very confusing a 22DRS is a 1 bbl downdraft! In this case what does the "D" stand for?

[ovfi]

Weber codes are very confusing a 22DRS is a 1 bbl downdraft! In this case what does the "D" stand for?

I never understood Weber codes, but I knew that DCO stands for "Doppio Corpo Orizzontale" as McGuire said, because I have seen it in a Italian Weber manual for 40 & 45 DCOE's some 30 years ago.
If I remember correctly, the same manual says nothing about the "E" of the DCOE's.
At the same time, I had a pair of 48 IDA Webers who where "Doppio Corpo Verticale" (2 barrel downdraft), and its manual didn't clarified about the IDA meaning.

[RJE]

I am trying to find any technical information about Weber 58mm DCO side draft
carburettors as used on the early 60's Corvette Grand Sport. Pictures in
Friedman's book Corvette Grand Sport clearly show these to be a distinctly
different design than DCOE sidedrafts of the standard size 40-55 mm.

Appreciate any assistance anyone can provide.

cheers

Stephen

Stephen.

I have the Weber 'Catalogo Generale' dating from 1961 which covers the 58 DCO3. If you would like to get in touch via email i will copy it for you.

Regards

Bob.

[scooperman]

There are a pair of 58 DCO3 carbs on ebay.co.uk today. I have no affiliation with the auction.

[T54]

They look a little corroded for the very high asking price.
I like the seller's comment: "Don't let your car run on inferior reproductions".
I would believe from experience that the C&G reproductions are probably better than the original...
Hey, never mind.

[lsg5784]

Yes indeed, Im not sure I have anything to add at this point, but, they are sand cast 58 DCO 3 carbs as used by Abarth,Cooper,Chevrolet, Ferrari (4cyl)and on several US specials with Mickey Thompson intake manifolds. All for racing .
Which tends to indicate very few have been made in the day when compared to 40 and 45's, and others.
Crosthwaite and Gardiner in the UK has made complete replicas. I also believe that Hall and Hall in the UK have made up a batch as well? I think both examples are excellent reproductions used for racing restorations on Ferrari 500 Mondial and Climax engines for GP . Technical info does exist in the form of the orignal Weber booklet on the care and feeding of them ..

I'm sure you have seen that a pair sold at an Italian auction for $40,000 + at one point which was about 25 k more than they are worth in my opinion, but hey, thats the auction business !
lsg5784