13 replies to this topic

[scotchmist]

I've just come into possession of a weber DCOE 40 carb and I'm looking for a little advice.

1. On the carb is stamped 40DCOE 35 No. 3, what does this denote?
2. Can the main choke only be identified by measuring it's internal diameter as it doesn't appear to have anything printed on it?
3. How can you identify what auxiliary venturi is fitted (again it has nothing printed or written on it)?

Ideally I'd like to try it out on my engine.
Basic spec:
1293
276 cam
big valve head (36, 31)


The carb itself is as follows:
Choke 35?
Main jet 165
Air corrector 180
Emulsion tube F3
Pump Jet 45
Idle 45F9
Needle valve 175

I understand the complexity of such a question, but it is likely that I would be able to get the car running with this spec in preparation for a rolling road.
If not, any advice on alternative settings for the carb. I intend to rebuild it prior to use, so any changes can be made at this stage.
Sorry for the length of the question...

[scotchmist]

Here's the chap, any ideas?

[scotchmist]

Bump

[Phaeton]

I'm sure somebody who really knows what they are talking about will come along shortly & give you the proper information. But I was going to fit a Weber last year, a 32/36 I think, anyway told the local guy who does my tuning & he reckoned just put it on & get it running then bring it straight to him, he would then rejet etc.

Alan...

[HARBER07]

I know that the carb number denotes various things like the position of the progression holes, accelerator pump stroke and type of float - what your carb actually has i dont know. Cant help with the rest im afraid as im trying to get help on jetting mine

[Saxo-Fiesta-Mini]

as long as the jet isnt blocked should be perfect i like it

im going the twin su route as i want economy as well as power hehehe well thats the plan id say u should be fine with that
make sure it runs a lil rich b4 u drive to the r&r that way u wont damage anything

[Rosslin Racing]

I've just come into possession of a weber DCOE 40 carb and I'm looking for a little advice.

1. On the carb is stamped 40DCOE 35 No. 3, what does this denote?
2. Can the main choke only be identified by measuring it's internal diameter as it doesn't appear to have anything printed on it?
3. How can you identify what auxiliary venturi is fitted (again it has nothing printed or written on it)?

Ideally I'd like to try it out on my engine.
Basic spec:
1293
276 cam
big valve head (36, 31)


The carb itself is as follows:
Choke 35?
Main jet 165
Air corrector 180
Emulsion tube F3
Pump Jet 45
Idle 45F9
Needle valve 175

I understand the complexity of such a question, but it is likely that I would be able to get the car running with this spec in preparation for a rolling road.
If not, any advice on alternative settings for the carb. I intend to rebuild it prior to use, so any changes can be made at this stage.
Sorry for the length of the question...

the chokes have numbers on them ie 36
in fact all the parts have numbers on them to help ID. get a pro serie book on the weber carb all your question and more will be answered.
Vizard can also help you, have that book i see the answers in the book.

[Kerrin]

Its been a while since I had one in bits but My 40 is somewhere in the shed.

If you undo the 4 nuts that hold the trumpets in, and take them out. On a 40 they are sleeved.

once the trumpets are out of the way then pull out the auxillery venturis, they are held in by interference fit with a spring, they should have the number cast somewhere on the outside.

Then slide out the chokes (same method) if there is nothing stamped on them they may have been modified (lathe job) but you can measure the inside diameter at the back with a vernier to get the choke size. it will be somewhere near 30-36mm.

When you put them back together make sure the chokes and venturi's are in the right way round.

The numbers on the top refer to the version of the carb, some are origional equipment on cars like the old Avengers and Lotuses. these may not work on other cars without modifying but nothing looks to different on yours so its probably fine.

Maybe you could take it to a good rolling road to assess it before it is fitted so you dont waste your money.

[scotchmist]

Thanks for the help.
I've checked the auxiliary venturis and chokes again and can't find any markings. I guess I'll just have to measure them and see. I may give it a whirl and see how it goes...

[scotchmist]

Just one more question.
If I were to rebuild the carb, there are a few options on the size of the needle valve.
I had a look in Vizard's book, and there doesn't seem to be mention of it.
The options are; 175, 200, 225 and 250.
Given my engine spec, which is the most likely to be appropriate?

[scotchmist]

Ideas?

[scotchmist]

Bump

[mini_kel]

Leave the needle valve as is!

[Rosslin Racing]

the size of the aux is on the outer ring, stamped in.