Weber Carb Setup

[green69gtv]

I have located 2 Weber 40 DCOE's for my car. My engine is a 2L from the Alfetta, it has already been coverted from the fuel injection. Is there a base line setup that I can start with that will put me close to where I need to be?

[papajam]

Yes. Don't recall all the numbers off hand so I'll post them when I get home. What jets, e-tubes, chokes, etc are the carbs fitted with now?

[green69gtv]

I don't know all of that information yet. I'm still waiting to find that out, but they did say they would work with me on the jetting.

[papajam]

Well, I have only Dellorto and Solex specs for a 2l, not Weber. However, from the info on this site, jetting to get a stock 2l in the ballpark would be;

chokes (venturi) - 36mm
mains - 145
airs - 195
emulsion tube - F2
idle jet - 50F9
accel. jet - 35

But it's highly unlikely that the chokes in your Webers will be 36mm. Cross your fingers then that they are 32mm. Anything less and the engine will start to run out of breath around 5000rpm. If they are 32mm, stock 1750 jetting will work.

mains - 125
airs - 200
e-tube - F16
idle - 50F14
accel - 35

[green69gtv]

So , are you saying that I would be fine if I was to set up the Carbs with the stock 1750 setting? If so what would they be? P.S. Thanks for your help

[John M]

From the Centerline catalog:

..............................................1750 & 2000...................2000 Euro
..............................................40 DCOE 32....................40 DCOE 72 & 73

Venturi.......................................... 32......................................... 32

Aux Venturi...................................... 4.5 .................................... 4.5

Main Jet......................................... 130.................................... 135

Air Correct..................................... 200..................................... 210

Emulsion.......................................... f9....................................... f34

Idle Jet......................................... 50f8.................................. 55f17

Start Jet........................................ 65f5...................................65f5

Needle Valve.................................... 150.................................. 150

Accel pump Jet.................................... 35.................................... 35

Accel pump bp.................................... 60.................................... 60

Best Regards,
John M

[papajam]

Yes, stock 1750 jetting will work but I'd go with a 130 main instead of the stock 125. Stock 1750 jetting is;

venturi - 32mm
main jet - 125
air corrector - 200
emulsion tube - F16
idle jet - 50F14
accelerator jet- 35

[John M]

As Papa said....32 vents on a stock engine is a great place. Even the SKs that shankle racing sold had 32 vents. Just remember that as you move up in vent size, you are moving the power band up in rpms and as a result loosing some of that low end power. 32s and 34s are both probably very acceptable on a stock motor and keep the low end happy. Make sure that your carbs come with the vents that you want as they are pricey to change out.

Best Regards,
John M

[papajam]

Hmmmm. Slight differences here with the 1750 specs. Is it possible that Alfa changed the jetting when they went to the 10548 cams in 1970? The specs I listed are from owners manual #1373 dated July 1968.

And another simulpost w/JM!!

[John M]

Hey Papa:

I would guess that centerline bases their numbers from the conversion kits they sell. Maybe the carbs are slightly revised over the years??? Don't know. But either way Green will be close. That emulsion is right on the change over.

Best Regards,
John M

[papajam]

Agreed. The engine should run well jetted either way.

[green69gtv]

Thanks for all the help, I think that I have a good place to start with my carbs.