Picked this up, want to use it on a 327 to 350 SBC 8:1, 4-71 at about 8 psi. The idle circuits and main jet circuits are missing ( no biggie I figured I would need to rejet anyhow) Looking for Weber guru who can reccomend main jet sizes, emulsion tube sizes, idle jet sizes, accelerator pump jet sizes float seat etc. I will probably get a jet kit, but it only comes with mains and idle jets in 8 incremental sizes, so I need to be close on the other sizes before trying to dial in the final jetting. Carbs are Italian made Weber 40DCOE32 models. Can they work on a blown mild SBC or do I need to step up to 45mm or 50's ? THANKS Nitro
That's about 1/2, or less, of what you wound need for your application. I have fairly routinely installed two 40s, and eve 48s on air-cooled VWs. This is a 348: Not one of mine, but it shows how many can be used.
Dual 40s are customarily found on 1.6l to 2.0l 4-cylinder engines. A 289 Cobra had four 48s, and no blower.
The biggest benefit of the Weber (and similar) carburetors of this type is their IR (individual runner) design. Each barrel services a single runner, to a single cylinder, for maximum efficiency. Once you dump all of that into a supercharger, that benefit is void. At that point, you are just in in for the look.
Inglese's website shows a couple of setups with 2 weber carbs on top of a blower (4-71), so it seems like it's doable. There's no information beyond the images, but an uneducated guess is that it goes on top a pretty small engine with low boost. They also have an intake for 4 carbs on top of a blower. I agree with gimpy that it's just for looks... but it's a pretty cool look (well... the blue finish, not so much).
B&M offered 2 40s on their 144 as there is a big demand difference between plenum and individual runner
1 tube feeding 1 runner, but with blower and single plane I essentially have 4 tubes feeding 1 runner at a time. I actually think a 45 or 48 is too big, that is why they chose 40's
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