Carb question for L20b

[AZhitman]

Apologies for the n00b question, but I have a Weber 40 DCNF here (freshly-built) and my manifold is designed for a Weber carb... Can I run this on my L20b? Good choice?

[Wide14u]

sounds like its a little big for it

[Pacific coast Datsun]

Is the Weber 40 DCNF a single side-draft ?

Had a friend [ryan in Seattle] who ran a Weber 45 single side on his L 20 powered 620 & it hauled butt.

Should be fine.

[ggzilla]

my manifold is designed for a Weber carb

 

It is designed for a specific type of Weber carb. If it is a downdraft, it's for a Weber DGV (32/36). For sidedraft, it will be Weber DCOE.

 

Weber DCNF is different from those. It's a synchronous 2-bbl downdraft (a 40/40) as used on many Ferrari.

[ggzilla]

bolt patterns

DCNF: 85 mm x 52 mm

DGV: 93mm x 46 mm

 

So it won't fit. But you can make an adapter, or use the stock L-series manifold and drill new holes.

 

A 40/40 is a large carburetor for a 2-liter. They use 40 sidedrafts, but that is ITB for twin DCOE or 2 cyl per bbl for a single DCOE 40. On a downdraft that's both barrels feeding all cylidners -- way different. Except that DCNF is highly customizable. So if it has smaller venturis fitted, it would be good for a 2-liter. With the largest venturis it would be too large.

 

How stock is your L20B, and what size venturis are in the carb?

[AZhitman]

The manifold is designed for downdraft.

 

OK, so that answers that question... :)