Solex Carb Size ??

[rsw]

Is there a general rule as to what Solex carb is best for different size motors? I have a 1600 and have a 34 pict 3. On another forum a guy is wanting to build a 1641 and someone else suggested a Solex 30. I assumed a 30 was smaller then a 34, but I am new to the VW world. So what would be some basic guidelines on what carb to use on a what cc motors and what is the size difference in the Solex models?

[Marc]

A 34PICT-3 would be the preferred stock carb for a DP1600 (including slightly larger displacement, up to ~1679cc).
There were three basic variants of 30PICT carbs, used on 13/15/1600 singleport engines. The oldest (30PICT-1) was the simplest, the -2 was VW's first attempt at an "emissions" carb which I recommend avoiding; the -3 is good, if slightly trickier to adjust.
On the 1300cc dualports offered in other countries, VW went to a 31PICT-3 (similar to the 34, but with the smaller bolt flange of the 30s). Unless you had the manifold center section from one of those engines you'd need an adapter to run a 30 on a dualport. For a time years ago when there were few new 34PICT-3 carbs available many folks used the Brosol H30/31PICT "universal replacement" carb (with adapter) on DP1600s; they ran fine but gave up 2-3 HP off the top end...if mileage is more important than peak horsepower, a 30 would be acceptable but it wouldn't be my first choice.

[rsw]

Thank You again Marc, Do you know what cfm the 30 and the 34 are?

[rsw]

Found this on another forum.