This is what I got "verbatum" from the Weber literature:
Quote:
The DCNF SERIES
The DCNF is a synchronous-opening, 2-barrel, down-draft carburetor, available in a variety of throttle bore sizes. Despite its compact size, it is capable of high rates of flow. Interchangeable venturi and accelerator pump cams add to the versatility of these units, which are particularly useful in applications where engine compartment limitations dictate a compact-size carburetor. Other features include diaphragm type accelerator pump circuits, separate starting circuits and ball bearing throttle shafts. The DCNF has been used extensively on Ferraris, and are well-suited to multiple-unit applications.
Now, the DGAS is a simultaneous 2 barrel carburetor, similar to the DGEV/DGAV ( the A and E differences within the DGV series correspond to water or electric chokes respectively) but the difference relies in the sense that both throttle valves open and close at the same time , delivering more power, at the expense of a little more fuel comsumption. What you sacrifice in fuel consumption you get back in more power band when using a DGAS carburetor.
Both throttle valves ( one per throttle/barrel) are actuated , in the case of the DCNF carburetor, by a single shaft, one shaft moves, and both valves have to move along.
The DGEV/DGAV carburetor ,( as well as the DGAS ) ,all have two shafts, one for each throttle valve, so each valve responds to a separate moving shaft. In the DGEV/DGAV the shafts move separately, hence the name progresive , in progression. In the case of the DGAS , both shafts move in unison, hence syncronious.
I posted a pix of the DCNF in the photo album section.
Apparently the DCNF is a good choice. I do not have direct experience, so hopefully someone can illustrate on the DCNF with direct experience.
Transfer
