The Stovebolt Site Forums The Shop Area Engine Shop Planning dual carbs on my 235 build

Jerry,

Thanks for the comments.

I'm realizing that the 216 carbs are not the way to go. Looking at two Weber 32/36s really. The bore area of the Weber primary is 70% of the 216 Rochester. Ideally it would be 50% for two to perform as well as a single 216 carb, but that's getting closer. My engine being a 243 now, gets it even closer. Three fifths of the way there, or you know, 60/40, better 60 than 40.

But really, I should be looking at comparing it to a single 235 carb with a 1 9/16" bore. So then the Weber primary is 65% of the Rochester. Even closer.

In addition, I turned up a Datsun forum that suggests the Weber 32/36 was designed for displacements between 1200 cc to 2300 cc, so 73 to 140 cid for a single carb, or 146 to 280 cid for two, which puts it in the 235 range, or in my case 243.

Guess I shouldn't really have mentioned the two 216 carbs in my original post as I've pretty much gone away from that route. More looking for flaws in my reasoning on going with the Weber 32/36s.

My question should have been am I on the right track with the Weber 32/36? Am I thinking along the right track? The bore area discussion was mainly referring to the lower rpms.

Kinda getting into this. Thought about calculating velocity through the bore of each carb at different engine RPMs, but realized I'd have to account for the different position of the throttle plate. Too complicated for tonight.