Originally posted by Tony:
The small primary throttle theory is an engineer's pipe dream . In all cases,adding a second carb on a Chevy 6 gave better fuel mileage if driven normally.This is well known by those who actually worked on these engines.We are takin old Chevy 6's here.
Several years ago wrote an article for Inliners on the various carbs I had tested out on a 261 engine,Holly 350 and 500 2bbls,old Carter WCFB and small AFB's and the butt ugly Pinto carbs, and even 2 Rochester B's.
In all cases,one the carbs were jetted properly,fuel mileage was all about the same,of course there was performance differences.
For better fuel mileage,work on the areodynamics.
My own experience has proven this to be the case. I run a 625 CFM Carter 4-barrel on my 64 Ugly Truck. If I stay outta the throttle in town, I get about the same mileage I got with the Monojet. On the highway I get 15 mph, same as before. In my case, the low gearing and the aero effect of pushing a barn door down the highway seems to have more to do with mileage (as does a heavy foot) than the carb.
Again, in my own experience, the only thing a 2-barrel carb has ever given me is less performance than a 4-barrel. I suppose you could say that it increases mileage by keeping me from opening up the secondaries (of which there ain't any) but I'd rather have the power on hand if I need or want it (and it DOES sound ossum when the secondaries open up thru the cherry bombs) and then take the blame for the lousy mileage myself.
