I built race engines for a track where we were required to run a Holley #7448 2 barrel carburetor, commonly called a "350 CFM" carb. Now, it was possible to flow a LOT more air than that through it. A 350 Chevy engine would run 6200 RPM on that carb, which was WAY above the advertised volume, but the manifold vacuum went up to the point that the engine simply couldn't suck enough air, air/fuel mix, or peanut butter, I suppose, to wind any tighter. The carb served the same purpose as a restrictor plate on NASCAR superspeedways. There was no point in doing a lot of mega-dollar engine building with big valves, big ports, and ultra-hot camshafts and trying to feed a beast like that with an undersized carburetor. It was the racing association's way of controlling engine building costs and making the guys on a limited budget competitive. Did we find ways to cheat?- - - - -Of course we did! The same carb on a 250 cubic inch engine with a super short stroke would turn at least a thousand RPM faster than the 350's. Once my guy managed to get out front and keep the engine wound up, nobody could get within half a lap of him. My engines wouldn't pass a full teardown, but nobody wanted to put up the big bucks the track required for a protest, and their tech inspectors were too dumb to figure out what I was doing.
Jerry
