What you are supposed to do is *be realistic* about what max RPM you will be running at, and find the CFM that will get you 100% VE at that RPM. Using the formula to find a carb that will get you 75% VE at your max RPM kind of defeats the purpose of using the formula if you ask me.
Now, it's true that there are factors other than the carburetor that contribute to whether or not you are getting 100% VE at max RPM, but that doesn't mean you should choose a carburetor that will guarantee you not to get better than 75%. John Nasta -----Original Message----- But...you're lucky to get 75%-80% VE on any given street engine. :*) A normal street 283 isn't going to see the high side of 5500 and live very long either, to be honest. So...in the real world 283 * 5500 / 3456 = 450. Multiply that times 75% and you get 338. Of course, there are always exceptions and VE can vary - but not much. :*)
