262 vs 267 sbc

[Billy Nees]

Originally Posted by Dean Feiock

So how does one work around the Dual Jet? Or should I ask how much HP can be made on a carb rated at 287 CFM?

It gets even more interesting if you convert apples to apples. Since a 2BL is flowed at 3 inches vacuum and a 4BL is flowed at 1.5 inches of vacuum, you need to multiply the 2BL CFM by roughly .707 to get a value you can directly compare to a 4BL carb.

So 287 X .707 = 203 CFM

Using a quick online CFM calculator:
267 CID, 5500 RPM, 80% VE........ would need about 350 CFM minimum

Well, let's see, with a (seriously) restricted engine you don't think about making HP. You make as much torque for as long as you can.
I can assure you that a 287 CFM 2V will be flowing at least 100% VE. How can I say that? If everything is right in the combo, the engine WILL be pulling vacuum long before it gets to the finish line. OBTW, try explaining that to the man designing your cam.