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Old 03-08-2012, 08:15 PM   #4
ProStreet68SB
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Join Date: Sep 2006
Location: Ohio
Posts: 770
Re: Is a 750 carb too big for a 327?

Quote:
Originally Posted by kriswvu1202 View Post
The way to accurately size a carburetor for an aplication is to take the cubic inches divided by 2 multiplied by the maximum RPM over 1,728. (327/2 x 6,500/1,728) = 615.017. The biggest carb your engine will need is a 650 cfm, and unless you plan on running wide open, high rpm all the time, a 600 cfm will be plenty. Plus, with a smaller carb, the throttle response is much better. The P.O. of my truck put a 750 cfm Edelbrock on the original 307. It ran fine, but was an absolute dog when you put your foot in it. Just bogged and accelerated lazily. I switched to a 600 cfm Holley and the difference was like night and day. Much crisper and when you stomp it, it goes right now...That said, I have a nice 750 cfm Edelbrock performer I'll sell you cheap. HAHA
That is all very true. Also remember that equation is designed for motors that are 100% volumetric efficient. Most street motors are lucky to be around the 80% range.
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