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Old 07-21-2004, 12:31 PM
jpd37 jpd37 is offline
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Knobie, Thanks again for the info. If I understand correctly, once I have calculated the VE, I should factor that value by 80% to arrive at the cfm of the carb? Or would I factor the value by 1.2 to compensate for the inefficiency?

I checked the Edelbrock web site and they recommend a 500 cfm Performer for 305 and smaller motors. My calc (307 x 4500) / 3456 = 399.8 cfm. If I factor it by .8, the result is 319.8 cfm. That is a long way from Edelbrock's recommendation of 500 cfm.

What makes more sense? It seems to me Edelbrock should not be very far off unless they are trying to satisfy small block motors with big cams and valves.

On the other hand, I have had several people tell me a 500 cfm is the right size for my motor.

Since I cannot seem to find parity with the numbers compared to recent discussions, I'm reluctant to make a decision. Maybe even 500 cfm is too much.
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