Carburetor sizing?

[Pete Gossett]

I've found the formulas to size carburetor CFM based off engine displacement & max RPM. For the Zetec at 7000rpm, that would be about 245CFM max. From what research I've found, Weber 45 DCOEs flow 400CFM each, which seems massively oversized for the engine?

I've not really heard found any problems from people with 45 DCOEs on a Zetec, other than the need for either the 152G model with 4-progression holes, or the 5-progression hole model. But is there a benefit to going that much larger?

[LotusJoe]

Pete, IIRC I have 40s. I will check.

[LotusJoe]

I was wrong. I'm using a pair of 45s.