I'm planning to take Darwin off the road pretty soon to swap the current cam with a milder one -- Either a Comp 240H (192/200 [email protected]; .390/.390 lift; 108 sep) or a Crower Level 1 (182/190 [email protected]; .386/.387 lift; 114 sep) along with a few other things. Since I'll have to retun the carb anyways, I'm wondering if I should just go ahead and swap the current 465cfm 4160 with a smaller 390cfm carb.
My understanding is that the traditional cfm calculations yield the following:
Needed CFM = (262cuin X 5500rpm)/3456 = 417cfm
%Eff = 390/417 = .935 = 93.5%
I have been told that a mildly warmed over engine (like Darwin's) should have an efficiency in the 85-90% range, thus a 390cfm 4160 would be perfect. Is there anything I'm missing?
What should I expect to gain by going down from a 465cfm Holley to a 390cfm Holley?
Thanks,
Darwin's Keeper
My understanding is that the traditional cfm calculations yield the following:
Needed CFM = (262cuin X 5500rpm)/3456 = 417cfm
%Eff = 390/417 = .935 = 93.5%
I have been told that a mildly warmed over engine (like Darwin's) should have an efficiency in the 85-90% range, thus a 390cfm 4160 would be perfect. Is there anything I'm missing?
What should I expect to gain by going down from a 465cfm Holley to a 390cfm Holley?
Thanks,
Darwin's Keeper