General Cylinder Head Flow Numbers discussion

[SSDiv6]

Originally Posted by HawkBrosMav

Let me add a little more specific question to this:

.444 valve lift cam.

Lift -------- Head A -------------- Head B

.050 -------- 50.8 -------------- 35.1
.100 -------- 81.0 -------------- 57.6
.150 -------- 108 --------------- 88.2
.200 -------- 129.9 ------------ 117.12
.250 -------- 142.3 ------------ 136.6
.300 -------- 157.0 ------------ 158.0
.350 -------- 161.8 ------------ 172.6
.400 -------- 166.8 ------------ 175.6
.450 --------- 166.4 ----------- 175.6
.500---------- 165.8 ----------- 174.5

Which head would you rather have? Head B is a bit better up top but Head A is substantially better down low. I would still say looking at it from an area under curve stand point that Head B would be slightly larger but very small difference.

You need to take into consideration the intake manifold and throttle body flow also. No matter how much air flow you have on the cylinder heads, the intake manifold and throttle body/carburetor, can become a restriction.