Head Flow Numbas

[Super Bleeder!!]

i'm trying to gather flow numbers for different engine just to see how they compare. now when i see most flowbench numbers they do the intake and exhaust separately and at different lifts. is this to the entire (intake or exhaust) side of the head at the same time? or do they do each cylinder individually? some people also just say things like "this head flows X amount of cfms" so is that intake and exhaust added together or them just opening up the intake and exhaust valves at the same time and seeing how much flows through the head?

some numbers i've stumbled across are as follows (not to be taken as fact) [taken at 28" of water]

stock-ish 1g head [ 250cfm@.400 lift]
dsm race head [328cfm@.450 lift]
SHO [244@.400 lift]
b16 [250@.500 lift]
S2000 [330cfm@unknown]
z32tt [225intake/178exhaust@.400

mk4 GTE head
[[[[.100" intake 81 exhaust 65

.200" 155 122

.300" 199 145

.400" 207 151

.500" 215 152]]]

now how does the GTE head read compared to the others? do i add the values for intake exhaust at .500 lift or what exactly. it looks like a lot of people only look at intake numbers, but i could be wrong

feel free to add any realistic numbers you find or if you can provide some insight.

[1ViciousGSX]

Depending on who's doing the flowing, they would do 1 cylinder at a time, with 1 or both valves open at the same time.

[Shane@DBPerformance]

No you don't add the values. Flow bench numbers don't mean everything, but they are some sort of reference I guess. Numbers from different flow benchs aren't going to compare perfectly either. But, don't expect good numbers from the MKIV turbo head just becuase it is an almightly Supra and they can make shitloads of power with their 3 liters and 35psi of boost, it is not considered a good head design. DSM heads are better and Honda VTEC heads are very good.

[Super Bleeder!!]

yeah that seems to be the case, how much for Elite to put some b16 heads on an LT1 v8 there mr extranomeat?

[Raptor]

Like shane mentioned, the difference between benches and the different methods of testing makes it so comparisons not done on the same bench are not really trustworthy. The bench is just a good tool for use in design by measuring increases from a baseline.