important heads/cam question + an interesting thought

[FuryCharger]

pretty short but important question.....how do you match up cam specs to the flow numbers on the heads. Ive been doing a lot of studying with numbers and such, drawing graphs and pertentages. I found that stock when compared to supersix heads has a unique flow pattern. the supersix heads definitely flow more freely through the entire lift of the valve however, the airflow gain resembles a parabola (semi-circle curve) on a graph. What I mean by this is that when i started playing around with numbers and the math i found that the supersix heads flow about 17% better at .100" lift than stock. They also flow about the same at .500" lift (18% better than stock). The intriguing part is that SS heads only flow about 8-9% better than stock at .200" - .300" lift. This is the parabola resemblence I was talking about. It also means that stock heads flow very well, almost identical to supersix heads midway through the lift sequence.

I also compared the stock head flow to the intense stage 2 heads. I found something a little different. Instead of the flow forming a parabola curve it formed a straight constant line. What i mean by this is that at .100" lift Intense heads flow about 13% better than stock. This percentage is almost the same throughout the entire sequence of the lift.

So I am not sure which is better, the Supersix heads that flow real well at the start and end of the lift sequence or the intense heads that flow constantly better but lower throughtout the sequence.

I am not looking to buy either set of heads, i just wanted to see how flow numbers worked so i could choose an adequate cam. SO BACK TO MY FIRST QUESTION ~ is there any way you can match the cam specs to work best with flow numbers??

[foff667]

its kinda a toss up really do you have an overlay of the two flow sheets or can you do one so we can see exactly how they match up? Sounds like both would be good and make good power...also whats the runner volume on the two...bench flowing is only one portion on choosing a head the smaller the port the better the velocity so if you have a port of say 205 cc that flows 250 cfm at .500 vs a 225cc port that flows 252 at .500 id rather have the first as its a much better port design and would probably get you the same if not better real world numbers.

[FuryCharger]

my only question is how do u match up the flow numbers to the cam specs.....i just did all those comparison num,bers on my own time. my heads flow 2% better than supersix which puts them pretty close to intense heads

[oil pan 4]

Get the heads that flow the best in the low lift.
For a street car the heads that flow the best in the .300'' and less lift are idel.
It dosent make any sence to get heads that flow a ton at you max open if low lift suffers. You valves spend a small fraction of there open time at max lift. While the valve spends 3/4 of the time it's open less then half open.

[AZ3.8Camaro]

You need to match the flow of the heads to the lift you want to utilize. Doens't make sense to buy heads the flow well at .600 lift, when your cam only goes to .500 lift, etc.

Experience pays off here. As oil pan 4 said, you spend less time at peak lift, so you need to make decisions.

[FuryCharger]

So when testing the flow numbers on a set of heads, the only good that will do is determine how high a lift the cam can accomodate? You cant take into condieration LSA or duration? Also, when i was drawing out the graphs to all the sets of heads I noticed that all of them at some point leveled off to a certain extent. my question is, how do you know what the peak lift potential of a set of heads by just looking at the numbers or a graph. my guess would be that you take the lift where it begins to taper off. Any suggestions would be rgeat