Jimmyz

iTrader: (3)

and when I ask this, I mean on a Superflow 600 or better. No pipes, no clay, no horns or intakes. Just the normal calculation w/28" of water.

Is 330cfm a good peak number @.600 on the intake side? What about 230cfm on Exhaust?

<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

<small>[ March 18, 2003, 06:20 PM: Message edited by: Jimmyz ]</small>

strokedls1

iTrader: (1)

With what size valves? My stage 2 5.3L flow 310 237 with 2.055 intake 1.60 exhaust valves at .600. I would say 330 intake would be a max flow rate at that .600 lift. The velocity is equally important to take into account.

Godspeed

I know some do 335CFM.

kumar75150

dude, where did you get those heads? I am looking for some.

Let me know what numbers you make with the new heads and cam. My 382 is about to start getting built. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

J-Rod

The big Bore heads will flow over 330. Most std bore motors are a bit less. Keep in mind that the SAM Camaro had a set of LS1 heads flowing 325 way back in the day (with lots of work). I have heard of heads close to 350cfm. But then the restriction is still the intake and once you put it on, you are only about 10CFM up over a head with much lower flow numbers.

Pro Stock John

iTrader: (34)

Perhaps an experienced head porter can answer this, but how much will you pick up going from a 2.02 intake to a 2.08 intake, could be 10+ cfm right... And the flow will not take into account velocity or shrouding issues.

Jay 95WS6

raw flow #'s don't give you much info unless you're racing a dyno what you need to know is the runner volume so you can proplerly assess the porting of the head and if it will work on your car in your application
an example:
head a flows 350cfm with a 300cc runner( not reality i know)
head b flows 300cfm with a 200cc runner
which is the better head?
the lower the intake runner volume the better it is for smaller cubic inches and or lower rpm range when you go up in runner volume you need more air to fill it so you need more rpm and cid to do that efficiently. so what i am saying is the runner volume vs the cfm is a better way of picking the "best" head for you application( rpm range, cid,etc)

Jay

Jimmyz

iTrader: (3)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by strokedls1:
<strong> With what size valves? My stage 2 5.3L flow 310 237 with 2.055 intake 1.60 exhaust valves at .600. I would say 330 intake would be a max flow rate at that .600 lift. The velocity is equally important to take into account. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I would say 2.05 in. and 1.60 ex. would be about right. I figured 330cfm was a MAX number to achieve.

Linear Velocity

iTrader: (1)

The LS6 heads on the SAM car flowed 358 cfm @ .650 lift, I would say those are good. Although mine are only 6.0 liters they flowed 352 cfm @.600 intake and 242 CFM @. 600 exhaust <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

HP-GURU

Why are we talking about 358CFM when the intake only does 280?

We should more considerate of flow numbers from .200-.500" and not worry about the peaks, because your induction system does not support those high flow numbers.

LS1derfull

PSJ, i dont feel LS1 bowls are large enough to support any valve larger than 2.055". The LS6 head has more compatible bowl size for large valves, but i dont see any reason to install 2.08" valve in these heads.
Velocity should not be hurt by larger valves, and shrouding is in Comb. chamber not really in cylinder. 10cfm is realistic but not worth trading mid lift flow for top lift flow gains.

<small>[ March 19, 2003, 09:24 PM: Message edited by: LS1derfull ]</small>