advertised head flow figures, any specific way of measuring on the bench?

[Martin]

no point comparing them, my set we tested are 4" 53mm x 40mm tested thought the manifolds with a clay ring.

but they are way higher that the numbers you've posted. John Calibrated his flow bench to 300 cfm @28" before the tests.

at 0.700" lift they are flowing 321 cfm = 117.4 cfm per square inch

at 0.800"lift they are flowing 334.2 cfm = 122.2 cfm per square inch

the bit we thought was really good they are flowing 77.4 cfm @ 0.100" lift

[Big Power]

The 94mm bore Strip Dominator was flow tested on our Superflow 600 bench. Our bench uses a FlowCom and is pretty hard to screw up flow numbers. We flowed the head to .800 lift. Our bench is calibrated every 2 years by SuperFlow. What we state in our advertising on flow numbers for the Strip Dominator is correct. Maybe the bench the head in question was flowed on was not correct? Our 4" bore Strip Dominator is on Eric Calabrese's pro Mod car. They had their heads flowed by an independent source and the heads flowed more than what we stated. Flow benches are like dyno's, they all can read different. They are a tool to use for back to back testing, seeing the results whether good or bad.  
   Bang, FYI yes there was a spark plug in the head during testing.

[JS]

The 94mm bore Strip Dominator was flow tested on our Superflow 600 bench. Our bench uses a FlowCom and is pretty hard to screw up flow numbers. We flowed the head to .800 lift. Our bench is calibrated every 2 years by SuperFlow. What we state in our advertising on flow numbers for the Strip Dominator is correct. Maybe the bench the head in question was flowed on was not correct? Our 4" bore Strip Dominator is on Eric Calabrese's pro Mod car. They had their heads flowed by an independent source and the heads flowed more than what we stated. Flow benches are like dyno's, they all can read different. They are a tool to use for back to back testing, seeing the results whether good or bad.  
   Bang, FYI yes there was a spark plug in the head during testing.

Hi Pat, did you use 25" or 28" in these tests?

[K-Roc]

no point comparing them, my set we tested are 4" 53mm x 40mm tested thought the manifolds with a clay ring.

but they are way higher that the numbers you've posted. John Calibrated his flow bench to 300 cfm @28" before the tests.

at 0.700" lift they are flowing 321 cfm = 117.4 cfm per square inch

at 0.800"lift they are flowing 334.2 cfm = 122.2 cfm per square inch

the bit we thought was really good they are flowing 77.4 cfm @ 0.100" lift

Hi I just read your results per square inch...  An NHRA Pro stock hemi gets 116 cfm per Sq inch of valve area, and advanced wedge head is 95-98 cfm and  a few rarities touch over 100 cfm/ sq inch at .800"

Here's my math...

Your head flows 334 cfm at .800"

53mm intake valve = 2.087

2.087 x 2.087 X .7854 = 3.421

334 / 3.421 = 97.632 cfm.  Per sq. inch of valve area

You can use pi x r squared as well.

Cheers guys 

[Martin]

you have to also work out the area of the valve stem and take that away.

i'll put my calculation on when I'm back at work


do the math again.


The heads that Pat did for me are fantastic out stripping anything else we have tested though the range.

and the valve job is as good as it gets, shown by the high flow numbers at low lift

[Martin]

I got the maths for you K-Rock

you dont use the valve size for the area you use the valve seat dia, as this is the last restriction to the flow, less the area of the valve stem.  the reason you cant use the valve size for the area, is that at full lift the valve is out of the way and the seat is the last restriction .

CB inlet Area      
                                        area
Seat Dia           1.897            2.826527439
Valve Stem     0.341            0.091332911
                           area=   2.735194528

[K-Roc]

I got the maths for you K-Rock

you dont use the valve size for the area you use the valve seat dia, as this is the last restriction to the flow, less the area of the valve stem.  the reason you cant use the valve size for the area, is that at full lift the valve is out of the way and the seat is the last restriction .

CB inlet Area      
                                        area
Seat Dia           1.897            2.826527439
Valve Stem     0.341            0.091332911
                           area=   2.735194528

OK Martin, im with you on your calcs... You didn't specify the seat area or the window area in your original post on the numbers.  I thought you were just going off the the raw valve diameter.  ( FYi that is how we measure the basic number it over here ...  valve diameter... buts it's just a coefficient to use as you work the port.

If I am fully mapping a port I use the seat throat area and  window area at .050" lift increments and base my work off of that.

 Pat did an awesome job on those ports,  ( as he has done on several of his designs ) The flow numbers are right up there with any advanced wedge head in flow per Sq inch.

I have not measured any velocities on these heads but with an average cross sectional area of your port it would be pretty easy to get really close with some more math.

How big is your motor? And what RPMS are you turning?

cheers.

[Martin]

we are doing a velocity map of the ports this week.

my motor is 2.8 ltr we spin it up to 9K