This has been a subject of other posts on here but I am working on a w9 port design that right now flows upwards of 445@.850" and very near 470@1.00. Velocity down the port is near 325-335 and about 260ish through the throat....port volume around 300cc....still a work in process...

A little over 600 intake & a little over 400 exhaust at 1.1" lift. 2.66 intake and 2.0 exhaust.

https://vimeo.com/44009973

If I remember, my Stage V HEMI (big valve) 517 @.800.

Millennium Hemi

538@.900

245 s are 200 129 , after a touch up
300 202 215
400 260 281
500 305 323
600 334 344
700 330 349 333 with unported intake carb


230 are ported 200 163
300 233
400 300
500 330
600 340
700 340 699 hp 330 676 hp with dom ,spacer,ported intake

Mine are older KB heads. Hopefully my 496 with the help of a 10-71@12 pounds of boost and the right cam it will make around 1100 streetable hp.

Not a typo...I have been working on developing this design for close to 2 years....8/24/10 was the initial flow test. Have made a few more advances since that post.....velocities have improved as has flow...I continue to reiterate that this is a test how....how it will translate to a working port is yet to be determined but the numbers are valid.....have actually recently gotten very close to 470+ albeit it at 1.00" of lift.....at .875" lift the best number to date....and the current...is right around 455. Just to be clear the project is much more than a port job....my intention was to push the limit on the factory parameters of the w9...the port is within the factory external dimensions....no welding, moving of guides or anything of that nature....this model has seen 100's and 100's of hours od grinding, testing, probing and reshaping. What didn't work was redone...epoxied or clayed over and redesigned...what I have now is the result of all that....once I am satisfied with the results I will convert to a fresh port, retest and hopefully find someone to digitize and CNC as I don't think I wish to copy the design to a new set if heads by hand...

How big of a valve, what bore size? Is this a W9RP?

Impressive either way. Good of you to point out these are flow numbers only, not dyno or track times. Hopefully though the big numbers you are getting translate into good results in the car.

No...not RP's....847 castings.....valve is larger than most, 55 degree seat, 95-96% throat....I have no intention of misleading....makes no sense...if I was to purposely inflate or just plain make up numbers the low lift would be better....it is what it is however....but I think the high end makes up for it...heads are designed for a 4.185 bore....actually don't like much larger and will drop in flow if unshrouded too much more....thanks

i still think you need to validate your numbers on another bench and have them post what they are here,,, nobody gets those heads to flow like that up high cause they just arent big enough,, your numbers up to .700 lift are normal or down,,, those heads flatten out past .600 and flatline at .800 usually at 420 or so if real good,,, you getting 470 is crazy good,, and you would need to be big enough to move that much air through,, 95.5 % throat which is huge again,, leaves you like a .020 wide bottom angle,, which usually doesnt work,, but you mention velocities through the throat and then the port,, implying your minimum cross section is 3.00 sq inches of area,, if you have a 2.300 valve in it,, which i dont think will fit in that head,, but you wont say like its super secret,, so ill guess its some huge valve, which is big,, but normal for min area..

i though you said this is going on a street/strip pump gas motor,, if so why focus on airflow from .800 and up?

Again....my bench is calibrated and has been verified against another local bench when the heads were flowing below 400....most of the low lift numbers are very close to what they were then....I do, however, fully intend in having the finished product re-verified. I never mentioned pump gas street/strip and agree that would be assinine. I don't do this to get in pissing contests....I do it because it is what I enjoy and I do it solely for me....I have merely shared my results here as many before me have done...if everyone is only to get the same results as all before them why even bother trying....

I will also say that this particular design is not something that someone will ever accidentally stumble across....it has taken nearly a year of testing and modifying daily to achieve what I have thus far.....part of the reason I choose to keep some aspects to myseld thus far is that even though the flow is great and the velocities are really good does not mean that the particular design will also be conducive to big HP....I hope they will but anyone who does this for hobby.or living will be quick to tell you that in this game sometimes numbers DO lie....

Let me also reiterate that while my bench is calibrated to flow 592cfm in range 6 that is to do so at 25"....if I were deliberately trying to mislead I would base my calculations off of that info....AT THE VERY LEAST...and not bother with the .997 correction factor for flow capacity when flowing at 28".....while not a lot it would gain me some 'flow' but if the numbers aren't genuine I really don't see the point....in the past I had even posted some results that seemed positive BEFORE I verified as I was a bit happy to have them....only to realize why, at that time the gain occurred, and once that issue was corrected and the results proven not actual I deleted that post....I have since ACTUALLY gotten to that point and maybe even a but more but at that time the post was not accurate and was therefore immediately removed....

i am working on some ford d-3 heads for a drag race aplication which will have whatever lift it needs,, probably 1.000 or around there,, 2.250 valve and i need 470 or so cfm,, like what you have,, though my head has a canted intake valve so my mid numbers will be much more than yours,, my peak i hope to get what you have,, im looking to put it on a 373 inch motor that runs to 10,000 and make 1040 hp,, i need a min cross section of 3.75 to do this,, you cannot get that big due to the casting restraints you have,,

if you have airflow,, port cross section to support displacment,, and mixture motion entering the cylinder that all works,, it WILL make power between 2.2-2.4 hp per cfm,, so if you put your motor together and its serious, id expect 1040-1100 hp,, if not,, the head isnt what its supposed to be,, its that easy

that being said,, my 373 inch motor in a 2825lb car,, should go 7.70's with a liberty 5 spd,, making 1040hp at 9600-9800rpm

Mine sometimes flow air with burned fuel and hydrocarbons, and sometimes flow air, just depends on which cycle the engine is on at the time..

LOL

Mine flow 295ish intake and 165ish exhaust so I was told.

Small block indybrock that is basically just cleaned up a tad, and opened up a touch. Runs damn good though!!

Like I have said before.....if theory was law everyone's heads would be perfect and flow exactly the same.....if theory was law porting and cylinder head design would be easy and we would already know all there is to know...

thermo and fluid dynamics are a science....as such...they are not exact, there are exceptions to every rule and what we know today could very well be proven wrong tomorrow.....MCA is just that....the minimum cross sectional area....no one ever said it had to be in any particular place...it could be at the intake flange, the SSR, the throat or the seat....it is merely the part of the port that has the smallest measured cross section...