Head CFM vs Horsepower

[Mike Gaines]

For those guys who are running low 10's and high to mid 9's (and maybe even lower) what kind of CFM do your heads flow ?
I have out of the box INDY SEZ heads standard port (non-max wedge size) that only flow 290CFM and have talked to Hughes about porting them to Max Wedge with either 350CFM or the full port program which takes them out to 370CFM.(both jobs include unshrouding the valves) The 350CFM is $995 and the 370CFM is $1470 (which includes extra Exhaust Port Work)
I want to go from 10.60ET to around 10.25 ET.
Also with either of the above porting jobs I guess I would need to upgrade my headers from 1 7/8 (3" collectors) to 2" (3.5 collectors).
Your thoughts and educated opinions from your experiences would be appreciated.

 

[moparcrazy]

Hello Mike Nice talking with you the other day ! Dude you gotta run TTi's Step header 2" to 2 1/8 with 3.5 collector, Good Luck Bud !!

 

[Tex013]

Mike ,
You will maybe need more than just the head flow . Exhaust , camshaft , intake . You may even need more cubes . Head flow is only part of it , you already know that

Tex

 

[bobtile]

My heads flow 360.
448 CI
solid flat tappet cam
10.11 low et
Light car though. 3085 with me in it.

 

[dvw]

Mine are in the mid 380's. Best ever with Holleys, 9.02@151. During this summer at 85 degrees with Edelbrocks [email protected]. Weight 3350lbs
Doug

 

[Canyon707]

Milke you speed animal. I was thinking the same thing for this winter build. Hope you get some good answers. I will be watching.

 

[rumblefish360]

What is the cars race weight?

 

[cdr]

IMO, do the full port & dont forget to get the intake manifold done, right now you are making good power for your air flow, you will easily pick up what you are wanting, & then some.

 

[66Satellite47]

Mike, head porting by someone that knows what they're doing is the best. You have much potential.

 

[Mike Gaines]

What is the cars race weight?

3640 with me and 5 gal gas.I figure it has to be making around 675HP now to go 10.60 consistant at 126,126

 

[Mike Gaines]

Mike ,
You will maybe need more than just the head flow . Exhaust , camshaft , intake . You may even need more cubes . Head flow is only part of it , you already know that

Tex

I am not changing cam or cuBic inch and my budget only allows Dougs 2" headers not TTI

 

[Budnicks]

try this it may help

http://www.wallaceracing/hpcalculatorquarter.php

more cfm flow = more HP

from that calculator for references purposes, I've used a lot...
anyway; 10.58 @ 126 @ 3640#'s
your hp from ET is "about" 546 @ the rear wheels, 607 @ the flywheel
your hp from your MPH is "about 524 @ the rear wheals, 583 @ the flywheel
{seems the car isn't mph-en' as well as it should for your hp,
too short of tire or too much gear maybe, or too much converter,
not enough camshaft, too small intake valve or runners,
could be a combo of several things, engine wise anyway, just spit-balling}

have you blocked off all air from going under or around the radiator or
under the car ? etc., also fresh cool dense air in to the crab, seal scoop ram air effect
ram air is worth like 10-12 hp @ 100mph, do both/that's usually worth a couple tenths too...

I'd bet there's more et/mph still in the car, where I'm not 100% sure...

IIRC ballpark cfm flow is in relation to hp = 2.06hp:1cfm of flow

you'd need like 610 @ the wheels @ your current weight
so you need another 64 net hp/rear wheels or so ballpark @ your current weight
to go 10.20's

so basically IMO another 30 or so cfm is needed, if everything is perfect

removing weight is a good option too, much times cheaper than making HP...

again just ball-parking #'s, your experiences may vary drastically

-----------------------------------------------------------------------------------------------

for give me it was like 5+ years ago now
I had heads that only flowed like 330-335 cfm std ports RPM Eddys
{ported by Mark Lowe RIP}
Eddy Tarantula Intake {also ported by Mark Lowe}
went best 9.77 @ 135 N/A in 100* Sac. heat unprepared track TnT @ 3520#'s,
only a 479ci w/1050 highly trick Dominator (1350cfm},
CalTracs 315 MT drag radials, 3800 stall {loser than that at the track}
mvb 727tf, 0.690" roller with the Crane gold 1.6 roller rockers
1-7/8" headers into 4-2-1 Scavenger collectors & 3" 16 extensions 4.30:1 gears
{may have been 4:10's/can't remember I tried both,
went to 3.91:1 the to 3.73:1 with N20, ran 8.58 @ 156 on a 300 shot}

high 1.30's 60', low 1.20's 60' on N20, car hooked well,
didn't wheelie as much as your does either...
Only had like 3.5" of free play/lift in the front too
{I know Calvert CalTracs recommends 5"s, it didn't work on my car}
but all tubular Capps Automotive suspension, old revalved Lamb D/A shocks
I can't remember on what settings, it was stiff thou...

went 10.0's dipped down in the hi 9.90's same everything
except heads were ported Stealth's std ports {crap/long story}
& with Out of the box RPM's 84cc just cleaned up/prep for my camshaft
ran 10.03 with a 6bbl muffled, thru Flowmasters out the back,
they {Stealth heads} only flowed like 315cfm IIRC,
Eddys OOTB were rated @ 291cfm int. @ 0.600" gross lift IIRC...

I hope my blabering helps some

good luck & happy Moparing

 

[Budnicks]

Contact Jim LaRoy/IQ52 here...
1st I'd talk with LaRoy Engines {?} Challis Idaho
he does wonders with wedge heads, his son Cody too...

 

[Budnicks]

126mph is good for 10.20's too, if ideal conditions & car works best...

kind of depends on what's done
my cars always et'd better than they mph'd too

that's the name of the game is et,
IMO hp #'s is for bragging rights & dyno sheets

 

[Tex013]

I am not changing cam or cuBic inch and my budget only allows Dougs 2" headers not TTI

I have the dougs sitting in my workshop . I will have exhaust to diff , street car
My budget at the moment says stick with current freshened up heads .
CFM is only good if the rest of the motor can take advantage of it .

Tex

 

[dvw]

126mph is good for 10.20's too, if ideal conditions & car works best...

kind of depends on what's done
my cars always et'd better than they mph'd too

that's the name of the game is et,
IMO hp #'s is for bragging rights & dyno sheets

I used to slow my 63 Polara to run 10.50 index. Always around [email protected]