head flow-hp
#1377229
01/27/13 07:37 PM
01/27/13 07:37 PM
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Joined: Dec 2008
Posts: 1,285 okla.
sam64
OP
pro stock
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OP
pro stock
Joined: Dec 2008
Posts: 1,285
okla.
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on a 470bb with a mp .590 solid,11.1 comp.,how much hp difference from a head that flows 290@.600 vs 315@.600?thanks,sam.
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Re: head flow-hp
[Re: BIGSPEED]
#1377235
01/28/13 03:29 AM
01/28/13 03:29 AM
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Joined: Jun 2003
Posts: 9,225 Charleston
sixpackgut
Drag Week Mod Champion
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Drag Week Mod Champion
Joined: Jun 2003
Posts: 9,225
Charleston
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I would compare the .550 numbers
Gen 3 power 6.22@110, 9.85@135 Follow @g3hemiswap on instagram
performance only racing, CRT, ultimate converter, superior design concepts, ThumperCarbs
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Re: head flow-hp
[Re: sam64]
#1377238
01/29/13 12:47 PM
01/29/13 12:47 PM
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Joined: Jan 2013
Posts: 167 maryland
74yellowduster
member
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member
Joined: Jan 2013
Posts: 167
maryland
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Quote:
on a 470bb with a mp .590 solid,11.1 comp.,how much hp difference from a head that flows [Email]290@.600[/Email] vs [Email]315@.600?thanks[/Email],sam.
hmmm... i wouldnt recommend pulling heads just to do a port job...
are they irons? what heads?
what i would do, is shop around, lurk the boards find a top end for sale / heads intake
get offsets on them... heads ported at the same time. so your .590 lift becomes .630 and you have fresh springs/valves etc ready to go.
that would make a big difference. also if you go from 11.12 down to 10 something you may need to do some other work to stay legal. you could do some lightening as well and you will be down in the 10's
do it as an upgrade package... that way you can keep racing as you lurk and gather parts, and you will notice a much bigger change.
just taking your current heads off and having them ported and putting them back on is a ton of work & downtime with not as much return on your dollar
if you already have alum heads you could resell those
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Re: head flow-hp
[Re: pittsburghracer]
#1377239
01/29/13 02:20 PM
01/29/13 02:20 PM
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Joined: Feb 2003
Posts: 12,675 Columbia, CT
moper
I Live Here
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I Live Here
Joined: Feb 2003
Posts: 12,675
Columbia, CT
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Quote:
Quote:
on a 470bb with a mp .590 solid,11.1 comp.,how much hp difference from a head that flows [Email]290@.600[/Email] vs [Email]315@.600?thanks[/Email],sam.
There is not a real simple answer to that question. By the time you subtract valve lash, pushrod deflection, and a few other factors your 590 lift cam is not 590. When porting a set of heads they should be customized to match the customers combo. It is real easy to reach for that high flow number only to have mid lift numbers and air-speed suffers. Most guys use the simple factor of 2hp per 1 cfm but a lot of things come into play.
x3
Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.
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Re: head flow-hp
[Re: 74yellowduster]
#1377240
01/29/13 03:06 PM
01/29/13 03:06 PM
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Joined: Dec 2008
Posts: 1,285 okla.
sam64
OP
pro stock
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OP
pro stock
Joined: Dec 2008
Posts: 1,285
okla.
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Quote:
Quote:
on a 470bb with a mp .590 solid,11.1 comp.,how much hp difference from a head that flows [Email]290@.600[/Email] vs [Email]315@.600?thanks[/Email],sam.
hmmm... i wouldnt recommend pulling heads just to do a port job...
are they irons? what heads?
what i would do, is shop around, lurk the boards find a top end for sale / heads intake
get offsets on them... heads ported at the same time. so your .590 lift becomes .630 and you have fresh springs/valves etc ready to go.
that would make a big difference. also if you go from 11.12 down to 10 something you may need to do some other work to stay legal. you could do some lightening as well and you will be down in the 10's
do it as an upgrade package... that way you can keep racing as you lurk and gather parts, and you will notice a much bigger change.
just taking your current heads off and having them ported and putting them back on is a ton of work & downtime with not as much return on your dollar
if you already have alum heads you could resell those
the motor is a new build to replace the grenaded 440,the heads are the mopar eddies that came off the 440,been touched up not ported,car weighes 3250 race ready.probably run them as is this year,only 4 weeks till track opens.
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Re: head flow-hp
[Re: sam64]
#1377241
01/29/13 03:34 PM
01/29/13 03:34 PM
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Joined: Aug 2003
Posts: 43,315 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,315
Bend,OR USA
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My first set of Eddy RPM flowed 288 CFM at .600 on the intake on one head and 286 on another intake port on the other head on a Super Flow 600 bench at 28. inches of water. I sent them to Jeff at Modern Cylinder heads for his CNC port job, they flowed 317 at .600 on his bench and 310 on the same Super Flow bench as before. I'm sure those heads made close to 60 HP more on the motor, I ended up swapping the old rocker arms out, Chinese brand 1.6 ratio CAT aluminum roller rockers with 1.52 actual ratio to a set of Harland Sharp full roller rockers that are 1.6 ratio advertised ratio that are 1.65 actual ratio at the retainers My Duster picked up right at 4 MPH(124.5 to 128.6) and close to .25 ET (10.69 to 10.43)in the 1/4 mile with the new heads and rockers I built a bracket 470 C.I. 440 motor for a customer and freind four years ago that had a set of B1-BS heads that I had Jeff at MCH CNC port to M.W. size, they flowed 350 CFM at .600 and a little more at .700 and .800. That motor had right at 12.8 to 1 compression ratio and made 720 HP at 7000 RPM with a used M.W. port sizes sheet metal tunnel ram with two Holley 750 D.P. carbs on it The cam was a custom grind Crane solid rolleer that had symetrical lobes, 273 at .050 and .430 lobe lifts, gold Crane 1.5 extruded aluminum rockers with roller tips.IHTHs
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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