Re: OEM Cast Iron HEMI Cylinder heads: Flow Numbers
[Re: domingo]
#1497325
09/06/13 09:12 PM
09/06/13 09:12 PM
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Joined: Jan 2003
Posts: 75,318
A gulag near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,318
A gulag near you.
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Quote:
Pure stock HEMI cars run in the 11s!!!!!
Stock stroke, stock cam specs, no porting, full exhaust, I believe 11:1 max compression, stock tires.
Pure stock engines that run faster than they did when new are built to NHRA specs , I don't know the specs on a hemi but it wouldn't surprise me to see the compression closer to 12.0 vs. the factory advertised 10.25
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Re: OEM Cast Iron HEMI Cylinder heads: Flow Numbers
[Re: JohnRR]
#1497326
09/06/13 09:26 PM
09/06/13 09:26 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Quote:
Pure stock HEMI cars run in the 11s!!!!!
Stock stroke, stock cam specs, no porting, full exhaust, I believe 11:1 max compression, stock tires.
Pure stock engines that run faster than they did when new are built to NHRA specs , I don't know the specs on a hemi but it wouldn't surprise me to see the compression closer to 12.0 vs. the factory advertised 10.25
Pure stock and Factory stock allow 1.5 points higher for compression ratio over stock advertised. So, a street hemi can legally go up to 11.75:1.
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Re: OEM Cast Iron HEMI Cylinder heads: Flow Numbers
[Re: domingo]
#1497328
09/06/13 09:42 PM
09/06/13 09:42 PM
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Joined: Jan 2006
Posts: 419
NY
F1Scamp
mopar
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mopar
Joined: Jan 2006
Posts: 419
NY
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Boy I guess that's why I feel like anybody running a Hemi is taking the easy way out...
Work In Progress- 71' Duster F.A.S.T.- 10.36@130 Smallblock Record Holder.
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Re: OEM Cast Iron HEMI Cylinder heads: Flow Numbers
[Re: domingo]
#1497329
09/06/13 09:42 PM
09/06/13 09:42 PM
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Joined: May 2004
Posts: 12,488
Taxes & Virus's R-US, NY
Dragula
I Live Here
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I Live Here
Joined: May 2004
Posts: 12,488
Taxes & Virus's R-US, NY
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Quote:
Pure stock HEMI cars run in the low 10s!!!!!
Stock stroke, stock cam specs, no porting, full exhaust, I believe 11:1 max compression, stock tires.
Fixed that for you...
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Re: OEM Cast Iron HEMI Cylinder heads: Flow Numbers
[Re: DusterDave]
#1497332
09/06/13 11:57 PM
09/06/13 11:57 PM
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Joined: Jan 2003
Posts: 9,672
Lima, Peru
domingo
OP
EL Master
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OP
EL Master
Joined: Jan 2003
Posts: 9,672
Lima, Peru
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Quote:
Quote:
Good luck with your quest,I was never able to leave anything "stock" 
 I'm the same way! It is physically impossible for me to leave anything bone stock.
Thats why Im in a struggle with myself on wether leaving it stock stroke or using the 4.15 stroker kit I have on the shelf....
I wont be able to use 11.7:1 compression because gasoline down here is CRAPPY.
I would be limited to run only up to 10:1 with the cast iron heads and the local pump gas....
My stroker kit will yield just shy of 10:1
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Re: OEM Cast Iron HEMI Cylinder heads: Flow Numbers
[Re: dogdays]
#1497334
09/08/13 10:05 AM
09/08/13 10:05 AM
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Joined: Jan 2003
Posts: 9,672
Lima, Peru
domingo
OP
EL Master
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OP
EL Master
Joined: Jan 2003
Posts: 9,672
Lima, Peru
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Quote:
I'm going to try to make this simple. Your stock head flow numbers are good for at least 700 hp.
Getting 700 hp from a naturally aspirated 426 requires rpm in the stratosphere. You pay out the nose for valvetrain, etc.
The 426 was the direct result of NASCAR's 7-liter rule.
So they made the best heads they could, but the displacement was limited by the rule. Result is an engine with way too much cylinder head for its size.
You don't have a 7 liter rule. Build the biggest shortblock you can afford. Then it'll make the hp at a more usable rpm.
It just makes sense.
R.
Yes that is totally right, only thing is I might consider the idea of shipping this car over to the states so I can keeo it there and Id love to participate in the pure stock drags...it would be killer.
Now on the other hand....
Yes, if I were to keep it here what makes the most sense is just to build it for pump gas use and put a 4.15 stroker kit in it.....which I already have, for a compression just shy of 10:1
decisions, decisions, decisions.....
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Re: OEM Cast Iron HEMI Cylinder heads: Flow Numbers
[Re: domingo]
#1497335
09/08/13 01:35 PM
09/08/13 01:35 PM
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Joined: Jan 2003
Posts: 2,936
Finalnd, Perkele
jyrki
master
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master
Joined: Jan 2003
Posts: 2,936
Finalnd, Perkele
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Hemi heads have a tendency of doing well in a flow bench, however it seems to be way more difficult to get out power that equals the flow capacity.
Whatkind of gas you have over there, how is it rated?
Plynouth VIP '67 TT IC EFI
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Re: OEM Cast Iron HEMI Cylinder heads: Flow Numbers
[Re: domingo]
#1497337
09/08/13 02:11 PM
09/08/13 02:11 PM
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Joined: Jan 2003
Posts: 2,936
Finalnd, Perkele
jyrki
master
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master
Joined: Jan 2003
Posts: 2,936
Finalnd, Perkele
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So you have it rated the same way as here. We had over 12:1 agt best, but the cams had pretty huge degrees adn other things were decently scienced out too. Since it's not practical to go overboard I would keep teh CR "safe" and choose the other parts, mainly the cam, accordingly. If you want more detonation resistance, add 5-10% toluene to your gas!
Plynouth VIP '67 TT IC EFI
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