Head flow number question. Post your info here.
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6600 rpm clutch dump of death Administrator
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From: Texas
Re: Head flow number question. Post your info here. One other question. Anyone have any idea what the flow numbers pick up with just installing bigger valves.
One thing I had thought about was a set of LS6 CNC heads and installing a set of 2.055/1.600 valves or even the 2.080s.
I figured it couldn't hurt, especially on the higher lift numbers.
One thing I had thought about was a set of LS6 CNC heads and installing a set of 2.055/1.600 valves or even the 2.080s.
I figured it couldn't hurt, especially on the higher lift numbers.
Thread Starter
6600 rpm clutch dump of death Administrator
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From: Texas
Re: Head flow number question. Post your info here. Never mind, I found my own answer...
https://ls1tech.com/ubb/cgi-bin/ulti...c;f=1;t=006475
<quote>
Also you
should note these numbers are with the stock diameter valves. We have flowed
heads in back-to-back comparisons with larger intake valves that will not
flow any more air than these and in some cases less. Port design, velocity
past the valve, and flow quality are all very important features when
evaluating cylinder head flow. Let's face it, GM has a bigger bank account
to R&D head flow than all of us put together. They have done their homework
on this head.
</quote>
https://ls1tech.com/ubb/cgi-bin/ulti...c;f=1;t=006475
<quote>
Also you
should note these numbers are with the stock diameter valves. We have flowed
heads in back-to-back comparisons with larger intake valves that will not
flow any more air than these and in some cases less. Port design, velocity
past the valve, and flow quality are all very important features when
evaluating cylinder head flow. Let's face it, GM has a bigger bank account
to R&D head flow than all of us put together. They have done their homework
on this head.
</quote>
Thread Starter
6600 rpm clutch dump of death Administrator
Joined: Dec 2001
Posts: 4,983
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From: Texas
Re: Head flow number question. Post your info here. I have updated my spreadsheet with the new information.
Silver Surfer and Chris ARE 360, I have not included your data since it only contains one data point... <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> But thanks for the info. Both heads have some very nice numbers.
<img src="http://www.z06vette.com/gallery/data/1067headflow2.jpg" alt=" - " />
JPR - You stated "1 cfm is worth .27 horsepower " in your post. Is that .27 HP per CFM per port.
I was just trying to quantify some numbers. I.E. a 10 CFM difference between two heads is (.27*10)=2.7 * 8 cyl = 21.6HP
Phil - Which shop do you work at in Houston?
<small>[ September 18, 2002, 06:49 AM: Message edited by: J-Rod ]</small>
Silver Surfer and Chris ARE 360, I have not included your data since it only contains one data point... <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> But thanks for the info. Both heads have some very nice numbers.
<img src="http://www.z06vette.com/gallery/data/1067headflow2.jpg" alt=" - " />
JPR - You stated "1 cfm is worth .27 horsepower " in your post. Is that .27 HP per CFM per port.
I was just trying to quantify some numbers. I.E. a 10 CFM difference between two heads is (.27*10)=2.7 * 8 cyl = 21.6HP
Phil - Which shop do you work at in Houston?
<small>[ September 18, 2002, 06:49 AM: Message edited by: J-Rod ]</small>
TECH Fanatic
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From: New Jersey
Re: Head flow number question. Post your info here. The CFM * .27 calculation is as if you removed a set of heads from say a stock cammed car without any other improvements besides intake airflow inmprovement and that flows porpotional to it's runner size, if you port in a 30 cfm improvement than you will have app 8.1 hp per cylinder * 8 which equals roughly 64 (perfect world) additonal flywheel horsepower providing all the air flow management is optimal. The above calculation is an air flow number which doesn't include a cam dynamic or an intake manifold installed so the raw data number must be calculated off the flow bench with all air management parts to have a more accurate number.
Joe.
Joe.
Launching!
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From: Houston
Re: Head flow number question. Post your info here. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by J-Rod:
<strong>I have updated my spreadsheet with the new information.
Phil - Which shop do you work at in Houston?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">He works at Speedaholic! in houston.
<strong>I have updated my spreadsheet with the new information.
Phil - Which shop do you work at in Houston?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">He works at Speedaholic! in houston.
FormerVendor
Joined: Nov 2001
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From: Dallas/Wylie Texas
Re: Head flow number question. Post your info here. Our LG Motorsports G5 heads flow the following:
@ 28"
LS1 307cfm @ .550 2.02/160 (C&C'd)
LS6 314cfm @ .550 2.02/160
LS6 Big Block heads 335cfm @ .600 2.080/160
These numbers were achieved with a very small port volume. That is what gives our package the high rwtq numbers and good mid range.
@ 28"
LS1 307cfm @ .550 2.02/160 (C&C'd)
LS6 314cfm @ .550 2.02/160
LS6 Big Block heads 335cfm @ .600 2.080/160
These numbers were achieved with a very small port volume. That is what gives our package the high rwtq numbers and good mid range.
Thread Starter
6600 rpm clutch dump of death Administrator
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From: Texas
Re: Head flow number question. Post your info here. Hi Lou,
Good to hear from you. Do you have a complete flow sheet for your heads I&E so that I can add it to the sheet, and what they were flowed at 28" or 25" and the orifice size?
Thanks for your response.
Good to hear from you. Do you have a complete flow sheet for your heads I&E so that I can add it to the sheet, and what they were flowed at 28" or 25" and the orifice size?
Thanks for your response.
Thread Starter
6600 rpm clutch dump of death Administrator
Joined: Dec 2001
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From: Texas
Re: Head flow number question. Post your info here. Thnaks to Jason99TA I have added the stock LS6 heads and the 6.0l heads. I have moved the comparison from the CNC LS6 to the stock LS6. Now the sheet show the flow difference between a stock LS6 head vs everything else.
If someone can get me a stock ls1 I will put that in as the basline.
Jason99TA if you can get one like that for an ls1 I would appreciate it. If you have any sheets done on the same bench for any other LS1 haeds from other tuners, etc... Please post them.
<img src="http://www.z06vette.com/gallery/data/1067headflow4.jpg" alt=" - " />
<small>[ September 20, 2002, 02:45 PM: Message edited by: J-Rod ]</small>
If someone can get me a stock ls1 I will put that in as the basline.
Jason99TA if you can get one like that for an ls1 I would appreciate it. If you have any sheets done on the same bench for any other LS1 haeds from other tuners, etc... Please post them.
<img src="http://www.z06vette.com/gallery/data/1067headflow4.jpg" alt=" - " />
<small>[ September 20, 2002, 02:45 PM: Message edited by: J-Rod ]</small>
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Re: Head flow number question. Post your info here. GTP Stage II 4.8L Heads
Peak numbers
Intake- 307cfm
exhaust-219 cfm
Low lift numbers strictly confidential <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Peak numbers
Intake- 307cfm
exhaust-219 cfm
Low lift numbers strictly confidential <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Re: Head flow number question. Post your info here. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by J-Rod:
<strong>
If someone can get me a stock ls1 I will put that in as the basline.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Production LS1 Aluminum Head
<img src="http://64.14.193.106/p104803_image_small.jpg" alt=" - " />
That's from Chevy High Performance
Bret
<strong>
If someone can get me a stock ls1 I will put that in as the basline.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Production LS1 Aluminum Head
<img src="http://64.14.193.106/p104803_image_small.jpg" alt=" - " />
That's from Chevy High Performance
Bret
Re: Head flow number question. Post your info here. These numbers are from the Flow Pro sheet from TEA for my 5.3L Stage II heads
Lift Intake Exhaust
0.1 69.0 52.9
0.2 139.4 107.8
0.3 201.3 160.7
0.4 251.6 200.7
0.5 287.8 231.2
0.55 298.2 241.3
0.6 299.9 251.0
Lift Intake Exhaust
0.1 69.0 52.9
0.2 139.4 107.8
0.3 201.3 160.7
0.4 251.6 200.7
0.5 287.8 231.2
0.55 298.2 241.3
0.6 299.9 251.0
TECH Apprentice
Joined: Nov 2001
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From: NJ
Re: Head flow number question. Post your info here. a little update on the GM CNC heads i had the intake runners poured and they were 250cc's <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
Jay
www.jayfisherpontiac.com
Jay
www.jayfisherpontiac.com
Staging Lane
Joined: Jul 2002
Posts: 57
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From: La, Ca
Re: Head flow number question. Post your info here. I recently purchased a set of the GM CNC LS6 heads to be installed with an ATI D1SC. Can anyone give recommended cam profile for these heads-coil bind is at .560". <img border="0" alt="[Corvette]" title="" src="graemlins/corvette.gif" />
Re: Head flow number question. Post your info here. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> a little update on the GM CNC heads i had the intake runners poured and they were 250cc's </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I thought I read on a previous post that the GM CNC heads were machined by Lingenfelter. I recently cc'd the intake runner on a pair of LPE CNC LS6 heads and found them to be 252cc. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
While they showed nice midlift flow, they were not very impressive at peak flow (314cfm@28" on a 3.9" test bore). Stock LS6 runners typically cc around 210cc. The port area above the short turn on the LPE CNC head is cavernous. Also, the swirl bump has been completly removed.
Good luck,
Richard <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
While they showed nice midlift flow, they were not very impressive at peak flow (314cfm@28" on a 3.9" test bore). Stock LS6 runners typically cc around 210cc. The port area above the short turn on the LPE CNC head is cavernous. Also, the swirl bump has been completly removed.
Good luck,
Richard <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Moderator
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From: Murrieta
Re: Head flow number question. Post your info here. My stage 3 6.0L heads from Andy's Auto 2.08/1.60" flowed
346/237 @ .600"
I think it's a 58cc combustion chamber (.040 mill 11.2:1 CR, does that sound about right?).
346/237 @ .600"
I think it's a 58cc combustion chamber (.040 mill 11.2:1 CR, does that sound about right?).
TECH Senior Member
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Posts: 10,341
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Re: Head flow number question. Post your info here. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TransAmaniac:
<strong>GTP LS1 I/E
.100 65.8/51.0
.200 135.9/103.8
.300 200.8/141.5
.400 244.1/176.2
.500 278.3/190.4
.550 291.5/194.1
.600 285.0/198.3
.650 291.4/202.7
I/E Ratio @ .550=70%
235cc I port</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That is a pretty big intake port isnt it?
Maybe with their small chamber volume and the big intake port they are making good power.
Cheers,
Chris
<strong>GTP LS1 I/E
.100 65.8/51.0
.200 135.9/103.8
.300 200.8/141.5
.400 244.1/176.2
.500 278.3/190.4
.550 291.5/194.1
.600 285.0/198.3
.650 291.4/202.7
I/E Ratio @ .550=70%
235cc I port</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That is a pretty big intake port isnt it?
Maybe with their small chamber volume and the big intake port they are making good power.
Cheers,
Chris
Re: Head flow number question. Post your info here. This is a very good comparison.. I see some are putting what valves they are using and others are not. A better comparison would be if the heads were all using the same valve sizes.. You agree?
Thread Starter
6600 rpm clutch dump of death Administrator
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From: Texas
Re: Head flow number question. Post your info here. Absolutely, I think valve size is relevant.
For instance MMS Stage II and Stage IIx heads use 2.02.
MTI uses 2.02 only in stage I. Stage II is 2.05 and stage III is 2.080.
For instance MMS Stage II and Stage IIx heads use 2.02.
MTI uses 2.02 only in stage I. Stage II is 2.05 and stage III is 2.080.
Thread Starter
6600 rpm clutch dump of death Administrator
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From: Texas
Re: Head flow number question. Post your info here. Here is the lastest version of the spreadsheet. I need to set up a FTP directory so that I can put a bigger version of this out there. Right ow I am limited to 100K, so it makes the screen caps a bit too small.
<img src="http://www.z06vette.com/gallery/data/1067heads8.jpg" alt=" - " />
<img src="http://www.z06vette.com/gallery/data/1067heads8.jpg" alt=" - " />
Launching!
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From: Bardonia, NY
Re: Head flow number question. Post your info here. Could you possibly cut & paste that data into an excel file for me and e-mail it to XJGPN@aol.com? Thanks.