what determines low-end torque for heads?
09-30-2006, 03:48 PM
#1
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what determines low-end torque for heads? Want a set a of heads with strong torque down low, besides milling and bumping compression, what boosts low-end power for a 236/236 cam. Any suggestions for heads, don't think ls6 heads will give me that low-end as well as ported 5.3s or pp241s.suggestions?
09-30-2006, 08:43 PM
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I'm keeping this size cam, what heads? not camshaft. LS6 heads are out of the question for what I want, ideally some home-ported 241s would be best for low-end torque and mileage but in terms of machine ported heads such as patriot 5.3s or AFRs 205, which would be best, any other suggestions?
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10-01-2006, 09:55 AM
#10
High velocity small runner heads will aid filling at lower rpm. This will give you more torque in the low and mid-range. This is one of the reasons why the DART, PRC and AFR heads in the 205cc runner configuration are so lethal.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
10-01-2006, 10:10 AM
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like Patrick said,small runners to boost velocity.there's nothing wrong with going with a set of LS6 heads for what you want.they would be a little better,IMO because they have a more efficient combustion chamber than 241s.the proper cross section of the runners for your target rpm is key,not just port volume....FWIW,my intake ports come in at about 216cc.matches my cam perfectly.
10-01-2006, 01:35 PM
#12
Originally Posted by Patrick G
High velocity small runner heads will aid filling at lower rpm. This will give you more torque in the low and mid-range. This is one of the reasons why the DART, PRC and AFR heads in the 205cc runner configuration are so lethal.
10-01-2006, 01:56 PM
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Long ago, I would have piped up and said small cross sectional area will give high velocity and promote better cylinder filling, so go with a 205cc head. This is why I bought the Dart 205s when they came out.
BUT if you consider how well the CNC LS6 heads are performing it perplexes me. They are making more power than stock below peak torque and not destroying drivability ALL WITH 240CC INTAKE RUNNERS. I'm actually thinking of buying a set of these now.
Ben T.
BUT if you consider how well the CNC LS6 heads are performing it perplexes me. They are making more power than stock below peak torque and not destroying drivability ALL WITH 240CC INTAKE RUNNERS. I'm actually thinking of buying a set of these now.
Ben T.
10-01-2006, 05:07 PM
#14
Small runner heads would seem to work, but wouldn't larger L92's with their great low to mid lift flow numbers work better? Wouldn't the head with the better low to mid lift flow numbers develop more low end torque regardless of port volume?
Lift .200 .300 .400 .500 .550 .600 .Volume
205 .145 .210 .257 .290 .301 .308 205 ccs...(205 w/ 4.125 #s)
L92...153...225....277...313....326...335......Lar ger cc's 240+
Lift .200 .300 .400 .500 .550 .600 .Volume
205 .145 .210 .257 .290 .301 .308 205 ccs...(205 w/ 4.125 #s)
L92...153...225....277...313....326...335......Lar ger cc's 240+
Last edited by gollum; 10-01-2006 at 05:26 PM.
10-01-2006, 07:16 PM
#16
Originally Posted by 98camaroLS1M6
Want a set a of heads with strong torque down low, besides milling and bumping compression, what boosts low-end power for a 236/236 cam. Any suggestions for heads, don't think ls6 heads will give me that low-end as well as ported 5.3s or pp241s.suggestions?
I'm keeping this size cam, what heads? not camshaft. LS6 heads are out of the question for what I want, ideally some home-ported 241s would be best for low-end torque and mileage but in terms of machine ported heads such as patriot 5.3s or AFRs 205, which would be best, any other suggestions?
As for the heads, PP 5.3 heads are getting excellent flow from a smaller volume than the LS6 style heads. These are a great budget head. Personally though, I would look at AFR 205's long and hard before making a decision.
quote from the Best Cam for the Street thread
Originally Posted by PREDATOR-Z
Best all around street cam is in the 224/228 range anything more and you're relinquishing low-midrange for upper rpm power.
You do not need big to make street killer combos, you need the right SCR/DCR motor combo.
BTW DD is a relative terms, some like a eye watering overlap monster and some like nervous high lift Stealth. It up to you and your taste.
To make it easy for you, if you are going cam only, the get a cam that makes a good 8.5 DCR with the stock compression, with that in mind the highest Duration that will achieve that. Then it is just a matter of choosing the lifts you are comfy with (LOBE choice). There is your good street cam. (no sticky tires, super high stall etc...)
You do not need big to make street killer combos, you need the right SCR/DCR motor combo.
BTW DD is a relative terms, some like a eye watering overlap monster and some like nervous high lift Stealth. It up to you and your taste.
To make it easy for you, if you are going cam only, the get a cam that makes a good 8.5 DCR with the stock compression, with that in mind the highest Duration that will achieve that. Then it is just a matter of choosing the lifts you are comfy with (LOBE choice). There is your good street cam. (no sticky tires, super high stall etc...)
10-01-2006, 07:17 PM
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like i posted earlier,it's not just the port volume,but also the cross section of the port that will affect velocity.the GMPP/LPE LS6 head is a good example of this.huge port volume compared to the new heads out there,but they won't kill low end TQ.....
10-02-2006, 02:48 AM
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Originally Posted by Studytime
Long ago, I would have piped up and said small cross sectional area will give high velocity and promote better cylinder filling, so go with a 205cc head. This is why I bought the Dart 205s when they came out.
BUT if you consider how well the CNC LS6 heads are performing it perplexes me. They are making more power than stock below peak torque and not destroying drivability ALL WITH 240CC INTAKE RUNNERS. I'm actually thinking of buying a set of these now.
Ben T.
BUT if you consider how well the CNC LS6 heads are performing it perplexes me. They are making more power than stock below peak torque and not destroying drivability ALL WITH 240CC INTAKE RUNNERS. I'm actually thinking of buying a set of these now.
Ben T.
Last edited by cantdrv65; 10-02-2006 at 02:55 AM.
10-02-2006, 02:51 AM
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Originally Posted by gollum
Small runner heads would seem to work, but wouldn't larger L92's with their great low to mid lift flow numbers work better? Wouldn't the head with the better low to mid lift flow numbers develop more low end torque regardless of port volume?
Lift .200 .300 .400 .500 .550 .600 .Volume
205 .145 .210 .257 .290 .301 .308 205 ccs...(205 w/ 4.125 #s)
L92...153...225....277...313....326...335......Lar ger cc's 240+
Lift .200 .300 .400 .500 .550 .600 .Volume
205 .145 .210 .257 .290 .301 .308 205 ccs...(205 w/ 4.125 #s)
L92...153...225....277...313....326...335......Lar ger cc's 240+