My turn for cam help - street/open track LS6 in CTS-V
11-08-2011, 10:43 PM
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My turn for cam help - street/open track LS6 in CTS-V A few months ago the stock engine in my '05 CTS-V let go during a track event at VIR. (Video can be seen on youtube - just search for LS6 failure VIR or something along those lines.) After a couple weeks of searching, I was able to find a new, factory LS6 long block from www.newgmengines.com. My intention was to stick with an LS6, with some moderate upgrades to make a bit more power while hopefully maintaining good durability. The car splits daily driver duties with my Subaru and is my vehicle of choice for road trips, so I wasn't looking to create a gas drinking, fire-breathing monster.
I pulled the heads off the dead engine and sent them off to TEA. They were able to fix the damaged #5 combustion chamber, and replaced valves in #5 and #6, then did their "stage 1" porting and a valve job. Valves are stock (hollow stem and sodium filled), springs are beehive PAC 1518s.
Head flow numbers:
Lift . . . . . . . Int CFM . . . . . Exh CFM
0.100 . . . . . . 67.7 . . . . . . . 58.2
0.200 . . . . . . 144.9 . . . . . . 119.4
0.300 . . . . . . 213.6 . . . . . . 175.0
0.400 . . . . . . 254.5 . . . . . . 218.1
0.500 . . . . . . 292.3 . . . . . . 240.0
0.550 . . . . . . 304.2 . . . . . . 247.7
0.600 . . . . . . 314.2 . . . . . . 252.0
I also picked up a used, unported FAST 90/92 intake manifold from the classifieds here, and will be picking up a 90mm throttle body. The car already has Kooks 1-3/4" long tubes with cats.
So, now it's time for a cam choice. A fellow V owner, who also open tracks his car, has the EPS 222/226 cam in his car and has been very happy with that. He wanted to keep lift under 0.600 to promote valvetrain longevity, which seems like a good idea considering how much time the engine will spend at elevated RPMs on track. He's got an LS2, so a bit of extra displacement compared to my LS6, but I don't know how much of a difference that would make for cam selection.
Should I just follow his lead with the EPS cam, or what other options I should look at (and why)? I've had Ed Curtis do two cams for my Mustang (first a blown 302, then a N/A 351W), but I've never had that car on a dyno in the 17-1/2 years I've owned it, and I have no baseline to compare to, so I can't say whether the custom cam was worth the effort or not. My inclination is to think that with all the OTS LS cam options out there, chances are there's something that will fit the bill without having to go custom. However, I can easily afford to go custom if it's the right answer.
Thanks for your time and comments!
I pulled the heads off the dead engine and sent them off to TEA. They were able to fix the damaged #5 combustion chamber, and replaced valves in #5 and #6, then did their "stage 1" porting and a valve job. Valves are stock (hollow stem and sodium filled), springs are beehive PAC 1518s.
Head flow numbers:
Lift . . . . . . . Int CFM . . . . . Exh CFM
0.100 . . . . . . 67.7 . . . . . . . 58.2
0.200 . . . . . . 144.9 . . . . . . 119.4
0.300 . . . . . . 213.6 . . . . . . 175.0
0.400 . . . . . . 254.5 . . . . . . 218.1
0.500 . . . . . . 292.3 . . . . . . 240.0
0.550 . . . . . . 304.2 . . . . . . 247.7
0.600 . . . . . . 314.2 . . . . . . 252.0
I also picked up a used, unported FAST 90/92 intake manifold from the classifieds here, and will be picking up a 90mm throttle body. The car already has Kooks 1-3/4" long tubes with cats.
So, now it's time for a cam choice. A fellow V owner, who also open tracks his car, has the EPS 222/226 cam in his car and has been very happy with that. He wanted to keep lift under 0.600 to promote valvetrain longevity, which seems like a good idea considering how much time the engine will spend at elevated RPMs on track. He's got an LS2, so a bit of extra displacement compared to my LS6, but I don't know how much of a difference that would make for cam selection.
Should I just follow his lead with the EPS cam, or what other options I should look at (and why)? I've had Ed Curtis do two cams for my Mustang (first a blown 302, then a N/A 351W), but I've never had that car on a dyno in the 17-1/2 years I've owned it, and I have no baseline to compare to, so I can't say whether the custom cam was worth the effort or not. My inclination is to think that with all the OTS LS cam options out there, chances are there's something that will fit the bill without having to go custom. However, I can easily afford to go custom if it's the right answer.
Thanks for your time and comments!
Last edited by AAIIIC; 11-09-2011 at 08:06 AM. Reason: EPS cam typo
