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[Z06] GMPP stage 3 cam, will I have piston to valve clearance issues on a stock LS7?

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[Z06] GMPP stage 3 cam, will I have piston to valve clearance issues on a stock LS7?

 
Old 11-10-2016, 04:02 PM
  #41  
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Originally Posted by Dan_the_C5_Man View Post
In consideration of the larger cam, maybe go ahead and swap them with the Ferrea.
I second that recommendation...Ferrea F2042p exhaust valves would be an excellent choice. I would also recommend PSI 1515 springs with Ti retainers (BTR makes them for the 1515 spring) for your build.
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Old 11-10-2016, 04:07 PM
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Correction, I went back and checked some old emails and I was one year off, the engine was actually bought in late 2007 so I must have the old exhaust valves then.

So the question is even more relevant now.
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Old 11-10-2016, 04:24 PM
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Originally Posted by MTPZ06 View Post
I second that recommendation...Ferrea F2042p exhaust valves would be an excellent choice. I would also recommend PSI 1515 springs with Ti retainers (BTR makes them for the 1515 spring) for your build.
Thanks for the suggestion, would you please motivate why I should do that? The springs and retainers that is.

Are these the correct retainers:

http://www.briantooleyracing.com/sr0...set-of-16.html

Last edited by EVOVII_SWE; 11-10-2016 at 04:26 PM.
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Old 11-10-2016, 05:29 PM
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Originally Posted by EVOVII_SWE View Post
Correction, I went back and checked some old emails and I was one year off, the engine was actually bought in late 2007 so I must have the old exhaust valves then.

So the question is even more relevant now.
You have to appreciate that Katech had some level of involvement with the testing and development of the LS7 platform, so keep that in mind.

That said, the consensus is that the exhaust valve manufacturer increased the inner-wall thickness in the later versions, which would naturally increase component durability. Katech's point is, "with properly machined heads, do you NEED the additional wall thickness"? Considering the relatively low cost to swap them out, it does make good sense to do so.

Last edited by Dan_the_C5_Man; 11-10-2016 at 06:22 PM.
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Old 11-10-2016, 05:51 PM
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I would not run the old style LS7 exhaust valves (the early design).
We cut a bunch of them up a few years ago and they had extreme inconsistencies in wall thickness from one side of the valve to the other.
If you want to run GM sodium exhaust valves go with the late model valves (late 08'+).

EVOVII_SWE:
Responded to your email with parts shipping quote to Sweden.

Last edited by American Heritage; 11-10-2016 at 05:51 PM.
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Old 11-11-2016, 03:02 AM
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Originally Posted by Dan_the_C5_Man View Post
You have to appreciate that Katech had some level of involvement with the testing and development of the LS7 platform, so keep that in mind.

That said, the consensus is that the exhaust valve manufacturer increased the inner-wall thickness in the later versions, which would naturally increase component durability. Katech's point is, "with properly machined heads, do you NEED the additional wall thickness"? Considering the relatively low cost to swap them out, it does make good sense to do so.
Originally Posted by American Heritage View Post
I would not run the old style LS7 exhaust valves (the early design).
We cut a bunch of them up a few years ago and they had extreme inconsistencies in wall thickness from one side of the valve to the other.
If you want to run GM sodium exhaust valves go with the late model valves (late 08'+).

EVOVII_SWE:
Responded to your email with parts shipping quote to Sweden.
Thanks, I'll look into the valves
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Old 11-11-2016, 01:14 PM
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Originally Posted by EVOVII_SWE View Post
Thanks for the suggestion, would you please motivate why I should do that? The springs and retainers that is.

Are these the correct retainers:

http://www.briantooleyracing.com/sr0...set-of-16.html
Spintron testing has shown PSI beehives to have more control over the valvetrain at higher RPM's in LS7's. The PSI 1511 is a great spring and I run them in my C6Z, but its still on a stock cam. While the 1511's work well with aftermarket cams (Katech uses them in their builds), the 1515 spring was developed for the LS7 with a high lift cam. http://www.briantooleyracing.com/650...e-springs.html

As for the retainers, I would email BTR to ensure you have the proper ones for your application.
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Old 11-12-2016, 04:22 AM
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Originally Posted by MTPZ06 View Post
Spintron testing has shown PSI beehives to have more control over the valvetrain at higher RPM's in LS7's. The PSI 1511 is a great spring and I run them in my C6Z, but its still on a stock cam. While the 1511's work well with aftermarket cams (Katech uses them in their builds), the 1515 spring was developed for the LS7 with a high lift cam. http://www.briantooleyracing.com/650...e-springs.html

As for the retainers, I would email BTR to ensure you have the proper ones for your application.
Thank you for the information. I'll look into it
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Old 01-10-2017, 04:57 PM
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So, the engine is finally back together again with new valve guides and everything to support the cam

It will be mapped when temperatures starts to rise again after winter, very exited to see the results on the dyno and I hope I can live with the driveability of that cam.

A short clip of one of the first startups, it sure sounds nice to me but it depends on perspective, my girlfriend said "is it broken?"

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Old 01-10-2017, 05:41 PM
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Originally Posted by EVOVII_SWE View Post
So, the engine is finally back together again with new valve guides and everything to support the cam

It will be mapped when temperatures starts to rise again after winter, very exited to see the results on the dyno and I hope I can live with the driveability of that cam.

A short clip of one of the first startups, it sure sounds nice to me but it depends on perspective, my girlfriend said "is it broken?"

https://youtu.be/xacf0iphmWg
It sounds great
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