[Z06] GMPP stage 3 cam, will I have piston to valve clearance issues on a stock LS7?
11-10-2016, 04:02 PM
#41
Team Owner
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.
11-10-2016, 04:07 PM
#42
Instructor
Thread Starter
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.
So the question is even more relevant now.
11-10-2016, 04:24 PM
#43
Instructor
Thread Starter
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.
11-10-2016, 05:29 PM
#44
Le Mans Master
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.
11-10-2016, 05:51 PM
#45
Supporting Vendor
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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.
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.
11-11-2016, 03:02 AM
#46
Instructor
Thread Starter
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.
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.
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.
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.
11-11-2016, 01:14 PM
#47
Team Owner
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
Are these the correct retainers:
http://www.briantooleyracing.com/sr0...set-of-16.html
As for the retainers, I would email BTR to ensure you have the proper ones for your application.
11-12-2016, 04:22 AM
#48
Instructor
Thread Starter
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.
As for the retainers, I would email BTR to ensure you have the proper ones for your application.
01-10-2017, 04:57 PM
#49
Instructor
Thread Starter
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?"
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?"
01-10-2017, 05:41 PM
#50
Melting Slicks
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 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
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