[Z06] Katech LS7 Valvetrain Dynamics testing approved - seeking input from Corvette Forum
01-11-2013, 02:25 AM
#81
Team Owner
Member Since: Apr 2001
Location: Elmhurst, IL (West Suburb of Chicago) & Home of MEGA Horsepower
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St. Jude Donor '06
The goal is to answer these questions:
Is it safe to run solid exhaust valves with the stock camshaft?
Is it safe to run solid exhaust valves with your typical aftermarket camshaft?
Does switching to a heavier spring with solid exhaust valves have any negative effects?
What is the limiting speed with heavier valves?
Is it safe to run solid exhaust valves with the stock camshaft?
Is it safe to run solid exhaust valves with your typical aftermarket camshaft?
Does switching to a heavier spring with solid exhaust valves have any negative effects?
What is the limiting speed with heavier valves?
01-11-2013, 07:19 AM
#82
Burning Brakes
BTW, I am only interested in steel roller rockers. Aluminum rockers aren't really intended for longevity. Others with experience could comment?
01-11-2013, 08:30 AM
#83
Premium Supporting Vendor
Thread Starter
Wow! Now this is what you call hard core vendor support for the forum and community. Hats off to Jason & Katech
a) Given the test results published in the GM Hi Tech Perf article several years back, I would suggest that #2 and #5 are redundant, unless the cam profile used back then is different from what is proposed now.
b) I wonder if Katech has looked at the PAC 1518 beehive spring; online specs show that it could install at 1.800" for the stock cam (1.140 coil bind) with a seat pressure of 130#, which makes wonder if it might control the heavier solid stainless exhaust valve (even tho the open pressure is less than the PSI) while still providing the advantages of a beehive over a dual. Perhaps that would be worth a test for those that are skittish about the OEM exhaust valve but would like to keep the rest of the valvetrain as light as possible (and keeping the stock cam).
c) Lastly I'm wondering if Katech's FI cam might be added to the mix, especially with the beehive springs, since from what I understand it is designed for the heavier solid stainless valve and again might be an option for those wanting to change valves but keep the rest of the valvetrain light (if none of the beehives are a 'go' for the heavier valve). I have no idea if that would be a suitable grind for an NA car... just a thought.
.
a) Given the test results published in the GM Hi Tech Perf article several years back, I would suggest that #2 and #5 are redundant, unless the cam profile used back then is different from what is proposed now.
b) I wonder if Katech has looked at the PAC 1518 beehive spring; online specs show that it could install at 1.800" for the stock cam (1.140 coil bind) with a seat pressure of 130#, which makes wonder if it might control the heavier solid stainless exhaust valve (even tho the open pressure is less than the PSI) while still providing the advantages of a beehive over a dual. Perhaps that would be worth a test for those that are skittish about the OEM exhaust valve but would like to keep the rest of the valvetrain as light as possible (and keeping the stock cam).
c) Lastly I'm wondering if Katech's FI cam might be added to the mix, especially with the beehive springs, since from what I understand it is designed for the heavier solid stainless valve and again might be an option for those wanting to change valves but keep the rest of the valvetrain light (if none of the beehives are a 'go' for the heavier valve). I have no idea if that would be a suitable grind for an NA car... just a thought.
.
b) Yes, we've used that spring before with the Torquer cam. They worked well, but we chose the PSI because they also performed well and are priced well.
c) It could be used in an NA car. That will be considered.
01-11-2013, 08:32 AM
#84
Le Mans Master
subb'n for some results.
01-11-2013, 08:41 AM
#85
Instructor
Good news. I have received budget approval to run a valvetrain dynamics test for development purposes to prove out a few of the questions posed here on the forum. Before I write the test plan, I'm interested in hearing input from you guys to see if there are additional combinations that need testing. I'm not saying that every combination posted here will get tested, or any additional at all, but your suggestions will be considered.
We would like to run this test as soon as possible. The valvetrain test cell is currently down due to computer problems, but repairs are in progress that should get it back up and running within days. Because it was down there is a bit of a backup of programs that are waiting for testing so we will have to wait in line, but once it gets fixed that should go through smoothly. In other words, I can't guarantee exactly when, but it will get done soon.
Here is how I see the test plan:
1. Stock cam/springs, stock valves
2. Stock cam/springs, solid stainless exhaust valve
3. Stock cam/dual springs, solid stainless exhaust valve
4. Torquer cam/PSI springs, stock valves (already tested long ago, but we will baseline again)
5. Torquer cam/PSI springs, solid stainless exhaust valves
6. Torquer cam/dual springs, solid stainless exhaust valves
7. Torquer cam/PSI springs, Ti exhaust valve
The Torquer cam will be an example of your typical aftermarket cam lobe profile.
If there is any vendor out there who wishes to have their combination tested we would be happy to include it in the mix for just the cost of running the additional combinations.
Input is encouraged.
We would like to run this test as soon as possible. The valvetrain test cell is currently down due to computer problems, but repairs are in progress that should get it back up and running within days. Because it was down there is a bit of a backup of programs that are waiting for testing so we will have to wait in line, but once it gets fixed that should go through smoothly. In other words, I can't guarantee exactly when, but it will get done soon.
Here is how I see the test plan:
1. Stock cam/springs, stock valves
2. Stock cam/springs, solid stainless exhaust valve
3. Stock cam/dual springs, solid stainless exhaust valve
4. Torquer cam/PSI springs, stock valves (already tested long ago, but we will baseline again)
5. Torquer cam/PSI springs, solid stainless exhaust valves
6. Torquer cam/dual springs, solid stainless exhaust valves
7. Torquer cam/PSI springs, Ti exhaust valve
The Torquer cam will be an example of your typical aftermarket cam lobe profile.
If there is any vendor out there who wishes to have their combination tested we would be happy to include it in the mix for just the cost of running the additional combinations.
Input is encouraged.
#4 has been done once already, has those results been posted on CF?
01-11-2013, 09:56 AM
#86
Melting Slicks
totally cool!! 
perfect timing for me as my mods have just started showing up....was going to contact katech about the torquer....my 07 with 37k has been great....i prefer beehive springs myself .... trying to decide what to do to heads/ what cam to install...i know this goes against the grain here but i also prefer the factory valves / guides...i truly believe when everything is as designed these are good for 100k...
my own past experience with aftermarket springs/retainers/guides and extreme cams is they will never be 100k type mods...so cant wait to see the results
perfect timing for me as my mods have just started showing up....was going to contact katech about the torquer....my 07 with 37k has been great....i prefer beehive springs myself .... trying to decide what to do to heads/ what cam to install...i know this goes against the grain here but i also prefer the factory valves / guides...i truly believe when everything is as designed these are good for 100k...
my own past experience with aftermarket springs/retainers/guides and extreme cams is they will never be 100k type mods...so cant wait to see the results
While I applaud Kateck's willingness to do some spinton testing this will do absolutely NOTHING to identifing exactly what EXECUTION problem is causing the premature failures. So while all of those people who have heavy exhaust valves will find out whether they need to lower their rev limit and/or what spring they NEED to run to control their heavier valves, they still wont have a clue as to whether the 'fix' they have invested in will have ANY impact over the long run.
So no matter how many times Ricky repeats himself about how this is "real research" and how others attempting to identify what the EXECUTION problem is, are just wasting time, he seems to have missed out on the fact that what Katech is about to research has nothing to do with what the root cause is of the failures. Of course this is understandable since one who has already spent the time/effort/money on what they believe will solve the 'root cause' problem have NO interest in knowing the answer to that question...in fact they can only sleep better at night NOT knowing what the answer is.
IMHO a true service to the community would be to determine what the root cause is...doing reasearch into determining what spring or valve to run so you can hopefully achieve the same valvetrain stability one has with a STOCK engine while using NON-stock parts, clearly only serves the interests of selling more non-stock parts. Of course since this IS the business Katech is in, their proposed testing is completely logical for them.
Cheers, Paul.
BTW, for the record I don't believe simply saying "the problem is the guides" answers anything since those same guides can and have proven themselves in many cars over the very long run. IF one were to say "the problem is the guides because SOMETIMES they have been installed or machined incorrectly" it would be a completely different statement, one which would require much more research to make. So personally I wont discourage anyone from attempting that sort of research and would NEVER claim such attempts are a disservice to the community.
Last edited by MTIRC6Z; 01-11-2013 at 10:09 AM.
01-11-2013, 10:04 AM
#87
Team Owner
Do you preclude the possibility that the SS valve and correct corresponding spring could actually be more stable at and even above 7000 RPM than the OEM ??
DH
01-11-2013, 10:07 AM
#88
4th Gear
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Your test plan:
Here is how I see the test plan:
1. Stock cam/springs, stock valves
2. Stock cam/springs, solid stainless exhaust valve
3. Stock cam/dual springs, solid stainless exhaust valve
4. Torquer cam/PSI springs, stock valves (already tested long ago, but we will baseline again)
5. Torquer cam/PSI springs, solid stainless exhaust valves
6. Torquer cam/dual springs, solid stainless exhaust valves
7. Torquer cam/PSI springs, Ti exhaust valve
======================================== =====
Hallo Jason,
This is good news
You advised me to go to WCC Richard
Richard Reyman
West Coast Cylinder Heads
18405 Hart St.
Reseda, CA 91335
www.proheads.com
(818) 705-5454
mailto:richard@proheads.com
I installed his advised Brodix heads in my C6 Z06 -2007 with:
Brodix LS7 CNC porter's casting
REV LS7 Exhaust Valve 1.625" 8mm 5.230" OAL w/.290 tip.
GM LS7 titanium intake valve
GM Lash cap for titanium valve
Patriot Extreme Spring Kit 1 290.00
CNC BR 265-99-71 CNC Porting 265-99-71 for all Brodix BR7 castings
Comp V8 Competition Valve Job V8 Cylinder Heads
Hone to size Hone Guides to size (V8 Heads)
Surface V8 & V6 Surface V8 and V6 Cylinder Heads Minimum .030"
Assemble Wash and finsh assemble
Regards Rinus
Here is how I see the test plan:
1. Stock cam/springs, stock valves
2. Stock cam/springs, solid stainless exhaust valve
3. Stock cam/dual springs, solid stainless exhaust valve
4. Torquer cam/PSI springs, stock valves (already tested long ago, but we will baseline again)
5. Torquer cam/PSI springs, solid stainless exhaust valves
6. Torquer cam/dual springs, solid stainless exhaust valves
7. Torquer cam/PSI springs, Ti exhaust valve
======================================== =====
Hallo Jason,
This is good news
You advised me to go to WCC Richard
Richard Reyman
West Coast Cylinder Heads
18405 Hart St.
Reseda, CA 91335
www.proheads.com
(818) 705-5454
mailto:richard@proheads.com
I installed his advised Brodix heads in my C6 Z06 -2007 with:
Brodix LS7 CNC porter's casting
REV LS7 Exhaust Valve 1.625" 8mm 5.230" OAL w/.290 tip.
GM LS7 titanium intake valve
GM Lash cap for titanium valve
Patriot Extreme Spring Kit 1 290.00
CNC BR 265-99-71 CNC Porting 265-99-71 for all Brodix BR7 castings
Comp V8 Competition Valve Job V8 Cylinder Heads
Hone to size Hone Guides to size (V8 Heads)
Surface V8 & V6 Surface V8 and V6 Cylinder Heads Minimum .030"
Assemble Wash and finsh assemble
Regards Rinus
01-11-2013, 10:14 AM
#89
Melting Slicks
Cheers, Paul.
01-11-2013, 10:14 AM
#90
Sub'd anyway.
01-11-2013, 10:35 AM
#92
Premium Supporting Vendor
Thread Starter
Actually since there are many Z06s running around with 100,000+ miles (and in at least one case 200,000+) it is obvious DESIGN is not an issue, thus to explain premature failures you must conclude that periodically there is an issue with improper EXECUTION of a proper design.
While I applaud Kateck's willingness to do some spinton testing this will do absolutely NOTHING to identifing exactly what EXECUTION problem is causing the premature failures. So while all of those people who have heavy exhaust valves will find out whether they need to lower their rev limit and/or what spring they NEED to run to control their heavier valves, they still wont have a clue as to whether the 'fix' they have invested in will have ANY impact over the long run.
So no matter how many times Ricky repeats himself about how this is "real research" and how others attempting to identify what the EXECUTION problem is, are just wasting time, he seems to have missed out on the fact that what Katech is about to research has nothing to do with what the root cause is of the failures. Of course this is understandable since one who has already spent the time/effort/money on what they believe will solve the 'root cause' problem have NO interest in knowing the answer to that question...in fact they can only sleep better at night NOT knowing what the answer is.
IMHO a true service to the community would be to determine what the root cause is...doing reasearch into determining what spring or valve to run so you can hopefully achieve the same valvetrain stability one has with a STOCK engine while using NON-stock parts, clearly only serves the interests of selling more non-stock parts. Of course since this IS the business Katech is in, their proposed testing is completely logical for them.
Cheers, Paul.
BTW, for the record I don't believe simply saying "the problem is the guides" answers anything since those same guides can and have proven themselves in many cars over the very long run. IF one were to say "the problem is the guides because SOMETIMES they have been installed or machined incorrectly" it would be a completely different statement, one which would require much more research to make. So personally I wont discourage anyone from attempting that sort of research and would NEVER claim such attempts are a disservice to the community.
While I applaud Kateck's willingness to do some spinton testing this will do absolutely NOTHING to identifing exactly what EXECUTION problem is causing the premature failures. So while all of those people who have heavy exhaust valves will find out whether they need to lower their rev limit and/or what spring they NEED to run to control their heavier valves, they still wont have a clue as to whether the 'fix' they have invested in will have ANY impact over the long run.
So no matter how many times Ricky repeats himself about how this is "real research" and how others attempting to identify what the EXECUTION problem is, are just wasting time, he seems to have missed out on the fact that what Katech is about to research has nothing to do with what the root cause is of the failures. Of course this is understandable since one who has already spent the time/effort/money on what they believe will solve the 'root cause' problem have NO interest in knowing the answer to that question...in fact they can only sleep better at night NOT knowing what the answer is.
IMHO a true service to the community would be to determine what the root cause is...doing reasearch into determining what spring or valve to run so you can hopefully achieve the same valvetrain stability one has with a STOCK engine while using NON-stock parts, clearly only serves the interests of selling more non-stock parts. Of course since this IS the business Katech is in, their proposed testing is completely logical for them.
Cheers, Paul.
BTW, for the record I don't believe simply saying "the problem is the guides" answers anything since those same guides can and have proven themselves in many cars over the very long run. IF one were to say "the problem is the guides because SOMETIMES they have been installed or machined incorrectly" it would be a completely different statement, one which would require much more research to make. So personally I wont discourage anyone from attempting that sort of research and would NEVER claim such attempts are a disservice to the community.
01-11-2013, 10:36 AM
#93
Team Owner
1. BT Platinum dual spring kit. For .660" Lift.
2. REV LS7 Exhaust Valve 1.615" 8mm 5.230" OAL w/.290 tip.
DH
01-11-2013, 10:44 AM
#94
Drifting
DH
They were also using the Manley Dual Spring Kit p/n 221436 which is what they put in my heads..... They are a .660 spring set also.
Mark
01-11-2013, 11:39 AM
#95
Yes. I would like to see a quality dual spring tested with an SS valve and a cam not on xer lobes. I would be willing to provide a cam.
01-11-2013, 12:27 PM
#97
Racer
Of course this is understandable since one who has already spent the time/effort/money on what they believe will solve the 'root cause' problem have NO interest in knowing the answer to that question...in fact they can only sleep better at night NOT knowing what the answer is.
Another great thread...I will stay tuned to see the results. And will interpret the results with a totally impartial mindset.
01-11-2013, 12:44 PM
#98
The Consigliere
Member Since: May 2006
Location: 2023 Z06 & 2010 ZR1
Posts: 22,259
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I'm in for the learning.
01-11-2013, 01:16 PM
#99
The problem is the guides because some of them were machined incorrectly. GM has stated this. Please lets not turn this thread into another debate on whether or not that is the problem. This thread is about valvetrain dynamics testing different valves, not a guide wear debate.
Well put Jason.
Go ahead and get started on the research and don't let any of this other junk impede that progress.
Best of luck and I'm looking forward to your results.
Rick.
01-11-2013, 01:47 PM
#100
Burning Brakes
The problem is the guides because some of them were machined incorrectly. GM has stated this. Please lets not turn this thread into another debate on whether or not that is the problem. This thread is about valvetrain dynamics testing different valves, not a guide wear debate.
