[Z06] Exhaust Valve Failures
10-25-2012, 12:20 AM
#1
Burning Brakes
Thread Starter
Exhaust Valve Failures
Hey guys,
I'm posting this on behalf of valet who is deployed right now. My name is Anne and I'm a materials engineer. He wanted me to help rule out exhaust valves as the point of failure. He had been following this issue until a few weeks ago, so if this is a moot point, my apologies. The overall goal here is to find inherent issues \ incompatibilities with the exhaust valves.
Here's what I need:
* one new (post May '08?) valve
* one broken valve
* one old design valve
* a rough schematic of what the valve does, normal operating temperatures, maximum temperature, pressures and speeds
Here's what we will try to answer using typical failure analysis methods (SEM, micrography, etc.)
* what the beginning failure point was (weld, metal, etc.)
* why it failed
* possible mitigation techniques
PM me for the address to send it to and I will post results as they come up. Valet passes: "Thanks for your help on this issue, guys."
END
I'm posting this on behalf of valet who is deployed right now. My name is Anne and I'm a materials engineer. He wanted me to help rule out exhaust valves as the point of failure. He had been following this issue until a few weeks ago, so if this is a moot point, my apologies. The overall goal here is to find inherent issues \ incompatibilities with the exhaust valves.
Here's what I need:
* one new (post May '08?) valve
* one broken valve
* one old design valve
* a rough schematic of what the valve does, normal operating temperatures, maximum temperature, pressures and speeds
Here's what we will try to answer using typical failure analysis methods (SEM, micrography, etc.)
* what the beginning failure point was (weld, metal, etc.)
* why it failed
* possible mitigation techniques
PM me for the address to send it to and I will post results as they come up. Valet passes: "Thanks for your help on this issue, guys."
END
10-25-2012, 12:29 AM
#2
Hey guys,
I'm posting this on behalf of valet who is deployed right now. My name is Anne and I'm a materials engineer. He wanted me to help rule out exhaust valves as the point of failure. He had been following this issue until a few weeks ago, so if this is a moot point, my apologies. The overall goal here is to find inherent issues \ incompatibilities with the exhaust valves.
Here's what I need:
* one new (post May '08?) valve
* one broken valve
* one old design valve
* a rough schematic of what the valve does, normal operating temperatures, maximum temperature, pressures and speeds
Here's what we will try to answer using typical failure analysis methods (SEM, micrography, etc.)
* what the beginning failure point was (weld, metal, etc.)
* why it failed
* possible mitigation techniques
PM me for the address to send it to and I will post results as they come up. Valet passes: "Thanks for your help on this issue, guys."
END
I'm posting this on behalf of valet who is deployed right now. My name is Anne and I'm a materials engineer. He wanted me to help rule out exhaust valves as the point of failure. He had been following this issue until a few weeks ago, so if this is a moot point, my apologies. The overall goal here is to find inherent issues \ incompatibilities with the exhaust valves.
Here's what I need:
* one new (post May '08?) valve
* one broken valve
* one old design valve
* a rough schematic of what the valve does, normal operating temperatures, maximum temperature, pressures and speeds
Here's what we will try to answer using typical failure analysis methods (SEM, micrography, etc.)
* what the beginning failure point was (weld, metal, etc.)
* why it failed
* possible mitigation techniques
PM me for the address to send it to and I will post results as they come up. Valet passes: "Thanks for your help on this issue, guys."
END
I have a box of 8 OEM exhaust valves from my 2006 that nobody over in the for sale section seems to want to purchase from me.
You are welcome to them.
10-25-2012, 06:08 PM
#3
Burning Brakes
10-25-2012, 06:52 PM
#4
Racer
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The problem with doin SEM micrography on a broken valve is the fact that the crack propagation site is often damaged during the mayhem after the valve separation. I had a set of valves sent to me with one broken with hopes to do the same...but i was unable to find the site of the crack because of how mashed both the stem and the head were. Keep in mind the failed valve showed NO signs of a worn guide.
10-25-2012, 06:58 PM
#5
Instructor
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The problem with doin SEM micrography on a broken valve is the fact that the crack propagation site is often damaged during the mayhem after the valve separation. I had a set of valves sent to me with one broken with hopes to do the same...but i was unable to find the site of the crack because of how mashed both the stem and the head were. Keep in mind the failed valve showed NO signs of a worn guide.
if your talking about z06-505 the guides were all in spec...i still have the head if you want i can ship it to you...
10-25-2012, 07:16 PM
#7
I was hoping maybe I could sell them to a forum member with a set of bare heads, looking to do them with stock exhaust valves and either bronze guides or powdered steel guides, like the way the big shops do them.
But I guess nobody is interested.
I haven't gotten a single bite on them.
10-25-2012, 07:22 PM
#8
Instructor
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I was hoping maybe I could sell them to a forum member with a set of bare heads, looking to do them with stock exhaust valves and either bronze guides or powdered steel guides, like the way the big shops do them.
But I guess nobody is interested.
I haven't gotten a single bite on them.
But I guess nobody is interested.
I haven't gotten a single bite on them.
....how are you liking the new setup ricky?
Last edited by chadyellowz06; 10-25-2012 at 07:29 PM.
10-25-2012, 08:11 PM
#9
Team Owner
"* a rough schematic of what the valve does, normal operating temperatures, maximum temperature, pressures and speeds"
Good luck with that. At best you can get some ballpark estimates.
Good luck with that. At best you can get some ballpark estimates.
10-25-2012, 08:32 PM
#10
Burning Brakes
I was hoping maybe I could sell them to a forum member with a set of bare heads, looking to do them with stock exhaust valves and either bronze guides or powdered steel guides, like the way the big shops do them.
But I guess nobody is interested.
I haven't gotten a single bite on them.
But I guess nobody is interested.
I haven't gotten a single bite on them.
10-25-2012, 11:07 PM
#11
Le Mans Master
Member Since: Jan 2009
Location: Pottsboro; Sometimes Dallas Texas
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St. Jude Donor '12
There is a academy of engineers, (cannot remember the name) and the GM engineers released that data i believe back in 2006. I also saw it posted on web someplace a few years back....one of the info sites.
10-25-2012, 11:09 PM
#12
Melting Slicks
11-05-2012, 05:39 AM
#13
Burning Brakes
Thread Starter
Gents,
I'm taking advantage of a rare moment for internet connectivity. Thanks to Quick for his submission. I still need a broken valve and a post May 2008 valve. chadyellowz06, I'm singling you out.
I'm taking advantage of a rare moment for internet connectivity. Thanks to Quick for his submission. I still need a broken valve and a post May 2008 valve. chadyellowz06, I'm singling you out.
11-05-2012, 08:34 AM
#14
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11-15-2012, 11:56 PM
#15
Burning Brakes
Thread Starter
Moderator: Can I change the thread title to "New and broken exhaust valve needed for research"? My friend posted this for me and didn't realize how generic this title would be, unfortunately.
Chad, I wouldn't ask you to spend the money to send the entire head, since all these engineers are going to look at is the valve, but a valve guide could be useful as they look at metallic incompatibilities. Any luck getting a hold of that broken 2010 exhaust valve? That's the one I really want analyzed.
To everyone else, I need one of the following donated to science: A post 2008 e valve and any broken exhaust valve. I know members like vertc6 have research going on as well. Think of this as covering all the bases, not merely being redundant.
Chad, I wouldn't ask you to spend the money to send the entire head, since all these engineers are going to look at is the valve, but a valve guide could be useful as they look at metallic incompatibilities. Any luck getting a hold of that broken 2010 exhaust valve? That's the one I really want analyzed.
To everyone else, I need one of the following donated to science: A post 2008 e valve and any broken exhaust valve. I know members like vertc6 have research going on as well. Think of this as covering all the bases, not merely being redundant.
11-17-2012, 09:28 PM
#17
Burning Brakes
Thread Starter
Thanks everyone. So far I have an old valve and a broken valve coming at me. Just need a newer one to compare it. Hoefi, good call including the valve guide to look for material incompatibilities.
11-17-2012, 09:39 PM
#18
Local Chevy dealer would probably sell one for $40 if they had one in stock (probably not too likely.... I tried to buy one today along with some other stuff I already had ordered but my GM vendor didn't have any in stock).
GM Part Number: 12618110
Last edited by Mark2009; 11-17-2012 at 09:44 PM.
11-18-2012, 11:36 AM
#20
Melting Slicks
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Are you doing 3rd party testing to avoid the GOVERNMENT(motors) cover up? they seem to be pros at it anymore .. well maybe not pros but can be blaten about it and get a free pass.
Anyways, good luck. Shame these motors are failing with such low mileage too. I love my z06, but GM should really be stepping up to the plate and not force owner to spend their own cash to find answeres. GM should be embarrased over this.
Anyways, good luck. Shame these motors are failing with such low mileage too. I love my z06, but GM should really be stepping up to the plate and not force owner to spend their own cash to find answeres. GM should be embarrased over this.