[Z06] Drop Valve
08-06-2012, 09:12 AM
#61
Race Director
Seems like the info you guys always request is specifically for a "random" cause to blame instead of shoddy build quality which it clearly is.
I will also toss my offer to pay for shipping of the head to chadyellow if the OP wants to have the head to be inspected.
We're interested in a fix for an admitted problem. That's all. It will benefit the community as a whole.
I will also toss my offer to pay for shipping of the head to chadyellow if the OP wants to have the head to be inspected.
We're interested in a fix for an admitted problem. That's all. It will benefit the community as a whole.
I am not looking to blame it on a random cause, if you read my post I said "maybe" I am wrong and it is guide wear...but we don't know for sure until the heads are looked at and examined more. You are correct, the information will benefit the community as a whole.. but only IF it's complete and accurate.
with your whole post, but especially this part. As soon as people hear "valve drop" now the flavor of the day is everyone jumping at screaming at guide wear, because it is now surfacing more.While it's probably obvious in this case a spring didn't break ( I was just using that as an example) it could be a host of other things as you pointed out.
If it comes back there is guide wear, so be it, add it to the list with the rest... all a lot of us are saying is lets get a little more information before we start assuming we know what happened.
To tell you the truth, I'd rather his heads be looked over by someone who is non-biased to what is going on here..a reputable shop of professionals that have no dog in the fight.
Last edited by FrankTank; 08-06-2012 at 09:16 AM.
08-06-2012, 09:19 AM
#62
Race Director
well it dropped an exhaust valve...if it was a broken valve spring i'm sure he would have seen it..he had to take the heads off to get those pictures of the piston...the valve spring would have been seen by removing the valve covers. there are head bolts under those valve covers..i also got 505-z06 head here a few days ago..24k track miles no guide wear...never the less it dropped an exhaust valve..
08-06-2012, 09:52 AM
#64
Le Mans Master
Quick I got the head bare just the castings..their at the shop waiting on specs and will post next week..If there was guide wear it was very little. if it was valve float causing the problem with dropped valves why is it just the exhaust valve and not intake..intake valve weighs more about 6grams..yet there isn't much if any intake guide wear that I have seen. I will know more soon I'm cutting 505-z06 head in half after the guides are speced..that way I can start taking measurements of all water jakets Ect...If I can get any used valves I now got the tools to cut it and measure stem thickness...these cars are dropping valves...I think it's the exhaust valve...but I may be wrong...but I'll figure it out..it can only be 1 of three things..1 exhaust valves getting to hot wearing out the guides.2 bad guides.3 design flaw in all heads from 06-13..anyone want to ship me your toasted head or heads i will spec the quides free to enyone that sends them to me.but would like to keep the head to figure this out i'm not rich if I was I would have already figured it out I will also post up the guide spec sheet so everyone can see. I will do videos if asked of any heads I get from you guys I'm tring to help you all. just don't always believe what your told start thinking for yourselfs....all of you guys should ask the real ppl that already know the problem..and that would be gm..and a few very well know vendors that wont even post about it...G I wonder why? on a side..get the stock springs out of the cars if your not covered by warr
Unfortunately, since we don't know what the root cause is definitively, the list of possible causes is much longer.
Speculating why some vendors won't post about his isn't helping, and means nothing.
08-06-2012, 10:07 AM
#65
Le Mans Master
No, just wanting more information before coming to a conclusion about what or why it happened that's all, nothing more nothing less. Like I said , I find it disturbing that people are being slammed for asking questions and wanting more information.
I am not looking to blame it on a random cause, if you read my post I said "maybe" I am wrong and it is guide wear...but we don't know for sure until the heads are looked at and examined more. You are correct, the information will benefit the community as a whole.. but only IF it's complete and accurate.
with your whole post, but especially this part. As soon as people hear "valve drop" now the flavor of the day is everyone jumping at screaming at guide wear, because it is now surfacing more.
While it's probably obvious in this case a spring didn't break ( I was just using that as an example) it could be a host of other things as you pointed out.
If it comes back there is guide wear, so be it, add it to the list with the rest... all a lot of us are saying is lets get a little more information before we start assuming we know what happened.
To tell you the truth, I'd rather his heads be looked over by someone who is non-biased to what is going on here..a reputable shop of professionals that have no dog in the fight.
I am not looking to blame it on a random cause, if you read my post I said "maybe" I am wrong and it is guide wear...but we don't know for sure until the heads are looked at and examined more. You are correct, the information will benefit the community as a whole.. but only IF it's complete and accurate.
with your whole post, but especially this part. As soon as people hear "valve drop" now the flavor of the day is everyone jumping at screaming at guide wear, because it is now surfacing more.While it's probably obvious in this case a spring didn't break ( I was just using that as an example) it could be a host of other things as you pointed out.
If it comes back there is guide wear, so be it, add it to the list with the rest... all a lot of us are saying is lets get a little more information before we start assuming we know what happened.
To tell you the truth, I'd rather his heads be looked over by someone who is non-biased to what is going on here..a reputable shop of professionals that have no dog in the fight.
Why hasn't the reputable shop that starts with a K, hasn't posted anything in this obvious flaw?
Are you that blind? , do you want to help the owners, you obviously have zero knowledge of motors, and dont want to listen to people who do.
I'll break this down very simple
1.Complete cnc of the bare head to exact spec
2. A real set of springs
3, a real set of 1 piece push rods, not the 3 piece junk that can be found in a 20 year old mustang
4. Shaft mounted T&D or jessel rockers(T&D work just as good and are $300 cheaper)
4. ARP rocker studs
5. Stock retainers are fine
Won't even need bronze guides if you follow the above
Do this, head problem solved, period.
This has been done on a half dozen blown LS7's that I have personally seen.
:beatdeadh orse::beat deadhorse:
08-06-2012, 10:25 AM
#66
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Member Since: Sep 2011
Location: Birmingham Michigan
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All I can say is that when I get my next z0, the valves, guides and springs are being replaced right away. I can guarantee that it won't drop a valve then. Luckily, both Livernois and Katech (even though Katech say stock 2 piece valves are fine) are both about 15 miles down the road. Done and done!
Last edited by palindrome1H; 08-06-2012 at 10:37 AM.
08-06-2012, 10:43 AM
#67
Le Mans Master
Exhaust valve to piston clearance is far more critical because the piston is always "chasing" the exhaust valve as it closes. As such, it might be possible the piston is making some contact with the exhaust valve if it's floating.
Unfortunately, since we don't know what the root cause is definitively, the list of possible causes is much longer.
Speculating why some vendors won't post about his isn't helping, and means nothing.
Unfortunately, since we don't know what the root cause is definitively, the list of possible causes is much longer.
Speculating why some vendors won't post about his isn't helping, and means nothing.
08-06-2012, 10:50 AM
#68
Le Mans Master
You are getting unbiased facts from professionals in reputable shops that have no dog in this fight!!!!!, just trying to help, for gods sake!!!
Why hasn't the reputable shop that starts with a K, hasn't posted anything in this obvious flaw?Are you that blind? , do you want to help the owners, you obviously have zero knowledge of motors, and dont want to listen to people who do.
I'll break this down very simple
1.Complete cnc of the bare head to exact spec
2. A real set of springs
3, a real set of 1 piece push rods, not the 3 piece junk that can be found in a 20 year old mustang
4. Shaft mounted T&D or jessel rockers(T&D work just as good and are $300 cheaper)
4. ARP rocker studs
5. Stock retainers are fine
Won't even need bronze guides if you follow the above
Do this, head problem solved, period.
This has been done on a half dozen blown LS7's that I have personally seen.
:beatdeadh orse::beat deadhorse:
Why hasn't the reputable shop that starts with a K, hasn't posted anything in this obvious flaw?Are you that blind? , do you want to help the owners, you obviously have zero knowledge of motors, and dont want to listen to people who do.
I'll break this down very simple
1.Complete cnc of the bare head to exact spec
2. A real set of springs
3, a real set of 1 piece push rods, not the 3 piece junk that can be found in a 20 year old mustang
4. Shaft mounted T&D or jessel rockers(T&D work just as good and are $300 cheaper)
4. ARP rocker studs
5. Stock retainers are fine
Won't even need bronze guides if you follow the above
Do this, head problem solved, period.
This has been done on a half dozen blown LS7's that I have personally seen.
:beatdeadh orse::beat deadhorse:
08-06-2012, 11:47 AM
#69
Advanced
Thread Starter
Thanks Evan. I called Customer Service this morning and my warranty expired back in August 2011. I just ordered the piston and rod right now. I have a lot of more parts to order.
08-06-2012, 12:33 PM
#70
Instructor
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When paying this much money for a car, you expect it to be decent quality.
I've always went with GM cars (Vettes\FBodies) as my main car because say what you will about the interiors, their engines\trannies have always been rock solid for the most part.
Evan I hope GM does the right thing here and:
1. Is investigating this because there's clearly an issue
2. Doesn't sweep it under the rug because it's not going away and seems to affect all years
3. Steps up and helps this guy out by replacing his engine or only charging him labor...
08-06-2012, 12:46 PM
#71
Burning Brakes
Member Since: Oct 2007
Location: Chicago area Illinois
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Seems like the info you guys always request is specifically for a "random" cause to blame instead of shoddy build quality which it clearly is.
I will also toss my offer to pay for shipping of the head to chadyellow if the OP wants to have the head to be inspected.
We're interested in a fix for an admitted problem. That's all. It will benefit the community as a whole.
I will also toss my offer to pay for shipping of the head to chadyellow if the OP wants to have the head to be inspected.
We're interested in a fix for an admitted problem. That's all. It will benefit the community as a whole.
Thank you for your generous offer.....it is appreciated by me and hopefully many others. Maybe the forum members who have the knowledge can get the root cause figured out since GM can't, won't, or already has figured the cause, and figures it's cheaper to fix the failures still under warranty than to step up and do the right thing for all owners with this issue.
08-06-2012, 01:15 PM
#72
Racer
Member Since: Sep 2011
Location: Birmingham Michigan
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Thank you for your generous offer.....it is appreciated by me and hopefully many others. Maybe the forum members who have the knowledge can get the root cause figured out since GM can't, won't, or already has figured the cause, and figures it's cheaper to fix the failures still under warranty than to step up and do the right thing for all owners with this issue.
08-06-2012, 02:23 PM
#73
Race Director
You are getting unbiased facts from professionals in reputable shops that have no dog in this fight!!!!!, just trying to help, for gods sake!!!
Why hasn't the reputable shop that starts with a K, hasn't posted anything in this obvious flaw?
Are you that blind? , do you want to help the owners, you obviously have zero knowledge of motors, and dont want to listen to people who do.
I'll break this down very simple
1.Complete cnc of the bare head to exact spec
2. A real set of springs
3, a real set of 1 piece push rods, not the 3 piece junk that can be found in a 20 year old mustang
4. Shaft mounted T&D or jessel rockers(T&D work just as good and are $300 cheaper)
4. ARP rocker studs
5. Stock retainers are fine
Won't even need bronze guides if you follow the above
Do this, head problem solved, period.
This has been done on a half dozen blown LS7's that I have personally seen.
:beatdeadh orse::beat deadhorse:
Why hasn't the reputable shop that starts with a K, hasn't posted anything in this obvious flaw?
Are you that blind? , do you want to help the owners, you obviously have zero knowledge of motors, and dont want to listen to people who do.
I'll break this down very simple
1.Complete cnc of the bare head to exact spec
2. A real set of springs
3, a real set of 1 piece push rods, not the 3 piece junk that can be found in a 20 year old mustang
4. Shaft mounted T&D or jessel rockers(T&D work just as good and are $300 cheaper)
4. ARP rocker studs
5. Stock retainers are fine
Won't even need bronze guides if you follow the above
Do this, head problem solved, period.
This has been done on a half dozen blown LS7's that I have personally seen.
:beatdeadh orse::beat deadhorse:I am not debating a fix with you...if you were not so blind , you would have read where I stated I was not disagreeing on that point.
I am not going to stoop to the personal attacks, and trying to judge people off a few posts. You have 0 idea of my knowledge of motors.
Nice try.I find it funny how those who think there is a widespread problem can say they are being "blunt"... yet when those of us who are still wanting more information and answers , and are not yet convinced speak up, it's an attack on whomevers blown motor it is
Last edited by FrankTank; 08-06-2012 at 02:26 PM.
08-06-2012, 03:31 PM
#74
Le Mans Master
I think you are right on. GM knows it is an issue. Could you imagine a recall on all LS7 motors? It would cripple service departments. Just fixem as they break. By not revising the LS7 for 2013 they don't admit to it being a fault or weak point. Plus no one has been killed from their LS7 giving out and hopefully never.
08-06-2012, 04:01 PM
#75
Melting Slicks
08-06-2012, 04:45 PM
#76
Le Mans Master
It is not GMs choice on doing a recall. This is under the jusidiction of the NHTSA.
It is not possible to build 28,000 motors for 8 years - that need a recall and doesn't get one.
08-06-2012, 04:49 PM
#77
Your the blind one, other shops have posted up about it, LG and Livernois as well, in addition to Richierich Z06. And Katech has in fact posted an entire thread about it...missed that one didn't you.. yea ok I am blind.. GMAFB
I am not debating a fix with you...if you were not so blind , you would have read where I stated I was not disagreeing on that point.
I am not going to stoop to the personal attacks, and trying to judge people off a few posts. You have 0 idea of my knowledge of motors. Nice try.
I find it funny how those who think there is a widespread problem can say they are being "blunt"... yet when those of us who are still wanting more information and answers , and are not yet convinced speak up, it's an attack on whomevers blown motor it is
I am not debating a fix with you...if you were not so blind , you would have read where I stated I was not disagreeing on that point.
I am not going to stoop to the personal attacks, and trying to judge people off a few posts. You have 0 idea of my knowledge of motors.
Nice try.I find it funny how those who think there is a widespread problem can say they are being "blunt"... yet when those of us who are still wanting more information and answers , and are not yet convinced speak up, it's an attack on whomevers blown motor it is
I felt the same way when I made the thread for just build dates i got attacked by cavemen.
08-06-2012, 05:06 PM
#78
Instructor
Member Since: Jul 2012
Location: Lakeland FL
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..richard will tell you straight up get those exhaust valves out of the car..yes katech says use the stock valves....well stock valves failing one after another over and over again..hmm I'm using ss valves in my heads ...in fact the z06 is the only car i've ever owned with hollow exhaust valves and i've had many 9 sec cars...never dropped a valve not once..
08-06-2012, 06:31 PM
#79
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
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You are getting unbiased facts from professionals in reputable shops that have no dog in this fight!!!!!, just trying to help, for gods sake!!!
Why hasn't the reputable shop that starts with a K, hasn't posted anything in this obvious flaw?
Are you that blind? , do you want to help the owners, you obviously have zero knowledge of motors, and dont want to listen to people who do.
I'll break this down very simple
1.Complete cnc of the bare head to exact spec
2. A real set of springs
3, a real set of 1 piece push rods, not the 3 piece junk that can be found in a 20 year old mustang
4. Shaft mounted T&D or jessel rockers(T&D work just as good and are $300 cheaper)
4. ARP rocker studs
5. Stock retainers are fine
Won't even need bronze guides if you follow the above
Do this, head problem solved, period.
This has been done on a half dozen blown LS7's that I have personally seen.
:beatdeadh orse::beat deadhorse:
Why hasn't the reputable shop that starts with a K, hasn't posted anything in this obvious flaw?
Are you that blind? , do you want to help the owners, you obviously have zero knowledge of motors, and dont want to listen to people who do.
I'll break this down very simple
1.Complete cnc of the bare head to exact spec
2. A real set of springs
3, a real set of 1 piece push rods, not the 3 piece junk that can be found in a 20 year old mustang
4. Shaft mounted T&D or jessel rockers(T&D work just as good and are $300 cheaper)
4. ARP rocker studs
5. Stock retainers are fine
Won't even need bronze guides if you follow the above
Do this, head problem solved, period.
This has been done on a half dozen blown LS7's that I have personally seen.
:beatdeadh orse::beat deadhorse:The problem is nobody knows whether that will solve the problem. Or will it drop the head of an exhuast valve like other engines have done after 40 track days and 4K miles of Wide Open Throttle driving and 20K street miles.
Of the half dozen you have seen how many have been on the road long enough for the problem to show its ugly head again?
Bill
Last edited by Bill Dearborn; 08-06-2012 at 06:33 PM.
08-06-2012, 06:37 PM
#80
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
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It just sucks that you, and others that have experienced failures, have to deal with this...
When paying this much money for a car, you expect it to be decent quality.
I've always went with GM cars (Vettes\FBodies) as my main car because say what you will about the interiors, their engines\trannies have always been rock solid for the most part.
Evan I hope GM does the right thing here and:
1. Is investigating this because there's clearly an issue
2. Doesn't sweep it under the rug because it's not going away and seems to affect all years
3. Steps up and helps this guy out by replacing his engine or only charging him labor...
When paying this much money for a car, you expect it to be decent quality.
I've always went with GM cars (Vettes\FBodies) as my main car because say what you will about the interiors, their engines\trannies have always been rock solid for the most part.
Evan I hope GM does the right thing here and:
1. Is investigating this because there's clearly an issue
2. Doesn't sweep it under the rug because it's not going away and seems to affect all years
3. Steps up and helps this guy out by replacing his engine or only charging him labor...
Bill