How Long Have People Been Running Solid Stainless Exhaust Valves in the LS7?
 

No. A mouse over is not going to get you your answer.

You know we hear a lot about how it is too early to tell if the use of solid stemmed Stainless exhaust valves is a "fix" for the exhaust valve failures reported in here.

I did a little research.

But before I share what I found in here, I want those who think that they are going to be upset, to exit this thread now.

Nobody put a gun to your head and made you click on this thread.

So if you think you're going to be sick, when you read what I found, well then now is your chance to leave. I won't be offended.

Thank you.

One more chance to leave, if this is going to be hard for you.

Don't read any further if it is going to be a problem.

Remember, nobody forced you to come in here if you think this news is going to get your blood pressure up.

Leave now if think it's going to ruffle your feathers.

I'm serious. Go ahead and hat up now, and start reading the other threads in here if you think this is going to get your underwear in a knot.

Last warning. Don't read the next post.

If you don't like entertaining the prospect that solid stainless steel exhaust valves are a fix for this mess that we are seeing, and are dead set against them, and like to holler about how it's "too early to tell if using them as a fix is effective", and valve float and other such talk, well then I'm telling you up front, and I wouldn't steer you wrong, for you, reading any further, is going to be worse than getting an enema. I strongly urge you, leave now if it's going to be a problem for you hear this news.

:lurk:

If you're still reading, then I have good news for some and bad news for others.

If you are still reading, well then you are probably open minded, logical, can think analytically, and can be reasoned with.

On the other hand, worst case scenario, the possibility also exist that some here who are still reading, are at the other end of the spectrum and have a hard time taking advice, have a reading comprehension problem, or simply cannot stay out of these sorts of threads when they come up, no matter what.

The cliff notes here; stainless steel exhaust valves have been used in members LS7 heads for going into 5 years now, and there are no reports of stainless steel valve failures among our members.

At any rate, the earliest indication of any vendor offering SS valves in heads for an LS7 is in the posting by Jason 98 TA of Texas Speed in his announcement of their announcement of their new PRC LS7 cnc cylinder head.

This was on October 5, 2007, or 62 months ago.

http://forums.corvetteforum.com/c6-z...available.html

20 months later, and better than 3 years ago, forum vendor tjwong, mentioned that he had been using "Ferrea SuperAlloy exhaust valves with excellent reliability"
http://forums.corvetteforum.com/c6-z...post1571240063 with good success

And then there is dfinke23 in September of 2008 http://forums.corvetteforum.com/c6-z...post1566945169

Since this time, going back to October 5, 2007, I find no reports of head breakage of solid stemmed stainless valves on this forum.

If anyone else has, then feel free to post up a link.

I believe that this goes to show, that the practice of using these valves in the LS7, as an alternative to the hollow stemmed sodium valves, has been around for a good portion of the LS7's tenure, and during that time, there are few, if ANY reports of the head snapping off of one of them.


When the original warranty on the C6 Z06 was 3yrs or 36K miles, whichever came first, I think that a record going back better than 5 years, and with a scarcity of reports of failure using these valves, is as good of "proof" as any, that many in here are on the right track, when the decision is made to change out the stock hollow stem exhaust valves for solid stainless ones.

A rash of failure reports, would of course indicate otherwise. However such has not been observed in here.

This is especially significant, when it is taken into account the number of stock hollow stemmed valve catastrophes which have taken place over the same time frame.

Quick:
What you say makes sense...to a point. However, I think you would agree that the absence of any bad news is not the same as the presence of good news. That is, first hand reports of 25,000 or 50,000 or 75,000 trouble free miles, including extended track sessions using SS valves would present a stronger case than does the absence of any reports of failures.

:lurk:

:iagree: Plus the number of stock engines vs engines with modified heads with SS Ex valves/Bronze guides is also a factor in the pool of data points available to support any substantial conclusions.

In 5 years and 2 months, the way we report mishaps in here, at least one person in here would have spoken up.

Does anyone know if anyone has been using SS exh valves/Bronze guides in LS7 heads for that long?

Okay, so the shocking revelation is that people have used non-OEM valves before? Oh. Well, any data is good data - I'm just not seeing the big deal or how this is a slam dunk?

How many miles on these cars again?

How many units are we using to show that this is "a "fix" for the exhaust valve failures?" three? maybe a dozen? Fifty?

And how many miles would a similar number of random factory-fresh Z06 go before failure?

There are always outliers (like a 2012 with 400 miles on it with out of spec guides - is that even the same problem?), but a handful of cars with a few successful years of driving doesn't mean much - when tens of thousands of OEM cars are performing to the same levels on average.

I think we might be jumping the gun here a bit on the significance of your links in comparison to your extrapolations. Doesn't mean solid valves still aren't a better choice for a lot of people here, just that I don't see how this is that big of a deal - notably since there is a conspicuous absence of follow up data involving mileage, lack of guide wear, etc?

Looks like it in that Texas Speed was offering up this configuration that long ago. But we know that there is at least one person in here who took the plunge better than 4 years ago.

http://forums.corvetteforum.com/c6-z...post1568228485

Apparently when they first came out, at Texas Speed, they were backordered.

http://forums.corvetteforum.com/c6-z...o-results.html
http://forums.corvetteforum.com/c6-z...post1563151856

I said earlier, that some people are going to do well with these findings, and some aren't. Some of us are going to take these findings hard.

I do believe though that the best approach here, in dealing with this matter for those taken aback by it, is to look at this in a "glass half full" manner as was suggested before by someone above.

There is not an actual "absence" of solid stainless steel failures resulting in windowed blocks on this forum. There is simply a lack of "presence" of those reports in here. :D

Nobody said anything about "slam dunks". Just that the way that the ball is bouncing, indicates that there are no reports of valve head breakage in here after all of these years.

The bottom line, is in how many descriptions of valve head breakage of solid stainless valves do we have in here, vs reports of valve head breakage in stock exhaust valves over the same period of time.

Quick, I'm quite sure that LGM Motorsports reported on this forum that they knew of two w/SS dropped valves, one on a dyno run. Maybe it was a stock valve though?

:rofl:

You have been at this for a long time too haven't you?

http://forums.corvetteforum.com/c6-z...post1571001370


LGM reported one failure of a SS valve in a race car from Alabama.

Could have been a broken valve spring for all we know.

I have yet to see an example of any member in here, losing the head off of a solid stemmed stainless exhaust valve into a combustion chamber, and windowing an engine block.

And I have gone through better than 5 years of posts.

So I think that we have either reached, or are reaching, a point to where we can no longer say, that the use of solid stemmed stainless steel valves as a viable fix, or preventive step, for the broken valve issue in the LS7, is an "unproven" method of dealing with the matter in terms of effectiveness.

This practice started better than 5 years ago, and is more common now than perhaps it has ever been, and there are no reports of failure which I could find in here.

If anyone else can point to one, well then please do post up the link.

.

No broken intake? Perhaps if GM OEM spec was SS for the exhaust and not sodium you would.
What I'm saying is, if the guides & seats are machined wrong sooner or later any valve would likely go.
Maybe if the exhaust came from the factory SS we would be reading about the Ti intake valves going first.
Its always WAY easier to blame the end result than to find the true RC.

Simple fact is, the folks that do KNOW, that work with these head daily are not sharing that knowledge. At least not on the forums right

:cry:cry. J/k as you were gentlemen :D

I don't think anyone here has collected more data than '06 QuickSilver, to date, even after 1500+ posts on the geometry, I'm going SS on the exhaust in my new heads. Regardless of what and how many reasons, bottom line, the stock hollow sodium ones are breaking. SS it is.

OK, we have one verified set of heads with SS exh valves (nothing on Bronze guides, although assumed) in a car for 4-5 years (does he still have this car with these heads?). What we need is a poll to see how many here have had this done, how long ago, total miles/track time to see what kind of sample size and data is available on this forum if one wants to come to some kind of reasonable conclusion IMHO. Otherwise, everything else is conjecture.

While he put that post up here a little more than 4 years ago, Bowtiguy finally had a problem.

But it wasn't a dropped or broken valve. And it does not appear to be the same WCCH setup he speaks of back in December of 2008, and possibly could be a different car.

Well, what do you know? He was using Titanium exhaust valves. :D

http://forums.corvetteforum.com/c6-z...post1577821539

http://forums.corvetteforum.com/c6-t...r-failure.html

Sounds like he had either his cam or a lifter go bad, but this appears to have been a different setup than his original setup in that he mentions Lingenfelter heads in the above threads. May even have been a different car.

But I find no posts in here saying where he has lost a motor, and his last activity in here was 11/14/12.

So I'm still waiting to find an example of someone in here having had the head snap off of a solid stainless valve and windowing an engine block.

Hahahahahaha.

Now who will be the first offended to reply :D

:cheers:
DH

Don't mess with Quick when it comes to data mining the forums. :thumbs:

Yeah, I can see that - but you're saying:

andbut there's no data here outside of a few vendors' posts on aftermarket head and rebuild options?

We don't know how many people are running solid SS valves, we don't know how many miles are on these converted cars, and we don't know how many failures (if any) there might be - only that none of that info has been reported here on the forum.

So again, I think if you want to literally say "hey, we can use solid SS valves in the LS7 without problems," then I agree. But your collective statements (and why you converted your car to solid valves) implies that you feel solid valves are a FIX for the LS7s - and nothing in this thread supports or disproves that.

Any typical hollow-stemmed factory LS7 will be expected to live longer than any converted car that I've seen posted so far in terms of mileage and driving style, so then I ask: if we have virtually no converted car that has yet exceeded the benchmarks of a typical production Z06, why are we posting yet another thread talking about how great the solid SS valves are for "a fix?"

Just seems like more propaganda and fodder for arguments to me... but I'll say again: I think solid valves are a good option for many people, I just don't see how your thread justifies any of this - other than pointing out that vendors have been selling aftermarket parts for the Z06 since 2007?

The purpose of the thread, is to illustrate that the use of solid stainless valves as a means of addressing the valve issue in the LS 7, is a method which has been around for a long TIME.

During that time period, no reports of valve failure are documented.

Some readers of this forum, after listening to yourself and others with your beliefs, would be led to think that the use of SS valves, is a practice which has not been around for any length if time.

The thread demonstrates that it has.

People who do this procedure, typically don't do it so that they can get 150k miles on cruise control.

They often do it to make the car more robust for occasional or even frequen track duty, in addition to street driving.

Thus one parameter to look at, in terms of success or failure, is in how many track seasons we have seen this fix, since it has been employed.

Knowing that some stock Z06s have not made it past even one track season, due to "missed shifts", it is encouraging to see that changing valves has eliminated the propensity for these missed shifts occurring.

Really though, the years, and full or partial track seasons, or even occasional forays, over these years, in cars with this upgrade, and the lack of failure reports, says a lot.

Since it seems that the thread causes you such consternation, and you don't grasp it's purpose, perhaps it is time for you to find another discussion.

Awww.... :(

Purpose of this thread: vendors have been selling solid stainless exhaust valves for the LS7 since 2007? Got it - any potential consternation has been averted!

:rofl:

The purpose of the thread, is to illustrate that the use of solid stainless valves as a means of addressing the valve issue in the LS 7, is a method which has been around for a long TIME.

During that time period, no reports of valve failure are documented.

The Quick Theorem "No reported documented failures= proof of solution"

Why not pick up your phone and call some of the major shops and ask them how many z06's that they have installed SS valves in? Should be easy to find someone who has put some miles on this setup....

I have 24K miles on my SS exhaust valves (32K total). Also note 11K of the most recent miles are with a blower on it too. Still going strong.

Wow......Quick must have gone to law school in college.:D Well it's settled for me then. I'm going to keep the new Texas Speed PRC 265,s that came in tuesday and sell my stock heads. With 68k on my 07 it just seems like good insurance. Actually it's seems good insurance for any Z owner....:rock:

I have talked to Richard at WCCH for over 2 hours on this. He has been putting SS values in LS7 heads for over 4 years with no value failures. We are talking hundreds of sets of heads. He feels the PM value guides are a real problem and this can lead to value breakage. My feeling is that some of the OEM values are defective because they are welded. In any event, I will be replacing my OEM values with WCCH. I'll probably go with the SS vs the TI as I am not going to mod the engine with a cam.

In my opinion, a large percentage of the heads Richard has refitted with SS have been run hard and modded. Your typical daily driver Z06 owner is not going to know about WCCH. So while Richard has probably replaced the values in less than one % of the Z06 heads, the sample will be cars that get run hard and tracked.

Mark

:rock:

I spoke to Richard today. I will be going with the SS valves/Bronze Guides and Dual Springs with valve job. He feels this is the best PROVEN way to handle the way my car will be driven. He feels it should be good to go for over 2 years. Thats what I want. :thumbs:

:cheers:
DH

I just want to know how the hell everyone but me seems to be able to talk to richard?

Really? Sometimes I call and want to talk to Deb his Secretary but Richard answers the phone and that always turns into a 30 min. conversation! :D

I did a H/C on my care at 4k miles. The guides were out of spec on the exhaust side. I went with the SS/Bronze set up. After driving another 4k so a total of 8k on the car the heads were pulled. Guides were same as when installed so no signs of wear. I will pull the heads again at 12k but I think the problem is fixed in my case.

One other thing, the second 4k miles was with a fairly large cam.

Quick, you better solve this quick, you only have a few hours

http://sphotos-b.xx.fbcdn.net/hphoto...29125185_n.jpg

And after that (maybe a full race build)?

Solved!

No. A mouse over is not going to get you your answer.

This is the direction that I had hoped the thread would take, and why I am so glad that I made it a point to at least make an effort, to turn the negativity away at the door.

So far, so good.

This is the kind of information we need in helping to determine if indeed there has been a long enough period of time, and enough miles to make some determination as to the efficacy of this approach in preventing valve issues.

To let some tell it, this particular method of approaching the valve issue, has not been around long.

Well, now we can see that it has been around, and that at least one cylinder head expert has been using this approach for better than 4 years, and without a mishap.

When we take into account, that this type work is usually going to be done on cars whose owners will possibly, or even probably, take them to the track, or drive them in the manner in which they were marketed, as well as drive them on the street, then the fact that we are not seeing failures in these setups, during some of the hardest type driving there is, is encouraging.

If these cars are standing up to multiple track seasons, or parts of track seasons, or the occasional trip to the road course or drag strip, and making it back home in one piece, then what does that work out to in cruise control miles?

I think those track miles and quarter mile passes count for something.

And while those cars going into those venues, might not have 150K miles on them, they are still standing up to being driven hard, which is more than we can say for some of these stock cars in here which have failed after just one track day.

Quick, can you post cliffs at the end of your first post...like if there has been any blown ups with ss exhaust valves. Reading novels isnt my thing

Can't do it in the first post.

That's an instant and open invitation to hotheads ready to fly off the handle.

You can't even say "stainless steel" without them going into a fit.

Make that the first thing they read, and they will be in here causing a ruckus and worst case scenario, end up getting the thread locked.

I don't want that type in here while we are having a fruitful discussion.

So I did it in the third post.

Perfect and thank you, 3rd post works as i can count up to 5

Fail much? 3rd post is popcorn(i guess this could be a viable solution)

Sure here it is, I help Ricky:

No. A mouse over is not going to get you your answer.

solved

My third post.

Do you work for Quick as an aSSistant?

:thumbs: :cheers:

It's Quick's thread - I was hoping he'd do the leg work since he started this thread to show us how successful solid valves are. :(

I just don't think "ah ha! someone's been selling stainless valves for years!" is much of a revelation in the context this thread was presented. This thread is actually kind of a joke, IMHO when we realize there's a total void of actual data. I believe data is out there - or at the least it will be - it's just not in this thread.

I'd actually LOVE to see long-term results with solid valves and bronze guides (or solid and OEM guides) - hopefully others will have that information in the future. I'd LOVE to see a legitimate, 100% fix for every person who wants to be past this whole thing and as more people get more miles on their solid valve setups hopefully the perfection is preserved. But right now I see a bunch of hand-waving saying "this is it, we're all saved!" because someone posted a link to a vendor's advertisement circa 2007?

The short of it is, although I expect solid stainless valves to have a superior record eventually - there's still no guarantee that success will be from actually "fixing" an as-of-yet agreed upon cause, as opposed to just replacing OEM parts with a better band aid (solid valves being less prone to shear than hollow stem). It wasn't just a year ago everyone knew the hollow valve itself was the problem. Then maybe those guides are coming from the factory that way? Hmmm, well, now maybe there's a pedestal or geometry issue?

The reason we have an active 1500-post "geometry" thread in this subforum should give some pause before we proclaime the science is settled on this. There's a lot of good information circulating around this forum, but I'm not sure anyone has it pegged 100% given what we know (except for Quicksilver, of course).

But I digress, let's get back to Quicksilver bitching and moaning about how I must be under significant emotional duress because I don't agree with him. :lol:

Just out of curiosity, how long did your stock LS7 go before it popped? I thought you had a few years and tens of thousands of miles with significant track time on the first motor... so what do you think you will gain from this upgrade - a longer maintenance interval?


ETA: I did a search, it looks like you put 80,000+ miles on your first motor right? Does WCCH offer a 2 year / XXXX miles warranty for the proven upgrade?

No. Resulting name calling now, just because you failed to get the point of the first post in this thread

LOL... I agree sure would have nice for an $70K plus car to ever have any of these issues and then everyone have to go out spend time, effort, and money trying to resolve what GM should have in testing. Truly believe this is a quality control issue.

I slipped on the keyboard man and hit caps :cheers:

I stumbled on this during a search:

I lost that in all the back and forth, so it seems Richard (at least at the time) really felt that the valve itself was the issue.

http://forums.corvetteforum.com/c6-z...etproof-2.html

Cool no problem! :rock:

We are 100% in agreement here.

Although many of us argue over details (since we're all looking at it from the outside in) - this is truly a failure from the perspective of GM producing a quality, reliable halo product regardless of the ultimate cause of these issues.

A lot of people are getting burned on this and it's a damn shame.

thanks for all of the information Quick!! You seem like you have done a good deal of research on this issue and really know your stuff. sub'd

Looks to me like you're the one doing the "bitching and moaning" from your statements in "blue" above.

You have no dog in this fight. You're just here. Wagering nothing. You have nothing to lose. The rest of us do.

For people like yourself, who don't own Z06s, and like to theorize and offer your "input" in these discussions, when your position turns out wrong, with your "notions" as to just what is what with regard to this matter, well then it cost you nothing.

However those of us who do own these cars, but who are misguided enough to embrace your thoughts and approach to this matter, when those positions turn out wrong, it will cost us money.

It's easy for you to sit there and talk when you have nothing to lose. It's easy for some of the others still in warranty, and/or racking up the miles on cruise control, to do the same. They ain't running much risk. Someone has their back if worst comes to worst. And then there is you. Nothing on the line, but doing a lot of talk nonetheless.

The rest of us, have money on the table. And following the beliefs of a man who has nothing to lose, with regard to this matter, can result in a cratered engine block.

So any Z06 owner, reading "Random's quotes", needs to keep the above in mind, and proceed accordingly.

Some of us have to act to protect ourselves against a broken valve. You, we'll you don't. You don't have any stock LS7 exhaust valves to break.

You have the "luxury" of theorizing and pontificating on this matter, because you have no LS7 to lose.... Not even a stock one. Let alone a modded one.

So whether or not you "don't agree with him", is meaningless. When you are ready to put your money where your mouth is, and put a completely out of warranty, with no prospects whatsoever of a free repair, LS7 based Z06 on a track, or a drag strip, with stock exhaust valves in it, then come back.

Few in here now, choose to continue to do it, because of this valve issue. Confused Garage, is one of the few people in here who has posted up documentation that he has done, and continues to do it. Howie has done it too, but now even he has decided to no longer roll the dice waiting for them to come up craps, pressing his luck, because he knows that the next LS7 motor he pops, will be on him. So he is taking steps to keep that from happening.

But you, well the next motor, won't be on you. You aren't taking any risk. So until then, all I see you doing is just talking at the poker table, while wagering nothing.

If its just a quality control issue, then why are the ZR1's having the same extreme guide wear problem ? ZR1 blocks don't have Z06 heads on them.

Probably the same vendor did the LSA/LS9 heads as the LS7 heads would be my bet. It's a QC issue has to be it's to random

I got him on the 3rd try and sent him 2 emails. I called him when he said he would be available in the second email.

It was worth the wait and he answered all my questions.

He also said they were going to be very busy for the next week or so as they are installing replacement CNC machines.

:cheers:
DH

Rich

I gotta keep the motor untuned so I can run in the MODIFIED CLASS of the 2013 CORVETTE CHALLENGE, and hopefully repeat my 1st PLace Finish :rock:

I'm going to redo the heads with the WCCH valves and guides. And then I'm going to track it for 2 years. And if it doesn't blow up I will pull the heads and do it again :D

I got 30K miles and 2500 track miles and don't want a repeat of my backward slide into turn 8 at WSIR :rock:

:cheers:
DH

Good for you Howie.

You have one in here implying that since you got 80K plus miles and track miles out of your last motor on the stock valves, that you should be able to get the same with this one.

:rolleyes: Of course if that turns out to not be the case, then it won't be him in the car during that "backward slide into turn 8 at WSIR" with his life on the line.

Folks thinking like that, are still talking the same "we don't know if they are a fix yet" talk, while you have your feet in during that backward slide, and praying that you don't get T boned.

You're going about this the right way Howie. :thumbs: :cheers:

87K miles and 30 track days (I didn't keep track of the hours/miles like I do know). But there is no guarantee this second motor will get any where near that.

Richard actually said 100K the way a use my car when I asked if it would last 2 years. I hope I don't have to ask if he warranties what he told me. :D

He said he was basing this on his years of experience observing SS/Bronze that get rebuilt.

I have read every post in every thread on this topic. I have heard enough and seen enough to be confident that SS/Guide/Springs will not hurt the motor or impede performance. I know the stock setup blows up and put me in an oil slick going backwards at 120MPH. I'm willing to try something different. :rock:

:cheers:
DH

And many familiar with your story, and don't want to end up doing their own version of what you did, are too.

Those who don't want to do their own version of what you did that day, and are actually serious about avoiding such a consequence, I'm telling you, you need to take heed.

Pay attention to what has worked so far in preventing it. Instead of listening to people trying to dismiss that which has in fact worked so far and with no description of failure, with their double talk, and theories when they, themselves, have no chance of a failure, and nothing to lose.

Especially while stock exhaust valves continue to break, and their incidence has not let up at all over these years.

I'm still looking for a description of the head of one of these solid stainless valves snapping off, over the better than 4 year period they have been used in here, and either I'm not looking hard enough, or there are none.

Hope you don't mind me cluttering up your thread Ricky. But here are the videos that some may have not seen. I was extremely lucky that there were no walls around. Also luckily for the other drivers I was so fast that no one was near me and hit my oil/coolant slick at speed :willy:





:cheers:
DH

i have checked my guides and rockers after every track event and no issue. The ss valves and bronze guides are a favorite of many track cars here in AZ.

That's not clutter Howie.

Your videos might stimulate someone else to not take the nonsensical, if not outright foolhardy approach of "we don't know if this is an acceptable or effective means of prevention yet, because it's too early to tell and there aren't enough miles on the cars with them", and end up into a wall at a drag strip, or a road course, or a Jersey barrier on a public road, with a totaled car.

Especially when people have been doing this for going into 5 years now, and with no reports of failure.

So no, your videos are not clutter. They might make someone else decide to take steps to protect themselves, instead of grasping at straws trying to argue that not enough evidence of effectiveness is in yet.

You have something like this happen again Howie, and the first thing people ask you is; "Howie, after this happened to you the first time, from a dropped valve, why didn't you do something about it, like change to a stronger valve, especially after people have been doing that for better than 4 solid years and have not had one fail yet?'

And you respond: "Well, there wasn't any evidence out there, and not enough mileage on cars with SS valves in them to convince me that I would be lessening my risk. No hard core data that it was anything other than a bandaid fix. No double blind studies. And it didn't get to the root of the problem, which neither myself, nor anyone else knows yet. Also several people have gotten 100,000 street miles out of stock valves. So the fact that it had already happened to me, and almost cost me my car and personal injury before, wasn't enough to make me change anything, because 4 years of no reported SS valve failures, well, that doesn't mean anything. Doesn't count for &^%$. Shut up with all of the questions, make yourself useful and send me a flatbed"

OK. :lol:

Likewise, someone says to me; "Quick, you saw what happened to Howie. Why didn't you do something?"

If I respond with the same nonsense above in bold, I come across the worse for it.

The fact Quick went from shaming people and blaming people for breaking the valves into tears while vehemently defending GM, to posting this info makes me believe this is a possible solution.

I am continuing to go through the archives of the forum looking for an example of a snapped off stainless steel exhaust valve head, and still have yet to find one.

If people were missing shifts, and snapping the heads off stock hollow stemmed valves, then how come when they changed to solid stemmed stainless valves, their driving got better and they no longer missed shifts and snapped the heads off of exhaust valves?

So yes, the fact that we have gone this long, with few, if not actually no reported failures of stainless valves in here, indicates to me, that this approach very well could be the remedy and likely is.

If 4 years is not effective, then what is? 10, 20?

If you watch, there is a pattern amongst the diehards.

First, there is a denial that there is even an issue.

Along with that, is a pattern of denying that there are effective remedies, or that they are even needed, since no issue exists in the first place.

Then a forced admission that there is something amiss. This happens a few of different ways. Eyewitness, personal experience, reliable source(s).

Bu to large extent, all who were not convinced that something was up, became convinced following GM's statement back around Labor Day. This forced all but the toughest diehards to abandon prior positions, and finally admit that there was a problem. However believe it or not, there are still those who insist that GM's message, is not authentic, and did not come from them.

Some like myself, figured it out well before that point was reached though.

Next, there is the grudging admission that something was indeed up. It comes, but there is a continued staunch denial that those in the past, were actually "right" and that the issue was the valves themselves. Hand in hand with that, goes the continued denial that that prior remedies, such as stainless steel valves, were warrantied, or "proven" to be effective.

In that ultimate admission that something indeed had been wrong, goes the approach, that "Yeah, something was up.........but it wasn't the valves. Nope, wasn't the valves", they don't want to admit that it was the valves. To do so, would be an admission that those back years ago, had been right. So they can't admit that it was the valves.

So something else gets blamed. Something "new". Something BIG. The hollow stemmed valves are too simple. "Shade tree" mechanics can change those out, no trouble. No. Need something else to blame. The more technical and fancy the measurements, angles, drawings to scale, and diagnosis and such are, the better. It was..........GEOMETRY, yeah, that's the ticket, it was geometry......wasn't the valves themselves, it was geometry. So addressing the valves is and was a wasted effort by anyone who took that approach.......because it was geometry, all along it was geometry. And you can't fix geometry by changing valves"....you....you guys who changed your valves, well ...you just wasted your money, and made your valvetrain heavier.....yep, that's what you did. because this problem.....it's geometry...yep, geometry."

Meantime, as I have uncovered, SS exhaust valve swap has been employed for better than 4 years in here now, and nary a report of one failing.

So the problem that the diehards have is that they cannot point to an example of this remedy failing in better than 4 years in here. And they desperately want to. But they can't.

So they do the next best thing. They try and argue that it's "too early to tell if it's a 100% fix". Not enough miles, and other talk. Well, it's been 4, going into 5 years since the first ones were done!!!! The C6 Z06 has only been around for only 7 years. So that argument, won't hold water.

If it was solely "geometry" well then how come everybody in here who had their valves changed, suddenly not only miraculously became immune from "missed shifts", but also became immune from broken valves due to "bad geometry"?

How about the rest of the car, going to improve the suspension or replace with stock parts as they wear?

Well I did put DRM Bilsteins after I passed the 100K mile point. With 117K miles now and close to 50 track days my car seem like it is getting lower. Hope I don't have to replace the leaf springs. Keeping everything as stock as possible.

Hope this wasn't a trick question Rich :lol:

When its done we can compare engine sounds again. And see how she revs up. :thumbs:

:cheers:
DH

"What I have found after so far looking...".
 

..or more aptly, "Why those looking for examples of solid stemmed stainless exhaust valve failures, are not likely to find any."

Head work in the LS7 was an evolutionary process. Early on, it was felt by some that there was not a lot to be gained in terms of power, by porting the stock heads.

At around the end of 2006, at least one company, LGM was porting them.
http://forums.corvetteforum.com/c6-t...post1557481213

People were still using the stock valves however, a few reasons for this.

1. As failures occured back then, they fell into two basic categories. Valve related, typically blamed on broken valve springs, and oil starvation.

Early stock failed LS7s were sent back to Bowling Green so in many instances, the owner would not know just what the cause of failure was.

Furthermore, some of the "valve spring" breakage failures, were no doubt actual broken valve head failures. But of course an owner may or may not have been informed of that.

2. As a result of #1, no one had much reason to change out the valves in those rare instances where head porting was even done.

In following the archives, it becomes apparent that the valve issue continued. It of course showed up in stock cars, but modded cars were hit especially hard.

Bolt ons prevailed of course, but the popular internal engine mod early on, was the "cam only" setup.

Around the time of the tunes, and cam only setups, the exhaust valve droppage issue in those modified cars accelerated. They all had in common the fact that they were tuned.

As time went on and more shops offered LS7 head porting, the rash of dropped valves in the cam only setups had increased. This led people to try new exhaust valves in their cars slated for a heads and cam upgrade. Titanium and Stainless Steel were used.

So it is worth mentioning at this point, that these heads upgrades which included porting and valve exchange, were never intended for otherwise stock cars, as we are seeing now. For example now, we see forum members in here with no desire for additional power, doing their heads for no other reason than to address the valve issue. This was practically unheard of back then.

The cars having their heads upgraded, with titanium valves, were cars which were also likely going to have cam upgrades as well.

*****This is the reason why you won't find early cars with upgraded exhaust valves, be they titanium or stainless steel, with a lot of highway miles on them. This procedure, was not done for highway cruisers. It was done for cars which were likely going to be street raced and/or track raced.

So when someone says that the cars which have had this done to them, don't have any miles on them, that might be true. But a big part of the whole point in doing the cam, and heads upgrade, along with changing out the valves in those early days, was so that the car could be beaten on, with little fear of a valve failure, as it was becoming apparent by then, that valve failure was a common failure, especially in modified cars.

We have now made it to this point. A point where head work, is not always done so much for power, as it is for preventive maintenance.

Whereas the primary purpose for head work back then was to increase power first, and then later on, improve reliability, we have come to a point to where the goal of head work, for some, is to improve reliability, with little to no regard for increasing power.

The reason why we have progressed to this point, is because of those early LS7 internal engine modders, looking for additional power, starting first with

1. Cam only setups.

2. Then moving to heads and cam setups but staying with the stock valves, doing port work and milling only on the heads.

3. Experiencing valve failures in the cam only setups, and heads with stock valves and cam setups.

4. Including valve upgrades in the head work to combat the valve failure issue.

Cars with the above work, are not very likely to be high mileage cars.

I am one of those who had WCCH heads done as a preventative effort, and I think another reason you see more head work for prevention is due to the fact we are now seeing warranties expiring en masse. I had no reason to believe GM wouldn't honor my original powertrain warranty while it still applied.

The expiration of my warranty was my decision point. At that decision point, I had three courses of action 1) Wait and do nothing hoping for definitive proof one way or the other 2) install WCCH Heads with SS valves 3) Sell the car. I chose not to wait an unknown amount of time for someone to figure out beyond the shadow of a doubt what the problem was (or wasn't) while I was sitting with no warranty. I also love the car and want to keep it so I have no desire to sell.

Extended warranties are not available or honored here in Germany so that was not a 4th option (for me). If the problems were QA/QC issue, I also had no way of knowing if I happened to get one of the "bad ones", no VINs or castings or anything to cross reference. I also knew that the failure, if it occured, would be catastrophic to the ~$15k+ engine.

So over a year ago, I accepted some knowledge risk considering the lack of documented testing, and did WCCH Stage II heads with SS valves. To mitigate some of that risk in my own mind I researched the feasibility and ability to control heavier valves. Despite lack of testing evidence, I found no reason why it was absolutely not possible to control a heavier valve through use of proper springs. And to that point, the springs that WCCH uses for their SS valves are all stronger than the PSI1511 springs used in the often quoted Katech article.

Finally, if someone figures out a better solution or GM provides a fix... Guess what? I can implement that solution in the future too. If SS valves prove to be a band aid only, well maybe my "band aid" was enough to bridge the time gap between my expired warranty and that future unknown date where we figure out the grand unified theory of LS7 head failures.
I will not tell anyone directly that they should or should not install SS valves, but I will be more than happy to share the thought process behind my own decision to do it. Note, no where in my decision cycle will one find fear, panic, or a belief that the sky is falling :lol:

:cheers:

:thumbs::cheers: Excellent post, logical approach, and as a result you, like others, add to the data base of cars still running strong after doing what you did.

You mention your warranty, and that you "had no reason to believe GM wouldn't honor my original powertrain warranty while it still applied."

I had an aftermarket warranty, and had good reason to believe that the warranty company possibly would NOT honor my warranty if it applied.

This too, was my decision point.

Out of warranty was a big factor in my decision as well. :thumbs:

If the failure mode left one with a $2-3K I wouldn't be doing anything. But its a $15-17K bill if your not a mechanic by trade. :(

:cheers:
DH

:cheers:
DH

Sounds good on comparing engine sounds. As far as the suspension, you may also want to replace all the bushings at both ends as they are probably shot by now. Heck, might as well have the whole system checked for wear ( A-arms, steering linkage, sway end links, ball joints, wheel bearings). I think the DRMs are a little shorter than the stock shocks and that might be what you're seeing in your (lower) ride height (unless it has been getting noticeably lower after install).

Even if you are a mech by trade, a windowed block from a dropped valve is still going to be very expensive just to get the replacement block, heads and internal parts. :willy:

Nothing wrong with trying to make it better - but in all of the arguing we sometimes forget that your doomed OEM setup withstood a tremendous amount of abuse even if it could have been designed differently (or use better parts/QC). Kind of like supercharging: the OEM setup may not be appropriate if you decide to go beyond the factory envelope. I'm not sure where the line of "performs as expected" is drawn, but my understanding is that 30 days of track time will be well beyond what any traditional track engine sees before a tear down.

In your case, it makes sense. In someone who doesn't track their car (and has good geometry, etc), is there a cost-benefit of changing out the valves at 20,000 miles if there's a reasonable expectation of another 60,000+ miles of use with normal driving?

Did Richard differentiate between racing and daily driving when he said the solid valves/bronze guides should be good for 100K miles? I'm curious as to what most professionals would recommend with a healthy diet of road courses?

I've got some Solid SS exh. valves in My WCCH heads done back around 2009. But they re-used the stock guides.

It'll be interesting to see what shape the guides are in. I'll get to it after I'm done working on my camaro this winter.

:iagree: I, too, was amazed at the number of miles and track sessions DH got out of his car. I actually thought it was going to go much sooner. The amount and type of usage he got is actually a tribute to the design of the LS7 and its durability given that it is, after all, a street engine. I think his is doing the right thing, given what is known now, to try and ensure his (new) engine lasts a couple of years, and his plan to renew (again) afterwards is sound. Given his usage of tracking in the Corvette Challenge series here in SoCal, and DDing to/from work, he will probably be the best test case we will have to see the durability of this particular "fix". Just hope it lasts the two years and doesn't fail first. That would be a particularly bad data point.

I've always taken the approach to trust the experts on this type of thing.. and aside from Katech, most of the other shops or head builders I've seen are recommending the SS valves, so if I were to do head work I'd trust them and go that route.

So Katech recommends against solid valves cuz they're haeavy?

Yes, and they are OK with the factory two-piece valves, properly installed

..and because of that they are now offering a coated Ti exhaust valve that is lighter than the factory valve and about $1100/set for forum members should they choose to go the light weight route.

Interesting...so Katech is against solid stainless steel but just about any other shop is pulling for them...and this is right when i was about to get PRC heads with ti intake and ss exhaust...

They are OK with SS exhaust valves in some FI engines, if I recall correctly.

If Katech doesn't recommend it I don't use it or buy it!!

Are they really ok with the factory hollow neck sodium filled exhaust valves?

Do they state the OEM exhaust valves are ok for use in two extremely different applications, the street application and the track application regardless of the longevity desired from the valves. It would be logical that the street application would be easier to answer ok. The track application could be ok if you accept a short rebuild interval and verify EGT temperatures. If one is going for longer rebuild intervals with track use, I would expect a different answer if they were specifically asked. Like Titanium.

SS valves you say? In an LS7? Blasphemy!



:rofl:

For track use they always recommend close to racing time for going into the engines. However, they claim that the GM racing team used factory stock exhaust valves in the C6R and previously in the C5R.

They have developed the coated Ti exhaust valves for the Corvette racing program, though. This info has been posted here on the forum by Katech.

im with quick on this, hes right on. thanks man! :thumbs:

No problem. :thumbs::cheers:

You can't argue with better than 4 years of success and no failures.

How many cars in this irrefutable success story again? What was the most mileage?

Quick

Keep in mind that with new solid stem valves, the guide and seat are also worked, and springs as well. So while these worked heads are proving to be reliable, what's to say that if OE valves would have been uses, they would not be just as reliable. Remember, you asked for folks to keep an open mind. Do you have an open mind?

Any number, given to you for either question, would still not be enough for you to admit the fact that solid stainless valves have proven to be a viable alternative in the management of the LS7 valve issue.

So aside from the fact that you own no Z06, there is the above fact, and so really no reason to answer those question beyond that which you have already read in the thread and elsewhere on the forum.

How many failed stock hollow stemmed valved LS7 motors in here can you count?

How many with rebuilt heads using solid stainless valves?

So for those of you following this thread, if you want to know why I am short with guys like this, who I might add, do not own Z06s, and are "safe" from this problem, if you want to know why I don't, and why you shouldn't listen to rhetoric like what he has spouted in here so far, take a look at the pics below.

And after you have seen enough of the following, well it makes you stop and think that you don't want to be next, and if you weren't open minded on this issue, and you own one of these cars, well then things like the following, tend to open it when you realize that you could be next.

But this is why I don't listen to Random's ramblings about what is and isn't "proven". Below follows some of the "proof" that I needed to help change my mind on this matter from Random's way of thinking. I am convinced that he thinks the way that he does, because not being a Z06 owner, and certainly not one who tracks his Z06 out of warranty, he is at no "risk" whatsoever of being next in line for the following. So he can "talk" all he likes. He is carrying no risk.

Say that part in bold again, so that the doubting Thomases can hear it:

You say while these worked heads are doing what????? What was that word you used????

:smash: Thank you. But now you do realize that there are diehards who say that nothing so far has been "proven".

But you said what about these worked heads??? They're doing what???? :D

Proving to be reliable....:thumbs::cheers: That's all that anyone can ask in this situation.

I'm with you Michael_D. Yes, they are proving to be reliable. And that's my point. You said it, I agree with it. "these worked heads are proving to be reliable.

Nothing. But like Eastwood said awhile back, "Do you feel lucky?"

The penalty for being wrong about the OE valves is about $15,000-$17,000.00.

Watching other LS7 motors pop, from broken stock hollow stemmed valves belonging to people who are no different than myself, don't live any better or worse than I do, say their prayers, go to church , and pay their taxes, just like I do, made me wonder why I would expect to be lucky and not have mine pop, while they weren't.

What is it that I got, that they don't, which would make me immune to, and prohibit my being the next sad story on the "list of popped stock motors due to a dropped valve".

Nothing. And thats why I made the move that was right for me.

And the one I made, I made because .....

I believe it. :thumbs:

Any time a man can go from vehemently believing that no issue existed, to examining the actual facts, counting the continued failures, weighing the evidence, and deciding that one definitely did, and does.....yeah, I'd have to say that I have an open mind on this matter.

You still don't get it and i no longer have the energy to converse with you. You are not listening to me. You do not wish to learn or understand.

Unsuscribed....

Not listening to you??????

Michael_D, I'm not only listening to you, I'm agreeing with what you say. What else do you want????

I'm not sure what the "unsubscribed" was for. But whomever subscribes or unsubscribes, the facts are the facts, and indeed, you spelled them out.

That is the crux of the whole thread.

Before I got the DRM everyone said it wouldn't affect the ride height. I didn't want it any lower cause of fear of tires rubbing during track events. Now everyone seems to indicate that they do in fact lower the car. I noticed the difference after installation. I still have to take my car to your suspension guy and have it gone over.

:cheers:
DH

We discussed exactly how I use the car and how much track time it sees. He said 100K miles.

:cheers:
DH

Rich

I was going to sell my present heads (2011 with 30k and 2500 track miles) to pay for the ones I have bought (2006 with 16K and no track) and are on the way to WCCH. But after checking them out a little today I may keep them and use them for my next refresh in 2 years time. I will have the guides measured on them when I get them off. Here is data from today incase you miss it in other thread I posted in.

Pulled my plugs today. Mechanic said they looked great. I asked why the end of the threads on a couple were black (#7, 8) and he said it was fine. They were dry and all the tips and porclain looked the same on all plugs.

Pulled passenger valve cover. Noticed there were white paint stripes on the springs? And around #4 springs there looks like an area where someone took a grinder to (and it wasn't WCCH :D). There was very little to no side to side movement of the rockers. Much tighter that I thought they would be.

Checking geometry. First pics are of exhaust valve/rocker #4 cylinder. Used black sharpie on valve end and pic didn't come out too good. But it looked just like the red witness on #2 exhaust which is next in the pics. There was no wear on the edges of the valve at all. The rocker pad wear patterns were mostly rectangular. There definitely was no burnt crescent.

All cylinders compression tested to 200-210 lbs. So I am confident my bottom end is good. I also think my heads are good and will be asking top dollar when I sell them with the rockers.

http://i20.photobucket.com/albums/b2...psc2c598b6.jpg

http://i20.photobucket.com/albums/b2...ps04b0add4.jpg

http://i20.photobucket.com/albums/b2...ps5fb873d3.jpg

http://i20.photobucket.com/albums/b2...ps0022f975.jpg

http://i20.photobucket.com/albums/b2...psad0047e1.jpg

http://i20.photobucket.com/albums/b2...psa9976331.jpg

http://i20.photobucket.com/albums/b2...psbfe96a19.jpg

http://i20.photobucket.com/albums/b2...pse03d5cf2.jpg

http://i20.photobucket.com/albums/b2...ps3f552dfd.jpg

http://i20.photobucket.com/albums/b2...psafe07bce.jpg

http://i20.photobucket.com/albums/b2...ps7fe7ca1e.jpg

:cheers:
DH

I asked Richard (WCCH) about these and his new DelWest exhaust valves which will be available at the end of the month. Right now he said use the SS because it is WELL PROVEN :thumbs:

:cheers:
DH

Their TT air attack packages use inconel exh valves and advertise a 7000 rpm redline. Katech managed the weight in that build with a custom cam profile with gentler ramp rates. It is also on their website.

Well, if in better than 4 years, he has not had these heads coming back to him with broken valves, then they must be proven.

He's certainly not lying to you, and would no doubt be unsuccessful even if he tried, because if he had been selling junk over these last 4 years, that was falling apart, word would have gotten around. Especially in your neck of the woods, because he is just, what 35 or so miles away from you. Word would have also spread in here, as well as on the other LSx fora.

You're on the right track Howie. Literally and figuratively.

You've done more research, and picked Richard's brain harder than I did when I was having my own heads done. And I asked him every question I could think of, and in multiple conversations.

And looks like that 6yr old with the grinder has found his way to GM. Or maybe he started at GM and WCCH hired him.:rofl:

Either way, I don't think that anyone was ever going to see that scuff mark without going to some effort.

A stock bare cyinder head castings retails for $1381.47 per head, so over 2700.00 for the pair with no springs, retainers, and certainly no fancy moly coated valves in them.

So a word to the wise, thinking aftermarket heads, ask yourselves how someone can sell you a set of tricked out aftermarket heads with moly coated titanium intake valves in them, SS exhaust valves, dual springs, titanium retainers, and fancy port work, for $3000.00 or less without cutting corners somewhere, when a set of bare stock castings would run you over $2,700.00 at your dealer.

Thats also another thing, I talked to Richard at WCCH too. He is very easy to talk to and I never had a problem reaching him. It is too easy just to pick up the phone and call and ask questions if you are serious about doing the work. He didn't try to up sell me into anything either.