HyperX

Been running my Z06 for 6 months now with SS valves, heads and other goodies and it seems rock solid! I have not been checking this sub section that much, but has there been even a single report of dropped SS valves?

LFZ

A few so far...

ClarksZ06

One of the maybe 2 failures was due to the motor having worn out stock guides. The SS valves were literally wobbling around in the guides they were so bad. Any valve would fail in those conditions. SS, hollow, or titanium.

The most important key to the fix is good machining and quality durable parts. I would only have the most experienced shops do an LS7 head

'06 Quicksilver Z06

There are 3 descriptions of failed SS valves that I can find on this forum..

1. Madsen, who is referred to in the above post by Clarksz06

2. 1stZ whom I will familiarize you with in the following text.

3. Corvee, who shows a pic of a bent SS valve with the head snapped off it.

1. Madsen. Broke a stock exhaust valve, running a cam setup, done by an unknown shop, but apparently using stock exhaust valves.

http://forums.corvetteforum.com/c6-z...post1571835806

Following that incident, he alludes to his rebuild following the mishap, in the posts below.

http://forums.corvetteforum.com/c6-z...post1569346169

http://forums.corvetteforum.com/c6-z...post1568963370

http://forums.corvetteforum.com/c6-z...post1568881318

The description of the failure incident a few years later of a rebuild, was made in the following posts The second rebuild was using SS valves.

http://forums.corvetteforum.com/c6-z...-at-strip.html

http://forums.corvetteforum.com/c6-z...the-count.html

The carnage was evaluated here, and a description of what was found, i.e. stock valve guides, was made in the following post.

http://forums.corvetteforum.com/c6-z...#post158479550

The following post indicates that Madsen thought that he was on bronze guides in this particular engine.
http://forums.corvetteforum.com/c6-z...post1584068005

2. 1stZ. Also failed a stock exhaust valve before having his engine rebuilt. After his stock valve failure, he describes his subsequent failure, the rebuild failure, in the following posts.

http://forums.corvetteforum.com/c6-z...-the-road.html

http://forums.corvetteforum.com/c6-z...post1574525676

http://forums.corvetteforum.com/c6-z...post1574483942

From my perusal, and from what I can gather, it appears to me, that both Madsen and 1stZ were customers of the same shop at one time or another. I encourage anyone else interested to look at the posts as well as they may come up with a different assessment.

That said, I can find no mention of the word "bronze" being made by 1stZ when I search his posts. Again, I encourage anyone else to search as well, but I could find no instance.

3. Corvee. Corvee mentions a SS valve failure, and shows a pic of a bent SS valve with the head off of it.

http://forums.corvetteforum.com/c6-z...post1584770192

This also happened in a rebuild following a stock failure.

http://forums.corvetteforum.com/c6-z...post1577078598

http://forums.corvetteforum.com/c6-z...ged-build.html

What I gather from the 3 described failures of SS valves here, is that at least one of the cars referred to above, was said by the person who examined the damaged cylinder head, to be running stock valve guides, which were found to be shot, when the engine was torn down and inspected.

The second car, I could find no information on what valve guides had been used along with it's reported SS valves. Furthermore, a perusal of the owner's posts will indicate that this car was beaten on quite a bit, with multiple 190mph runs, finally failing at 150mph and during a time when the owner knew that the engine needed to be overhauled but admits that he did not have the funds to do so, and kept beating on it anyway.

http://forums.corvetteforum.com/c6-z...post1574525676

http://forums.corvetteforum.com/c6-z...post1574483942

The third car, shows a bent valve, missing it's head, said to have been due to "valve bounce".

Currently, there are 283 members of this forum who say that they are running a heavier than stock exhaust valve, of one material, type, solid or hybrid hollow/solid or another.

What is commonly referred to as; "The Fix", is widely held, among many professional shops as well as enthusiasts, to be the use of solid stemmed stainless steel valves and bronze valve guides.

GMuffley

^^^^^^^^^^^^^^


Wow! Great info.

propain

You got way to much time on your hands Quick.


Short answer... yes.... 3 failed. 1 valve stem beat to hell too. (The thread was pulled)


You can blame it on whatever you like... if you don't fix those guides you are not safe even with the SS valve. Also you add the bounce factor which adds unknown results at this time. The 200+ list is mostly made up of stock cars and who knows if they are DD or garage queens. Also most of them have been installed for less than 6 months so that's not exactly a good example of success... yet.

"The Fix" was used by many to simplify what some consider the proper course of action to address the problem. Its more of a slang term than a meaning to be taken literally. We are far away from officially calling it "The Fix".

GMuffley

Quicksilver is the Rainman of valve issues.

Madsen

Thanks for all the you spend on these threads Quick.
You tanitaious tracking has helped us a bunch.
Thanks Rickkie

'06 Quicksilver Z06

As time progresses, it becomes more apparent that you and I are perhaps not that far different in our opinions on this matter.

I agree wholeheartedly, that with shot guides, any valve is likely to eventually fail.

So that introduces questions about the selection of materials for one's guides.

Many recommend manganese bronze for it's lubricity and more noteworthy, it's wear characteristics.

Thus far, it has come to pass that even fixes using the stock valves, as long as the guides were changed to bronze, have survived, though like you mention, it is still early, and that sample is even smaller than the one you refer to.

A wise man once said, "every solution, has a problem."

So true.

A fix, involving just the guides, but keeping the stock valves, which are "suspect" in the eyes of many, based upon the number and graphic images of failure instances, is a "problem" for some.

A fix involving the guides, but stronger and heavier valves, is a problem for some, due to concerns of potential ill effects from running the heavier valve.

So no "solution" dreamt up by human beings is going to be perceived as not having it's own "problem" by some observers.

Among the questions asked then become;

1. As the potential problems associated with going any particular route go, how much am I at risk for them?

2. Knowing that all options with regard to managing this problem carry risks, which risks are more tolerable for me and which risks are less tolerable for me?

For many in here, myself included, the potential risks of doing a fix involving just the guides, and sticking with the stock valves, outweigh any risk associated with replacing the guides and going to a heavier and stronger valve.

So far, both approaches are showing success, but in terms of numbers, in here, we're talking 280+, going the heavier valve/bronze valve guide route vs only about 20 going the bronze guide but stock or titanium valve route.

In terms of "time" though as you mention, both approaches might be considered "young" by some.

However, the bronze guide/stock valve approach is arguably "younger" than the bronze guide/solid stainless approach.

Hope that helps anyone reading it.

BTW, I'm talking about "fixes" only.

So before anyone comes up with "but 26,000 plus cars are running fine with the stock valves, the stock components are fine", I'd point out that I'm speaking of those who have either discovered problems or are concerned about problems, what has worked and what is working for them.

ClarksZ06

I'm pretty sure the one stem that was beat to death that you keep referring to was that of CF member Nicks02Z06. That rev valve had ~1,500 miles of use on it. All his other SS valves were ok. I think that shows to be a Quality control issue with that single valve and should not be used as an example of SS valve failure in the LS7 reports

propain

Since the thread was pulled and the problem covered up it is impossible to come to any conclusions. You say QC, I say a possible issue with bounce. Neither of us will ever know.

ClarksZ06

Bounce damage within 1500 miles with a comp cam with reasonably gentle lobes. I Highly doubt it. There are many of us here with SS valves with 10-20 times that mileage without issue.
I think your really hunting and hoping for a problem this time.

propain

I don't hope for problems, only looking for answers. Covering up a thread about 1 hour after it was posted doesn't look good and leaves plenty of room for interpretation. I don't have all the answers and either do you. Where does it say only 1500 miles? I don't see the thread with all the details to make a proper determination of the problem.


Seems like you are consistently hunting for a problem with me however. I see you gave up on your last attempt.

SSMOKE

Thanks Quick. Being one of the many that spent thousands on "THE FIX" I count on your thorough CLIFF NOTES and ongoing evaluation of valve train combinations. BTW My car is running like a crazy fast CHAMP!

Pb82 Ronin

Guides are the secondary cause of the valve issues (not saying they aren't an issue)...but think further back in the chain of events leading to a valve failure and ask yourself what would cause a guide to wear out prematurely? There my friends is the infamous cause...

Mark2009

The logic of your argument is fatally flawed.

And personal attacks don't improve it.

JoesC5

I hope my new PRC265 heads with Ti intakes and SS exhausts with dual springs(up to .675" lift) using my stock cam, is the fix. From what I've read in other posts, bounce is not a problem unless you go above 6800 RPM. Very seldom do I go above 6500 RPM, so I'm not worried.

ClarksZ06

This is not personal. I'm just sticking up for something that is working while your fudging reasons that its not. Like Ricky always says "the track record speaks for itself"
I'm sure you can PM Nick and get more of the details on the bad valve. I'd be curious to know the final outcome. I'm betting they put a new SS valve in its place.


Mark, your so silly

Mark2009

And more personal attacks... OMG, is that the sum total of your argument on the issue?

propain

You continue to make it personal directing your posts at me rather than just attacking the facts. This is the 2nd thread you have done it in. Seems like you have an axe to grind with me. Stick to attacking the facts.

I have no issue sticking up for something you believe in but don't accuse me of fudging anything. I am point out the facts about what we have seen thus far and you don't like it because it contradicts what you are sticking up for.

You speak of track records speaking for themselves yet the MAJORITY of the people running the setup your defending have less than 6 months on it. Hardly a track record.

The post I am referring to came from someone named Sm5654. I don't know who Nick is. I think you possibly are confused about what I am referring to.... AGAIN.