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: