Gary '09 C6

that LT5 was a work-of-art...I should have bought a (used) C4 ZR-1 years ago, but didn't.

thanks for your other comments...

Beach Bum

GM made a profit of 4.9 Billion Dollars in 2012.... pretty good stuff if you ask me.

I believe we have something like 29,000 Z06's including the low production late years. Lets say at an average actual cost of $ 2500 to fix them. (I doubt it would be that high of an actual cost, or even close, but lets exaggerate for sake of error's on the high side)

2500 x 29,000 = $ 72.5 million Total cost.... which is approximately 1.4% of last years profit. That is assuming all 29,000 cars came in for the fix and assuming its $ 2500 each and further assuming that the late years have a problem.

GM, in my mind has sacrificed a big old handful of loyal Corvette enthusiasts in the name of 1.4% (At the most) of profit.

Honestly, I have no idea why somebody who is aware of the situation would buy a C7.... fool me once, shame on you, fool me twice, shame on me type thing. No way I'm taking a chance on that new LT-1 motor...... no way.

http://www.usatoday.com/story/money/...arter/1918293/

Gary '09 C6

...of course, the cynic in me says GM figures the above group will just die-off soon enough, so why bother...

Mark2009

I don't disagree with your numbers, but I'm not surprised nor particularly pissed. It is what it is... suits run the company, not engineers or gearheads. Some of the suits probably want to put a V6 in the Corvette (maybe rename it the Mustang ), and in years past they put a Vega steering wheel in the Corvette. All things considered, I don't think we're doing too bad.

I bought an LS7 full aware of the valve issue. I wanted the engineering the car provided, and considered some potential $3K in head work the price of admission. The LS3 and the LS9 did not interest me, but that's a matter of personal preference.

If they make a Z-something C7 that interests me in the future, then I might upgrade... even if a head job is the price of admission. But I suspect the LS7 is going to the the NA king from this point forward. But NA or cubic inches isn't for everyone, and that's fine

pkincy

I worked for a major financial corporation much of my early career. In the late 80's a large problem due to the drop in interest rates began to appear. The CEO commissioned a study of how much it would cost to just "fess up" and fix it. The answer was about $400 mm. And he very seriously considered biting the bullet and just fixing it. Ultimately he did not. A few years later I was talking to him and he wistfully mentioned (he was no longer CEO) that he had gotten that decision mostly wrong. It ultimately cost that Corporation $4-5 B in hard dollars to fix that problem and likely 2-3 times that amount in lost Good Will.

I certainly don't know that this is a problem that rises to that extreme, but I guarantee you Johnson @ Johnson was very glad then CEO James Burke pulled all their Tylenol in 82 immediately upon hearing of the first of ultimately only 7 cyanide laced Tylenol tablets.

That is a lasting legacy for both he and the J&J companies.

Dirty Howie

Mark

I don't know why anyone would have a problem with accepting the fact that GM engineers are fallible? Certainly history is abound with such proof. I remember a very cool looking car my dad got when I was a little kid....the Corvair. How many GM recalls have there been over the years .... none from poor engineering?? But ultimately, it is GM who is responsible as they hired the engineers and manufacturers.


DH

Mark2009

Probably because it is not a demonstrated fact with regards to this issue. That would be my first guess if I was interested in this line of hypothetical discussion. Since I'm not, I think this horse has suffered enough abuse

JoesC5

My sentiments exactly. That new Vega I purchased in 1970 never burned a drop of oil because of the superior engineering at GM. LOL. And because the GM extended warranty on those cars was a SECRET, I never knew they would replace my engine with up to 50,000 miles on it, because of the excessive oil burning(a quart every 200 miles). It was my fault that I never knew of the SECRET warranty. I should have known about the SECRET warranty, that GM never informed me about. I guess that GM has never made an engineering error or admitted that they did, when they did.

Rock36

So why did the Ferrari 308 have an issue with broken sodium-filled exhaust valves, yet Ferrari used sodium-filled valves successfully in other cars since?

For all your appeals to logic, I find it funny that you would reason that because a sodium exhaust valve worked for one car, that it would automatically work in another without a complete understanding of the failures (which none of us have).

MTIRC6Z

WOW Mark, you must live in a VERY upscale neighbourhood...where I come from a head job can be had for as little as 50 bucks.

Cheers, Paul.

Dirty Howie

Joe

Thanks for affirming what I was trying to say to Mark in my previous post. Corvair, Vega, I'm sure there are plenty of other examples of the infallible GM engineers


DH

Dirty Howie

Some times you have to take your head out of the Logic 101 manefesto, smell the coffe and use common sense when addressing this issue


DH

MyLS1Hauls

MY point wasn't that because it worked in the LS6, it will work in the LS7. MY point was that GM found the weight reduction necessary for the LS6, LS7, and new LT1. The LS2 and LS3 were skipped, due to cam differences. If they felt that the LS7 could get by with a cheaper SS valve, they would have used it.

On a side note, a while back, when the 450cc 4 stroke dirt bikes became popular, Honda had a problem with the Ti valves breaking heads off. The aftermarket's answer: solid SS valves and stiffer springs. They appeared to work, but guys argued about it...Some went with better Ti valves, and some went with SS valves. It was proven that the SS valves weren't as stable near the 12k rpm redline, but people continued/continue to use them. Mostly without incident. You do see some mysterious broken valve springs, which some attribute to valve float/bounce. But we all know that valve bounce is just an internet phenomenon

MyLS1Hauls

MY point wasn't that because it worked in the LS6, it will work in the LS7. MY point was that GM found the weight reduction necessary for the LS6, LS7, and new LT1. The LS2 and LS3 were skipped, due to cam differences. If they felt that the LS7 could get by with a cheaper SS valve, they would have used it.

A while back, when the 450/250cc 4 stroke dirt bikes became popular, Honda had a problem with the Ti valves breaking heads off. The aftermarket's answer: solid SS valves and stiffer springs. They worked, and guys argued about it...Some went with better Ti valves, and some went with SS valves. It was proven that the SS valves weren't as stable near the 12k rpm redline, but people continued to use them. Mostly without incident. You do see some mysterious broken valve springs, which some attribute to valve float/bounce. But we all know that valve bounce is just an internet phenomenon

MTIRC6Z

Yep and I figure they're all rolling over in their graves right now thanking their lucky starts they don't have to take the blame from you guys for this perceived fiasco.

I say "perceived fiasco" because there are probably about 29,000 Z06s running around that haven't failed??? IMHO the engineers have nothing to be blamed for here because there are Z06s with 100,000-200,000 miles running failure free. An execution/QC issue should not be blamed on the engineers. For sure you can blame GM at large, just not the engineers specifically as a group.

Cheers, Paul.

Mark2009

Appealing to logic only works when all the parties involved understand what logic is and will acknowledge it when they see it. When that criteria is not met then it is simpler and quicker to just give short definitive answers, even if they may not be correct in 100% of the situations. Otherwise the nit picking nature of the discussion continues ad infinitum. "What if" is not a valid form of argument, unless perhaps conducting some type of differential diagnosis.

The 2V Ferrari owners never did, as far as I could determine, research the nature of their failures, nor try to replace the valves with new OEM units... they just rushed to the solid valve replacement. I saw at least one photo of several valves in which corrosion appeared to be present at the break point(s), leading me to wonder about the possibility of the sodium mixture attacking the steel alloy of those valve stems (see http://www.cip.ukcentre.com/rust2.htm ).

As to understanding our failures, given GM's experience with these valves -- most of it successful (in the LS6) -- it is highly unlikely that they would have selected a valve that is unable to do the job to the point that it needs to be replaced with a totally different design. It just doesn't make.... common sense

Mark2009

Well keep in mind that if you're arguing from the end point -- that is, if you've already decided what the problem is (wrong valve) then the blame must be placed on the people that selected that valve. If the engineers cannot be proven wrong, or at least claimed wrong, then replacement of the valve with a different design cannot be claimed to be so right.

In other words if one admits that the engineers may not have made an error in valve selection, then one cannot claim that the wrong valve has been used in order to champion use of a different type of valve.

Therefore if it is one's position that the wrong valve has been used, then the engineers must be wrong. The verdict has preceeded the trial

From an old Paul Newman movie, Judge Roy Bean:

Dirty Howie

Paul

My point to Mark was that any engineer or group of them can make mistakes, screw up calculations or just not see the trees for the forest. Do you remember the fiasco with the Hubble telescope? Certainly NASA's engineers are as educated as GM's ..... right?

I do blame GM. They are ultimitely responsible for the engineers, manufactures and quality control implementation. I'm not clear how you can be so certain that the engineers are not at least partially to blame.


DH

'06 Quicksilver Z06

The concern is not only in, nor limited to, GM's selection of the valves that they decided upon.

With the repeated failures, and the current acknowledgment by GM, that there was a machining issue with the guides, or a QC issue, there is equal concern, among some, that a similar situation may also exist with some of the valves as well.

Especially in the wake of the discovery of a random one to be grossly inconsistent in it's wall thickness.

In this day and age of modern manufacturing, a valve like that, should not have wound up in somebody's car. But it in fact did.

CanadaGrant

Here's the way I look at it Howie. If GM says it's a quality control problem, they only have to fix the Z06's that actually fail, are still on warranty and unmodified. If GM says it's an engineering mistake, they have to replace the heads on every Z06 out there......