Z06 Production

[halp]

Is there any way to find out how many Z06s were produced in each month for the 2002 and 2003 year build? The reason i am asking is that it appears that these cars may experience valve spring failures and data compiled on another site seems to indicate that vehicles manufactured during a specific period may be more susceptible to failures. Unfortunately the data assumes that the same amount of Z06s were made every month during the build year. This may not be the case as info on the C5 Registry site shows that more z06s were produced in the second half of 2002 than the first half and more z06s were produced in the first half of 2003 than the second half. By finding out how many were produced by month during 02 and 03 this problem may not be as bad as some think it is.

 

[LT4man]

The Z06 which they are talking about is the C6Z.

I believe the LS6 engine in your C5 has not encountered any problems whatsoever.

 

[Hib Halverson]

I've not heard of the LS6 having problems with valve spring breakage.

At what other site are you reading this?

 

[halp]

I've not heard of the LS6 having problems with valve spring breakage.

At what other site are you reading this?

This is written up on the Corvette Forum. Here is the link to the analysis done by one of the members.

***Build Date/VIN Analysis of LS6 Valve Spring Failures*** - Corvette Forum

 

[Hib Halverson]

This is written up on the Corvette Forum. Here is the link to the analysis done by one of the members.

***Build Date/VIN Analysis of LS6 Valve Spring Failures*** - Corvette Forum

Unless your engine is modified or high mileage, i wouldn't worry.

I read that thread with interest and I appreciated the work in gathering the information, but I'm questioning some of the data.

If the issue here is "defective" valve springs, then for this data to be credible, the person compiling it should have refused to consider any spring failures on engines which have been modified with:

1) Calibration with a rev limiter which has been set higher than stock
2) Camshafts having more duration or higher lift.
3) Rocker arms with higher ratios.

Also, he shouldn't consider engines in cars which have been raced frequently in cycles where the engine is often above 5000 rpm or have engine mileages over 60,000.

My guess is if those rules were applied the amount of failures is going to be significantly less.

 

[halp]

I agree with your comments and when you look at the data most of those who reported mileage show that more failures were at higher mileage. Unfortunately many did not report mileage. My biggest problem is that the data he presents seems to show that build date for 2002 and 2003 makes a big difference on whether or not a spring will fail. He assumes that the same amount of Z06s were made each month during the build. He also assumes that members of the forum have Z06s across the entire build. I just feel that it is tough to make a statement based on 80 vehicles out of over 16000 built in 2002 & 2003.
Thanks for your input, I would still like to find out build per month of Z06s during 2002 & 2003.

 

[Hib Halverson]

I do not have any month-by-month build numbers for that span of dates but I will suggest you consider one of the comments made in that forum on the CF and that is that, because 02 and 03 were the highest production years for Z06, it follows that the greatest amounts of failures might occur in those years.

One place you may find such build numbers is the C5/C6 Registry web site.

My guess is that, as long as your valvetrain is not modified, you are not regularly taking your car to track day events and your car has less than 75,000 miles on it, you have little or nothing to worry about.

 

[halp]

That was my post on the other forum that many more Z06s were built in 02 and 03. I tried the C5 registry and best I could find was first and second half of year builds for Z06s. Again that info showed that more Z06s were built in the second half of 02 and the first half of 03 than in the first half of 02 and last half of 03. It is hard for me to believe that with info from 131 owners out of 16,932 Z06s built in 02 & 03 that you can conclude that everyone should replace their valve springs.

 

[DukeOfEarl]

Hi Halp

Halp I was talking to Corvette Central. I had a question on my 2003 Z06.
I asked how many came out with the special red and black interior they told me 1600 that year

Also this may help. The one I got has a new engine 383 stroker. Read the story on the problem of the zo6.


This is the story of how this 2003 50th anniversary Z06 Corvette became what it is today its life started as any other Z06 in Bowling Green Kentucky in a cold January morning in 2003 its life began with the LS6 405 horsepower heart that was to beat strong throughout its amazing life it had other STRONG qualities added to it like Z51 suspension for roller coaster like grip, larger brakes to bleed off the speed generated by the strong LS6 that exhaled through the ultra-light titanium exhaust, it was special because of the options it had installed, bose sound system, heads up display so the owners focus was on the road with the ability to monitor that beastly LS6. LIFE WAS GOOD for our Z06 UNTIL…. It was traded in to a dealer who took it in, now this dealer he did all the normal stuff he detailed & serviced it then proudly put it on his front line FOR SALE well the beastly LS6 was awesome, however it did have a fatal flaw the valves where lightened to help achieve the 405hp, what the engineers didn’t take into account was the valves would break if pushed, not a good trait in a car that was built to do just that, be pushed. One day the Z06 caught the eye of a customer who wanted to take it for a test drive; the salesman happily retrieved the key & off the two of them went the customer gingerly pulled off the sale lot & thought WOW this is great & at first he drove it like anyone with any amount of respect for someone else’s car would, but then, the devil inside said push it you know you want to & he GAVE IN, 1st gear OH MY GOD this thing is FAST 2nd GEAR wait… what was that oh crap all hell broke loose the customer missed 2nd gear & pushed the Ls6 to its limit & the fatal flaw couldn’t hang on the ls6’s life was over. To FIND OUT how the STORY ENDS GO TO Used Cars Tampa Florida 33619 Used Car Dealer Plant City Saint Petersburg - Superior Autos for You CONTINUED from AUTOTRADER… Now some will be turned off by this & would never buy a corvette with a blown engine & that’s fine, but there was this guy in Tampa FL named Jon Hardy (to find out more about Jon read “about US”), Jon owns Superior Autos for You, & Jon saw the potential just waiting to be unleashed the first thing was to see how bad it really was & man was it ugly the engine was destroyed but that’s what he expected so the hunt was on for a replacement, but stock wasn’t going to do Jon called this shop then that shop he read forum after forum then he found Texas-speed Jon & the rep talked for hours because Jon wanted to be sure before he dropped that kind of coin of what he was getting the decision was made he would put a FORGED 383 STOKER with a forged Lunati crank, forged Lunati H-beam rods, forged wiseco -3 pistons then have it balanced & blue printed to back up his claim, other power adders include a Power Bond 25% under driven harmonic balancer, cloyes billet true roller timing chain, spinning a custom grind COMP camshaft, pushing LS7 lifters, to open MANLEY Stainless steel valves ( to fix the FATAL FLAW), ARP bolts holding down the 243 Cathedral port heads, keep the valves closed are Precision Race Springs, breathing through a VARAM cold air intake, out of a set of TEXAS –SPEED long tube Stainless steel headers & catted x-pipe through the factory Titanium Exhaust just to screw with people, they flow great & are lighter than ANY aftermarket exhaust. All these parts come together & work in perfect harmony with a FASTERPROMS tune by Jeremy Formato to lay down 450 REAR WHEEL HP!!!

 

[DukeOfEarl]

valve spring

Is there any way to find out how many Z06s were produced in each month for the 2002 and 2003 year build? The reason i am asking is that it appears that these cars may experience valve spring failures and data compiled on another site seems to indicate that vehicles manufactured during a specific period may be more susceptible to failures. Unfortunately the data assumes that the same amount of Z06s were made every month during the build year. This may not be the case as info on the C5 Registry site shows that more z06s were produced in the second half of 2002 than the first half and more z06s were produced in the first half of 2003 than the second half. By finding out how many were produced by month during 02 and 03 this problem may not be as bad as some think it is.

They did have problems with some of the Z06 here is the story of the one I bought and the new engine.
Note that this guy builds high end cars and engines.
This is the story of how this 2003 50th anniversary Z06 Corvette became what it is today its life started as any other Z06 in Bowling Green Kentucky in a cold January morning in 2003 its life began with the LS6 405 horsepower heart that was to beat strong throughout its amazing life it had other STRONG qualities added to it like Z51 suspension for roller coaster like grip, larger brakes to bleed off the speed generated by the strong LS6 that exhaled through the ultra-light titanium exhaust, it was special because of the options it had installed, bose sound system, heads up display so the owners focus was on the road with the ability to monitor that beastly LS6. LIFE WAS GOOD for our Z06 UNTIL…. It was traded in to a dealer who took it in, now this dealer he did all the normal stuff he detailed & serviced it then proudly put it on his front line FOR SALE well the beastly LS6 was awesome, however it did have a fatal flaw the valves where lightened to help achieve the 405hp, what the engineers didn’t take into account was the valves would break if pushed, not a good trait in a car that was built to do just that, be pushed. One day the Z06 caught the eye of a customer who wanted to take it for a test drive; the salesman happily retrieved the key & off the two of them went the customer gingerly pulled off the sale lot & thought WOW this is great & at first he drove it like anyone with any amount of respect for someone else’s car would, but then, the devil inside said push it you know you want to & he GAVE IN, 1st gear OH MY GOD this thing is FAST 2nd GEAR wait… what was that oh crap all hell broke loose the customer missed 2nd gear & pushed the Ls6 to its limit & the fatal flaw couldn’t hang on the ls6’s life was over. To FIND OUT how the STORY ENDS GO TO Used Cars Tampa Florida 33619 Used Car Dealer Plant City Saint Petersburg - Superior Autos for You CONTINUED from AUTOTRADER… Now some will be turned off by this & would never buy a corvette with a blown engine & that’s fine, but there was this guy in Tampa FL named Jon Hardy (to find out more about Jon read “about US”), Jon owns Superior Autos for You, & Jon saw the potential just waiting to be unleashed the first thing was to see how bad it really was & man was it ugly the engine was destroyed but that’s what he expected so the hunt was on for a replacement, but stock wasn’t going to do Jon called this shop then that shop he read forum after forum then he found Texas-speed Jon & the rep talked for hours because Jon wanted to be sure before he dropped that kind of coin of what he was getting the decision was made he would put a FORGED 383 STOKER with a forged Lunati crank, forged Lunati H-beam rods, forged wiseco -3 pistons then have it balanced & blue printed to back up his claim, other power adders include a Power Bond 25% under driven harmonic balancer, cloyes billet true roller timing chain, spinning a custom grind COMP camshaft, pushing LS7 lifters, to open MANLEY Stainless steel valves ( to fix the FATAL FLAW), ARP bolts holding down the 243 Cathedral port heads, keep the valves closed are Precision Race Springs, breathing through a VARAM cold air intake, out of a set of TEXAS –SPEED long tube Stainless steel headers & catted x-pipe through the factory Titanium Exhaust just to screw with people, they flow great & are lighter than ANY aftermarket exhaust. All these parts come together & work in perfect harmony with a FASTERPROMS tune by Jeremy Formato to lay down 450 REAR WHEEL HP!!!