"I paid THIS MUCH!!" Okay.... 
C8 30 Miles Broken Valve Spring Pic
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 35,010
Likes: 12,396
From: NE South Carolina
GM's been making the small block engines with the same bore spacing as the LT2 since a year before my '56 Chevy V8! Been using those beehive valve springs for years. Looks like those C8s found with issues occurred shortly after purchase. Obviously a defect not caught by the valve spring manufacturer.Sure they have pushed the LT2 to get 495 hp with no doubt faster valve opening and closeting rates. More stress on the springs. Broke my C8 in as recommended, limiting rpm and just reached 500 miles. Did two 0 to 60 runs (without the launch mode) and shifted at 6000 rpms. No valve spring issues!
Unlike defects in most C8 valve springs!
Last edited by JerryU; Sep 26, 2020 at 08:19 AM.
Instructor
Joined: Jun 2020
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From: Greensburg, PA
Sorry, but that's just a ridiculous statement. That's why warranties exist...because manufacturers are fully aware there will be issues. That's why Porsche, Lamborghini and every other brand have service departments. Last time I checked, they are all still all man made.
Thread Starter
Safety Car
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you are correct,but emotion wins over fact every time.
Le Mans Master
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Originally Posted by lordofwar
car was fixed.owner told them he did not want the car,did not trust it,should NEVER happen to a new $75k car and he is correct.he told dealer he does not want the car.he said they are buying it back for full price what he paid for it.
wish him well.
wish him well.
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Le Mans Master
Joined: Aug 2000
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From: Austin Texas
My guess is that we we finally KNOW what happened, it will be traced back to the Covid shutdown and a batch or 2 of these springs were not properly heat-treated, and it will have had to do with shutting of the spring manufacture down and then bringing the factory back into working order.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 35,010
Likes: 12,396
From: NE South Carolina
^^^
"My pure "guess" from the one pic we have and the break - it could a defect in the rod that made the wire! Fact is GM is not going to tell us what the actual problem is!
Would expect IF it's heat treatment they would check a sample from each heat treated batch. Easy to do as with any spring check you measure the force required to press to open and the closed valve seat force at that compressed distance. Has to be a fairly tight spec.
Not properly heated or tempered it would be too strong or too week. Easy check. The whole batch would be similar. If it's an internal defect, like a non metallic inclusion, that would be in only few and harder to sample check. It fact if every spring was checked autonomically for valve open and closed distance force, a defect would not necessarily be caught. Lets see 30 miles at 2000 average rpm and one opening every other revolution --- won't bother to calculate average speed, tire diameter and gear ratio to get a number of valve openings before failure- but it's a lot!
"My pure "guess" from the one pic we have and the break - it could a defect in the rod that made the wire! Fact is GM is not going to tell us what the actual problem is!
Would expect IF it's heat treatment they would check a sample from each heat treated batch. Easy to do as with any spring check you measure the force required to press to open and the closed valve seat force at that compressed distance. Has to be a fairly tight spec.
Not properly heated or tempered it would be too strong or too week. Easy check. The whole batch would be similar. If it's an internal defect, like a non metallic inclusion, that would be in only few and harder to sample check. It fact if every spring was checked autonomically for valve open and closed distance force, a defect would not necessarily be caught. Lets see 30 miles at 2000 average rpm and one opening every other revolution --- won't bother to calculate average speed, tire diameter and gear ratio to get a number of valve openings before failure- but it's a lot!
Last edited by JerryU; Sep 28, 2020 at 02:55 PM.
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When you can pay 90K with all the options taxes, fees, etc - you deserve better quality control and engineering than GM has shown with this car- this is just one of many engineering failures and lack of quality control, and the worst rollout of any highly anticipated car in history. The UAW line workers have shown they do not care about the quality of the fit and finish of the product they put out, and the jobbers seem to be producing an awful lot of inferior parts. There is a reason long time Covette owners like myself who have owned lots of new Corvettes, would never consider buying the first year models of a new generation-they always have a lot of bugs that takes years to straighten out- and then just when they get a fairly reliable car-they come out with a new generation and the whole cycle starts over again. GM if it wanted to- due to its size, engineering capabilities, and long history in the car business -could build better cars than Lexus, Porsche, and BMW-but they do not, and never have. They have already switched the majority of Corvette engineers to the all electric versions of their cars- as they see that as the future of GM.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
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From: NE South Carolina
.....There is a reason long time Covette owners like myself who have owned lots of new Corvettes, would never consider buying the first year models of a new generation-they always have a lot of bugs that takes years to straighten out- and then just when they get a fairly reliable car-they come out with a new generation and the whole cycle starts over again. ....
Fact is I bought an eastly 2014 C7 Z51. It was built September 2013. It was back at the dealer for service once in the 3 1/2 years I had it. That was because GM sent a notification to have the dif fluid check for level. I watched as the Corvette tech (who just came back from C7 Training) check. It was fine. Never went back as have done all my oil/filter changes on all 5 prior Vettes and may my C8.
So your opinion and statement you would never buy one are confusing.
Last edited by JerryU; Sep 28, 2020 at 04:48 PM.
Racer
Joined: Feb 2000
Posts: 322
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From: Sin City
That was 55 years ago! I have a 67 BB that is worth MANY times the 70k of this car.
I just bought a 2020 GMC Denali DRW Duramax(Isuzu) that cost quite a bit more than this car and it broke 20 miles outside the store. Crap happens.
I just bought a 2020 GMC Denali DRW Duramax(Isuzu) that cost quite a bit more than this car and it broke 20 miles outside the store. Crap happens.
Safety Car
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From: Philadelphia PA
Safety Car
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From: Norman OK
The owner is an idiot then. GM has absolutely zero control over the QC of the valve springs, that falls on the spring manufacture. The springs are sent to the engine plant, then installed in the engines and then sent on their way to plant to be installed in the vehicles.
Good luck to the owner, that C8 will be put back on the lot, sold to the next owner with a mark up as well. The only thing different I would ask for is that every valve spring is replaced instead of only replacing the affected cylinders.
Thread Starter
Safety Car
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The owner is an idiot then. GM has absolutely zero control over the QC of the valve springs, that falls on the spring manufacture. The springs are sent to the engine plant, then installed in the engines and then sent on their way to plant to be installed in the vehicles.
Good luck to the owner, that C8 will be put back on the lot, sold to the next owner with a mark up as well. The only thing different I would ask for is that every valve spring is replaced instead of only replacing the affected cylinders.
Good luck to the owner, that C8 will be put back on the lot, sold to the next owner with a mark up as well. The only thing different I would ask for is that every valve spring is replaced instead of only replacing the affected cylinders.
Last edited by lordofwar; Sep 29, 2020 at 08:10 PM.
Safety Car
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From: Norman OK
And I will still stand by my comment, no commando though as I dont like how it feels when there are no underware.
To answer your question, yep have owned several 1st year vehicles. I worked for GM for 3 years in an assembly plant as well, my Dad worked for and retired from GM with 30 years of service as the head over the plant maintenance teams. So I have some pretty good knowledge on GM, GM manufacturing processes and the woa's of dealing with a 1st run 1 model year car. To get all pissy about a broken valve spring and demand a buyback and or replacement is a little extreme. Its a machine, with thousands of parts that hundreds of people have touched in order to put it together. There absolutely no way to test every part for QC, hence why the Feds require cars to have a 3 year / 36k mile warranty to cover things like this.
That owner got all hurt and upset over something that could have been resolved in a couple of days once the parts were in stock. I would suggest maybe that person go buy one of the hand built exotic cars if they demand a high degree of QC so they can sleep at night knowing their car will never break down, then have them report back and let us know how the exotic world is compared to the Domestic sports car market.
Thread Starter
Safety Car
Joined: Nov 2011
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And I will still stand by my comment, no commando though as I dont like how it feels when there are no underware.
To answer your question, yep have owned several 1st year vehicles. I worked for GM for 3 years in an assembly plant as well, my Dad worked for and retired from GM with 30 years of service as the head over the plant maintenance teams. So I have some pretty good knowledge on GM, GM manufacturing processes and the woa's of dealing with a 1st run 1 model year car. To get all pissy about a broken valve spring and demand a buyback and or replacement is a little extreme. Its a machine, with thousands of parts that hundreds of people have touched in order to put it together. There absolutely no way to test every part for QC, hence why the Feds require cars to have a 3 year / 36k mile warranty to cover things like this.
That owner got all hurt and upset over something that could have been resolved in a couple of days once the parts were in stock. I would suggest maybe that person go buy one of the hand built exotic cars if they demand a high degree of QC so they can sleep at night knowing their car will never break down, then have them report back and let us know how the exotic world is compared to the Domestic sports car market.
To answer your question, yep have owned several 1st year vehicles. I worked for GM for 3 years in an assembly plant as well, my Dad worked for and retired from GM with 30 years of service as the head over the plant maintenance teams. So I have some pretty good knowledge on GM, GM manufacturing processes and the woa's of dealing with a 1st run 1 model year car. To get all pissy about a broken valve spring and demand a buyback and or replacement is a little extreme. Its a machine, with thousands of parts that hundreds of people have touched in order to put it together. There absolutely no way to test every part for QC, hence why the Feds require cars to have a 3 year / 36k mile warranty to cover things like this.
That owner got all hurt and upset over something that could have been resolved in a couple of days once the parts were in stock. I would suggest maybe that person go buy one of the hand built exotic cars if they demand a high degree of QC so they can sleep at night knowing their car will never break down, then have them report back and let us know how the exotic world is compared to the Domestic sports car market.
all you had to do was say what you just said without calling him a idiot.the rest of your statements are true.as you know emotion wins over fact every time,human nature,
Team Owner
Joined: May 1999
Posts: 34,551
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From: Auburn Hills MI
If it is a non-interference motor who cares.
I had one of the first LS1's with an aftermarket cam, it broke springs left and right until we put a rev kit in it. I could do the entire motor in under an hour I did it so many times.
I had one of the first LS1's with an aftermarket cam, it broke springs left and right until we put a rev kit in it. I could do the entire motor in under an hour I did it so many times.