This is the first time I have heard of a stock ls1/ls6 that let a timing chain go. In your case, if your buddy gets a new LS6 have him get a heavy duty timing chain.

 

Ya, it's kinda strange that the same thing happend to both motors. :huh: I saw one of the plugs that came out of the engine. It was hamburger. It must be a real mess inside. Only thing he says that has been done to it is LS1 edit and headers. So he says. We may suspect Nos?? I haven't seen the car. He only gets one chance for a over the counter parts warranty. Next time it has to come into the dealer. Then we'll see. :secret:

 

Something is wrong with the car if he is breaking timing chains. I know of H/C cars that have run the stock chain with no issues. I would guess that something may be wrong with the gears (Cam or Crank) in there that is causing the problem. Maybe one is out of round, has a damaged tooth, or is just not secured properly. It does sound like he should upgrade to a double roller timing chain in the future. They are only ~$100-150.

 

It's never been a huge issue but they have switched to a beefier timing chain...late year 04' Z06's strated getting the LS2 timing chain, and they're switching to the LS2 chain for all LSX series timing chains. It noticeably more heavy-duty and costs $30. And you don't have to mess with setting a double chain set properly.