My car shut down tonight and would not start. There was no spark so I looked a little deeper and found out the water pump gear was not spinning. Tore the timing cover off and saw a broken timing chain. Every tooth was gone on the crank shaft gear.
I'am worried about having valve damage from this. I was at maybe 6000rpm when it happened. I tried to start it a couple times thinking it was maybe a loose wire causing no spark.
Is my engine screwed now. What is still good and what is crap.
How do I get that gear off the crank and will I be able to change the gear set and have it run again.

 

Could be just the gear. Something could have broke and bind the engine causing that damage. Maybe internal.

 

If it's just the chain and gear, you'll need new ones of those as well as new valves.

 

I would recommend the engine be completely torn down. There is probably metal all through it. Valve damage is a definite possibility.

 

I just spoke with the guy who built the engine and he said there will be valve damage for sure. He told me to ship the heads to him and he will send me them back fixed with a timing set and what ever else is needed to fix the engine. I'm very happy to hear he is standing behind his motor. To bad its such a pain to pull the engine.

 

Has anyone seen every tooth stripped off the crank gear before. I guessing the chain broke then got caught in the bottom of the timing cover and killed the lower gear. I'm surprized it did not wreck the timing cover. Now I can fix my little oil pan gasket leak

 

Holy hell that sounds like some carnage! Take pictures!

 

I'll try a get some photos posted when I figure out how to do that. I pulled the engine and tranny and tore off the heads today. 5 valves on one head and 4 on the other are bent . I'm sending out the heads tomorrow but I'm not sure if I should leave the bottom end or open her up. Everything turns over nice and all the piston go to the top of each cyclinder. The cam moves fine and the oil pump still pumps oil. I'm going to take the pan off and redo the pan gasket because of a leaky gasket.

 

Well, since it's almost winter in beautiful Ontario, you might as well pull it apart and be sure it's debris free as Shoebox suggests....

 

There's related thread by OP on this topic.

https://www.camaroz28.com/forums/sho...d.php?t=707087

 

I was looking at my gear set and it says on the gear GM PPM . Does that mean its a GM Performance Part gear set. I've been doing searchs on this problem and found that there have been alot of Extreme duty timing set failures. It almost seems like more ED failures then stock timing sets.
Injuneer what set do you think I should get.
I don't have the money now to redo the bottom end and that means no more driving this year.

 

I've been turning the LT4 ED set to 7,000+RPM for 9 years at this point, driving a solid roller cam with some pretty healthy spring pressures, and it hasn't failed. I did have the shop cut lightening holes in the excessively heavy "solid" cam sprocket though.

 

I'm going to remove the W/P drive should I also remove the gear behind the cam gear that drives it?.
How much was the LT4 ED set

 

When I bought it about 10 years ago, I'd say about $245. Probably a lot more than that now. And I run a stock gear-driven water pump.

 

Could my harmonic balancer have anything to do with the chain breaking. I don't want to put this back together and have it come apart again.