I also don't think it's the springs, unless they were binding causing the lifter to bottom out putting too much force on the cam.

Any pics of the cam? How many lobes are damaged?

 

Looks like the bolts backed out. Look at the bolt laying there in the pic its not snapped off the thickness of the cam gear. Plus the cam gear has what looks like oblonged holes from the bolts hitting.

 

Looks snapped off to me, he even said all three bolts and the dowel pin were snapped off. The cam definitely seized and the crank kept going and sheared off the bolts. I'm impressed the chain didn't break.

 

Where did you say you bought that chain from again?? Im buying one..

 

Maybe I wasn't clear enough. Look at the length of the bolt. Had the cam stopped and the cam gear kept rotating the bolts would have sheared at the front of the camshaft. From the pic I have to work with the bolt is much to long for that.

 

Yea it looks like the bolt backed off and the tip was snapped off...also notice the lack of threadlocker on the bolt.

OP, did you use threadlocker when you installed those bolts?

 

The sprocket hub is around 0.56" thick. That's 11.4 threads not used at 1.25mm pitch. I see roughly that many threads on the rest of the bolt.

Even if the bolt backed out, there is nothing on the inside of the timing cover that I know of for it to catch on. And he would have heard it scraping the cover as it was backing out. A pic of the inside of the cover and of the bolt heads would help. The cam bolts are quite long, no surprise there won't be visible thread locker, unless you put thread locker on the entire length of the bolt. I usually just put a couple drops on the first few threads. Also I don't think a bolt backing out would cause lifter damage. He said 5 lifters were messed up.

Alas, we need some more pictures!

 

Those 3 bolts and a dowel pin would require a tremendous of force to shear or break them. The cam couldn't have locked up in the bearings and done it. Only thing I could think of would be lifter turning and digging into a cam lobe?

 

I agree, it looks like the cam gear bolts were ran loose. The wear in the cam gear looks like exactly what happens when ran loose. The exact same thing happens when a wheel is ran loose, and after long enough, the heat snaps all of the wheel studs off....

Circled in red.

 

Cam wasn't hard to install at all i had the motor pulled at that time too. went in like cake.

there were a few lobes damaged on the cam pretty bad too if you ask me compared to what ive seen on other cams

got the chain from texas speed. ls2 chain supposedly. looks the same as the stock one though

yea thats kinda where i was going with it when i originally looked at it. but i did use treadlocker, the blue stuff.
Pics are coming, ive got to sell a bike today then they will come once i get back from that

but yes 5 lifters were messed up 2 which are actually in the motor cause i dont know how to pull them without messing anything up. they are the 2 closest to the front on each side. thats what i do with the threadlock also, just a drop or 2 at the end threads.
i noticed this when looking at the gear also, but im still stuck on why the lifters got stuck with the bad luck the cam did. just doesnt make sense to me.