What causes this?

[3100 MPFI]

a few weeks ago, I met up with tiajuana_no, and since I had my camera, I took some pics.

this is from his blown engine (he swapped it out already), but he and I are both curious as you what can cause this.

[StEvEzAsYcHo]

I dont know for certain.. I always attributed it to ignoring the timing belt.. Becasue if you go 60,001 miles without changing it, it seems the belt starts to fail.. But again, I am not 100% certain..

[SappySE107]

Bad tensioner or bearings in the pullies is my guess.

[Rhedalert]

yeah looks like the side of the belt was riding hard against something, maybe from a pulley kicking outwards. How does the timing belt cover look?

[3100 MPFI]

cover was not on the engine. Maybe when Tijuana_no gets back in, he can fill in more details.