601 chevy in V drive. Timing chain broke. (At the time around 3000rpm). Shows a lot of signs of stress and cracking in various links. Has a total of maybe 25 runs on it. Cloyes 3510 billet. Chain says Japan. I tore it down and besides the valves it bent at failure I can find no apparent cause. Cam end play .010. Brodix BB3 Xtra heads. 2.350 stainless valves. PAC 1247 triple springs 835 lbs.open. Installed height 1.970. 2.350 stainless valves. .440 lobe lift, 1.7 T&D shaft rockers. .746 gross valve lift .120 wall pushrods, red zone lifters. Found no indication of coil bind. No lifter damage. No valve to piston contact except for damage after chain break. Roller to lash cap pattern centered maybe 1/16 wide pattern Cam, distributor, and oil pump turns fine. Magnaflow water pump turns. No bent pushrods. Was told possible stainless heavy valves and spring pressure but I don't know? I plan on going back with a Jesel belt but not finding an apparent cause has me a little worried. I will bite the bullet on titanium valves if need be. Anything I might be overlooking? Turns 7200. Thanks, Galen
Years ago I replaced the timing set in my Pontiac Formula.
Ran good for a few days.
Chain came apart.
Found it is was made without having the masterlink lock(s) put into place.
When I returned to the parts store I was told that the guys behind the counter see them like that quite often.
I was pretty upset to hear them say that after the fact.
Just an idea after reading your description...
Any chance it could have been an undersized set for a block that had been line honed? Maybe if the set was unusually tight and with that kind of spring pressure and a poor chain those all could combine to have that problem? Just taking a wild guess.