This happened Saturday night in the burn out box. Bent 6 exhaust valves and 2 intakes. Guess I will stay home and work on it.
I was using stock factory bolts. Never had a problem before. One of the bolts fell out, maybe I got distracted and forgot to thread lock that bolt ? I never have liked that the bolts don't fit tight in the gear. Might try some shouldered ARP bolts and cut them to length. I like the four bolt idea, gonna look into that. Thanks for the idea !
Almost certainly the bolts loosened up.. one fell out, the ensuing motion and twisting of the loose gear broke the other one. I, and many other folks, have run that setup with 800+ lbs roller cam springs, and never broken those bolts, it's not a concern that I am aware of. Although I do not use the stock bolts.. TA has some nice ARP crank gear bolts.- although I often use a couple of their oil pan bolts, I have had a few around from left over/unused TA/ ARP oil pan bolt kits over the years. They work great.. JW
Jim, No doubt the one bolt loosened up. I don't even see thread locker in the cam. Ugh.. I am definitely going to upgrade the bolts. Thank you for your input.
Instead of doing a shoulder bolt a bushing could be inserted in the gear to snug it up, just another idea to improve it
All back together and running again ! Took a new set of valves and timing set. I did notice that both bolt holes in the old cam gear measured .365 in diameter. The new cam gear had one hole that was .365 and the other is .320. So there was hardly any rotational movement of the gear on the cam. I did go ahead and pin the gear to the cam with a 1/4 in. steel pin. Can't wait to get back to the track this weekend !
I lost a cam gear in Salem in 05 almost the same result. I added the two bolts and wired them . ain't comin off again! lol