Two hours on a 4 bolt 468", steel crank, HD I beam rods with ARP bolts, Kieth black 9.5:1 pistons. Seemed to lock up so we pulled it down and THREE rod bolts had loosened up. #8 was bad enough to allow the cap to lift and the bearing to spin.
I guess a stretch gauge is in my future.. I have always just torqued to spec and never had a problem. Anybody else have this happen? It sure didn't take long, and it happened when the motor was idling. The good news is the cam broke in fine and everything else looks perfect. I guess I pull it apart, grind the crank, and put it all back together. Just sucks to have a brand new piece do this, but I guess it could have been much much worse. I always heard guys talking about the stretch gauge being the only way to go and I guess now I'm a believer too..... River Dad