I've paid close attention to Norton rod breakage reports to find they only break AFTER something else lets go first. I've read a couple reports of 920 engines breaking them near top end but may have missed what let go first. TC's 150 hp 8000+ rpm dragster engines did 160 runs on factory rods and parts. I would have factory rod in Peel's blown 920 but for two reasons, one these rod survived/endured over 11,000 rpm, so a few orders of piston jerk and crank flex loads way over their designed use but mainly because Jim's lighter pistons gave better/lower CR than the Coswell pistons and JIm's kit came with special piston pins in the Carillo rods which are lighter than factory rods. Peel's crank had already been dynamic balanced for the factory rods just before Jim's new kit came out. I'm more pensive on the rod bolts capacity weakness than factory rods. Norton rods are over built enough they don't experience the Al fatigue failure unless being run way harder-faster than any street-able engine I've ever heard of. Norton rods are not power/torque/time limited only HI RPM piston jerk down acceleration G force SPIKE limited but still ain't found that limit before crank, cases and alternator and oil pump/cam drive bend, crack or come apart first. M.A.P. Cycles in Fla. was the first I saw with all Al rods and caps that look like the Al example shown above. Just need to grind cases a bit to clear the bigger size Al end caps. Don't know what that does to crank BF except it should lower it some d/t being a bit lighter near the counter weight area.
