[PAUL K]

Curious what issues or success stories folks have had with factory cast crankshafts.

I've seen one break in two pieces. It was the later style crankshaft that was in a 76 455 four speed Trans Am that I doubt was making 300 horsepower. The outer ring on the harmonic damper had slid back towards the timing cover and was rubbing against it. Generally, the car seemed like it had seen a lot of harsh driving. I figured the damper becoming non-functional and one too many power shifts led to the crankshafts demise. The engine was still running but made a bunch of noise and shook a lot. This was the only factory crankshaft failure we have seen first hand.

Attached is a video show casing that crankshaft

https://fb.watch/h-fC5Pks-W/


On the other hand, we have been successful using factory crankshafts. We've made close to 1100 horsepower using nitrous oxide. We've built belt driven (8-71) supercharged engines that have seen many years of service in the 800-900 horsepower levels. We've routinely shifted them over 7,000 rpm, buzzed them through the traps as high as 7600 and they have held up without any issues what so ever.

I'd like to hear other folks experiences.... good or bad?