The damper you used was barely acceptable to begin with. After X number of miles it was junk.
That crank did NOT fail and I don’t care who says what. There isn’t a pinch of **** difference between all those China forged cranks.
You are seeing exactly what I’ve been bitching about since ATI tried to jam one of their one size fits all but doesn’t fit anything worth a **** dampers up my ***.
Any and by any I mean ANY elastomer damper has a very narrow tuning range and it starts to degrade they day it’s made. The degradation continues on apace and exponentially until some failure happens.
Not many understand the Pro teams using the ATI damper pay engineers to change the tune of the damper on a constant basis. And they run the engines in a relatively narrow RPM range. Plus they rebuild them on a regular basis as part of routine maintenance.
You had a damper failure that killed your crank. It’s a damned shame the crank is getting blamed for a failur caused by a piece of crap damper.
The ONLY thing the ATI damper has going for it is you can tune and rebuild it. Of course, you need a PhD level engineer to do it.
The rest of the vulcanized rubber dampers are a complete waste of money.