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Not just a 10+K rev, but a violent acceleration from an unintended downshift. It bent the crap out of the crankshaft, it's certainly plausible it spit the balancer at the same time.
What did the run out measure on the crank?
 

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Was this crank checked for straightness prior to install? Also, was the rotating assembly balanced? I'm banking on neither was done on a "meticulous" build. Only 3k miles means something wasn't right at all. I'm thinking you've been looking at the effects thinking they were the causes. Sorry to hear about the hurt motor but I doubt the damper had anything to do with the failure.

I spin mine to 8k all the time with fluidamper and without. Never lost a crank bolt and never loctite it. You're in good hands with Larry now.
 

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Discussion Starter #84
i appreciate the update.
so you are certain the damper backed out as a result of the 10k rev?
I'll go with William of Occam on this one - to paraphrase - the least complex reason is usually the correct one.

What we know to be true:
1) I shifted from 3rd back into 2nd instead of 4th (by mistake) at >7500RPM which forced massive acceleration of the motor to >10,000RPM;
2) at some point that day the Fluidamper bolt head sheared off,
3) the Fluidamper came free 2-3 miles after the missed shift and took out the CAS in the process,
4) the crank was bent and No 2 rod bearing was blown rod bearing,
5) cranks are known to bend when subjected to harmonic imbalance - as in - when over-revved without a harmonic balancer.

Its hard not to see a causal relationship. However, I will be checking the torque of the balancer bold on a regular basis from here on.
 
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Discussion Starter #85
Was this crank checked for straightness prior to install? Also, was the rotating assembly balanced? I'm banking on neither was done on a "meticulous" build. Only 3k miles means something wasn't right at all. I'm thinking you've been looking at the effects thinking they were the causes. Sorry to hear about the hurt motor but I doubt the damper had anything to do with the failure.

I spin mine to 8k all the time with fluidamper and without. Never lost a crank bolt and never loctite it. You're in good hands with Larry now.
Yes, yes and the build was more than meticulous. So do I but picking up 2nd instead of 4th out of 3rd at >7500 and WOT is a whole different thing.

The motor likely went from from 5,500 to >10,000 almost instantaneously before I could get the clutch back in.
 

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0.010" whip in the middle. Couldn't even spin it freely while sitting in the block without yanking the center mains.
Wow thats a ton!
 

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set the torque wrench to 130 ft/lbs and tried it on my fluid damper. torque wrench clicked and didn't move the crankshaft bolt so I guess mine is all good :)
 
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