crankshaft rod diisaster

Throwing my .02 in on the failure, it appears to be in no way oil supply related.
Assuming that no one was inside the engine prior to your ownership, it could simply be rod bolt fatigue brought on by overspeed / over revving. The loading on rod bolts that occurs during high rpm motion during the transition in motion at the TDC and BDC of stroke could potentially stretch the rod bolt, causing yeild that allows for the nut to loosen and the rest is history. If the bolts were marginally sized on the 550's for a given engine rpm limit, it would take too many redlines to cause a failure I would imagine.

Cory

Also if you had a rod bolt stretch fixture you could validate this failure mode by comparing to another non-failed bolt.

Lastly, it obviously didn't run that way long as with the cap being that far separated, you would potentially lose oil supply pressure due to the "rod bearing clearance" being hugh not far from the main supply rifle.

FWIW....

Cory

Good thing it was caught in time. Hope the new ones were torqued correctly.
Steve

NakedFun wrote: Throwing my .02 in on the failure, it appears to be in no way oil supply related.
Assuming that no one was inside the engine prior to your ownership, it could simply be rod bolt fatigue brought on by overspeed / over revving. The loading on rod bolts that occurs during high rpm motion during the transition in motion at the TDC and BDC of stroke could potentially stretch the rod bolt, causing yeild that allows for the nut to loosen and the rest is history. If the bolts were marginally sized on the 550's for a given engine rpm limit, it would take too many redlines to cause a failure I would imagine.

Cory

i never push my engine to the redline. i don't know if i understand well what you said. my english need to be improved :silly:

anyway i can tell the bike is ok now. since i installed the ''new'' crank and ''new'' cylinder block i have no problem.
bike start fine, run fine, a bit of blow by effect and i can see some very light smoke from the case ventilation port (i have a filter there)
i think this is the new piston rings setting the machined barrells. right? :dry:
bike run with foam pods, and is smooth from idle to 5/6kk rpm. i think i have to let her ''break in'' before pull more. i did for now only 30 miles...
is this correct? :blush:
i noticed that pod makes alot of noise under load, but i think this is not a problem. :S :woohoo:

shamal wrote:
bike start fine, run fine, a bit of blow by effect and i can see some very light smoke from the case ventilation port (i have a filter there)
i think this is the new piston rings setting the machined barrells. right? :dry:
bike run with foam pods, and is smooth from idle to 5/6kk rpm. i think i have to let her ''break in'' before pull more. i did for now only 30 miles...
is this correct? :blush:
i noticed that pod makes alot of noise under load, but i think this is not a problem. :S :woohoo:

Some smoke from that breather is normal. As long as you are not burning a bunch of oil or smoking out the tailpipe everything should be fine.

I'm a strong advocate of NOT babying the engine during ring breakin. Ride the bike around the city/town and use lots of throttle up through the gears. The idea is to get some combustion pressure building and get the revs up a little into the mid range. Don't go racing the engine to redline, nor lugging the engine either. Just some good "assertive" riding from stop light to stop light. After 100 miles you can use more throttle and pull the engine up into the higher reaches of the tach.

Good luck and have fun!