Reply To: Rod autopsy

[Randy Roberson]

Never saw rods chipped like that; have seen many old thick-Babbitt bearings like those. Thick Babbitt has lower strength and there can be problems with the initial bond as well as it starting to disbond and break up late in life. Sometimes pieces of main Babbitt find their way into the crank oil passages and into the rod bearings and rod passage to the wrist pin; sometimes the oil pan, sometimes smeared on the rest of the bearing, just as Greg said.

I have seen bearings with these defects run a long time undetected and I have even seen the time when the men would be forced to get one which had previously been discarded, blend out the edges of the failure, and run it, because they had no choice.

These are large engines not car engines, of course, but similar principles etc. as they were designed and built in the same era.