Engine Bearings

[Roesbery]

I see on the Superior website that they claim to be keeping up with the Joneses ( Lycoming ) by having new and improved crankshaft bearings. Looking on Lycomings' website shows new bearings for the IO-540 engine, didn't see anything on smaller engines. Have any of you folks had problems with the current bearings of either Lycoming or Superior, or know of anyone who has???? If bearings have been running for 40+ years and 1000s of hours with no problem, and since then somewhere along the line a " new and improved" bearing is having a problem, what are the chances of a newer improved bearing being trouble free???? Any thoughts????

[jrenwick]

The only "problem" with main bearings for the O300 and C145 that I've ever heard of is the possibility of installing them in such a way that they're not properly seated in their journals. This leads to cracking of the journal webs inside the crankcase. I have a crankcase that I'm told was damaged this way, and someone on this forum noted another one within the last year that sounded to me like the same problem. If this could somehow be "Murphy-proofed," that might be a good thing. This is all speculation on my part -- I haven't heard anything on the subject.