My reasons for bearing wear. one a lot of the drag guys don't give the bearings any running in, plain bearings need bedding in, run them in like Suzuki say and the bearings survive much longer. (2 hours on the dyno light load 1/2 revs would help). The other thing is that my cranks are Nitrided and very hard, std OE cranks are soft so no matter how good the finish is the bearings take longer to bed in. I have talked with bearing manufacturers and they all think that running a small bearing clearance helps keep the oil film between the bearing and the journal and that clearance should be between 7 10ths and 1 thou. I can get a ptfe coating on the shells up to 6 10ths thick if you have problems getting this. I have also source a much better shell for the 8.5mm cranks (40mm journal). Another improvement is to get more oil up to the bearing. I now do a 30% bigger oil pump (you can view it on my web site
www.tts-performance.com under hayabusa engine parts. Saval Racing will supply you one in the US. I have been told that the rod length (my rods are now 2mm longer)is not an issue on bearing wear but it is obviously on piston thrust. I live in F1 country (Cosworth are only 10miles from me). F1 engines run as compact an engine as possible this means short stroke and short rods. they run for a 2 hour race up to 18,000 rpm. I hope this will help you guys keep these engines together longer. Also don't forget to keep the oil level well up. I run 4.5 litres.
By the way I have only ever had one of my motors run a bearing and that was my stupid fault for running the oil at the bottom of the window. I ran a 1664cc motor on flying Kilo's, did 21 runs (flat for 2 miles) over two days and the bearings came out fine and that was with 120 bhp of gas on top.