Thanks for the suggestion. The rods might be OK and my tuning may need improving. Other folks using these rods have no issues. I might have less of a problem than I thought. Advice from the expert is "Finally, as race bearings go, yours actually look pretty good! My old mentor, who knew far more about bearings than me, used to say: 'expect some distress on racing bearings. It comes with the territory.'"
Advice from the expert. "Bearing clearance: Our bearing clearance recommendations are: .0017" min to .0022" max. As the bearing clearance gets larger, the bearing to crank contact area gets smaller. Your measured .0027" is a bit more than I'd like to see. As the contact patch gets smaller, the load gets higher, not what we want to see in a racing engine."
"Your suggestions for 2016: Have your white shells coated by a reputable bearing coater. The coating is about .0003" thick per shell and that would get the White Shell clearance down to around .002". The coating will also slow down the edge wear on the bearings, too. I have personal experience with three and can recommend any of the three.
1) HM Elliott in Mooresville, NC
2) CALICO Coatings in Denver, NC
3) POLYDYNE in Houston, TX
Beyond these three, you are on your own."
"All your shells are the same part number , so switch them around from location to location until you get the clearance as close to the same as you can. Measure with Plastigage. It is oil soluble so don't try scraping it off. Finally, use a prelube and oil brand and stick with it."
"Recommended bearing clearance calculations: .00075" to .001" clearance per 1" of shaft diameter plus add .0005" to final calculations for racing engines. Coatings are better than non-coated bearings. All 1/2 shell bearings taper from the center of the shell to within about 3/8" of the parting line by .0003" to .0005" each side. From 3/8 " of the parting line to the parting line, they fall off .001" or more in a process called parting line relief. All clearances are calculated at the center of the shell."
The basic advice I get on the internet and from conversations with a lot of late model Triumph tuners is "use white shells." The expert's advice goes beyond that simple statement.