I took my case and new bearing to Jerry's Triumph in Little Rock today. He held the bearing up to the case bore and said "no problem." When I explained how the bearing had been loose in the bore even after it had cooled quite a bit he just said that he had never had a problem with one and generally didn't even use LocTite. (had only used LocTite in the very worst of fit.)Thanks for the reply.mr.pete said:Loctite won't prevent thermal expansion.It's useless in this case,and the bearing will still roll around in the crankcase when the engine heats up.
Even with 0.0025" interference,they still do some rolling around,even when Loctited.At 0.0025",it doesn't create much of a problem.
You probably need to get the outside of the bearing hard-chromed or nickel-plated,to make it bigger.Maximum recommended interference fit is 0.003".If it's tighter than that,the bearing may not turn freely,even with a C3 clearance bearing (which you should be using on the T/S).
I don't have an inside micrometer with which to measure the case bore but I have a friend that probably does. I'll try to get some good measurements before I proceed.
So. Answers to my question have been all over the place and I'll now have to make some decision about how to proceed. My machinist friend measured the case bore and the bearing OD and came up with the bearing being only about .0005" to maybe .001" larger than the bore. i.e., not too snug!
Hard chroming the bearing is not very feasible for me but maybe other plating options are (e.g., zinc plating.) Does the plating material really matter here? Would .001" of zinc be as good as .001" of hard chrome?
Better than trying to shim it I think and electrolysis shouldn't be an issue here.
Thanks for any info.