Well ....many of you had great answers.......
Anyhow I observed 2 or 3 problems here.
1. The operator attempted finished size to be at 2.938.0......Operator must not have had bore guage correctly
calibrated as finished size average was 2.939.0 and then some...........
2. mains must have been pretty bad...as at the parting line the block was peened very heavily.
My thoughts...too much material removed off the main caps w/the cap grinder to try to bring back to size.
3. The mains were not " Bored " and then honed to finish size."......Honed only...(Too much material to remove for
honing alone ! )
Finally........It look's as though the stones were worn causing the tapered effect, as well as not rotating the block
during the honing process..... and not enough cool down time....I practice getting sizes close, cool down then go back
the next day, re-calibrate mics. and finish to size.
For those of you who have ever resized connecting rods....the process for main work is very similar........................
Just MHO....
