Bad rod bearing

[Werner]

SAJ, I meant to grind the connecting rod caps with the inserted bearing shells together on a lapping stone. Only some few µm.

[SAJ]

Werner Yes I was sure you meant that. I was worried someone less knowledgeable would think you were grinding just the insert shells.
If you leave the shells in the caps and surface them on a stone, you will remove the protrusion of the shells and the crush which is important for tightness and bearing shape. That is why I stoned the caps without the shells in place. I could have then removed 0.0005 inch from the shells to retain the same crush, but did not bother. So my bearings have a very slightly bigger lemon shape than before I resurfaced the caps.
SAJ in NZ

[Werner]

Wunderschönen guten Abend!

Since the day before yesterday my machine has been running again with the new piston rings and the inserted connecting rods.

Yesterday I drove 40 carefully miles with less than 40 mph. The motor now runs as quiete like a freshly oiled sewing machine.

I would like to thank now all the helpers here who supported me with advices!


Info: The new 'imported connecting rods' with inserts weight 775 grams. The old ones with babbits 720 g. The weight difference are only 5 grams.

[Werner]

N'Abend!


After now 430 slow (max. 40 ml / h) running-in miles today I measured the warm engine compression. 70 PSI at all cylinders - it's looking good!