Posted by Bob Moriarty on December 23, 1999 at 00:16:45:
The following describes the damage found after an engine failure of a 230 cu in flathead B-3PW. Wrist pins of #3 and #6 connecting rods had walked so far out of the pistons that the cylinder walls were gouged. The rod bearings of #3 and #6 had spun and damaged crankshaft. Wrist pins of other connecting rods were working against the wrist pin keepers to the extent that the keeper slots in the aluminum pistons were deformed and near failing. The rear face of the rear main bearing showed evidence of metal-to-metal contact with the crankshaft but the seal appeared undamaged.
The engine had been completely rebuilt about 5000 miles prior to failure by a reputable(?) mechanic. There was adequate lubricant just prior to loss of oil pressure and engine failure.
Piston manufacturer suggested possible causes were improper clutch adjustment or bent connecting rods. (The rods were NOT bent.)
If anyone has experienced or heard of a similar failure we'd appreciate suggestions regarding the cause. Still Searching!