Rebuilding a 1993 D16 engine.
after install pistons and crankshaft i test turned the crankshaft counter clockwise
get a slight scraping sound on 1st and 3rd quarter turns with a little resistance.
2nd and 4th quarter turns are smooth and silent.
any ideas as to cause?

 

did you clean the internal parts before installation? Noise is likely the motor building compression.

 

thanks for the reply. Yes new pistons and rings, oversized and bore honed to match by a shop. Rings within spec. Oiled before install
all cleaned too
no head on block when I tested crankshaft turnover
its strange it only happens in first and 3rd quarters of counterclockwise rotation

I put a torque wrench on it and 1st & 3rd quarter turns need 20 ft lb
2nd & 4th quarter turns are 5 ft lb
new thrust washers, pistons, rings, main and rod bearings
assembly lube on all parts
pistons and rings oiled up