Sharks Teeth

[GNTurboTommy]

I Picked up a 87 GN 109 short block to rebuild. The inside and outside had all sorts of sharp castings every where. Even the rods had a "seam" and the crank had sharp edges (unmachined)casting marks? Shouldn't these be ground down and buffed smooth? I was wondering also how much could the journals be machined and still be on the safe side? I would believe these to be areas where stress cracks could occur. Thanks Tom

 

[turbofabricator]

Stress "risers" are what you are concerned with. The stock rods are good to over 600 HP as-is. More if beam polished and good bolts, but to be honest, I have never seen a broken stock rod, plenty of bent ones, but never a broken one.
You can safely turn a stock crank .030" with no problems. The stock crank has rolled rod and main fillets and rarely will you grind significantly past the compression rolling.