How to analyze marine engine crankshaft deflection?

New engine or new crankshaft?

• I have a 1999 Saturn sc2 with a knocking engine. My dad, whose a mechanic, said the whole bottom end is shot. He said it needs a new crankshaft. I was thinking of going to a local junk yard to find a new motor, but I found online crankshaft kits with bearings and everything for around 200-250$. My dad can put it in, that's no problem but which should I get? Because the car is in great condition, only has 57000 miles on it. Any help is appreciated.

• Answer:

  if it hasn't damaged the rods in any way id put a crank kit in it,its cheaper to do this,but make sure its not damaged any of the rod bearing mating surfaces on it,if it has it would be cheaper to buy a good used low mileage engine for it,good luck with it.