I'm rebuilding a t motor dating December 1920, sat outside roughly 50+ years braving the elements. Everything looks to be well pickled. My question is , If my crankshaft passes the mag test, should I have it shot peened?
I always glass bead mine and then wet mag them. If it passes then the crank grinder does his thing.
Shot peen is a way to add compression stress to the surface. Since things tend to break due to tension stress at the surface, the compression stress counteracts this to some degree and makes the part stronger. Since the crankshaft breaks due to fatigue, in my opinion a crankshaft that has had few hours on it would be a good choice. I am not sure what good shot peening would do for fatigue failure.