Bad bearings or bend rod? Quick quiz

[Hammy]

I replaced a motor with an old one I had kicking around. When I started it up it ran perfect. Then I went around the block, and it started knocking exceptionally loudly, as if I had spun a bearing. Oil pressure was perfect, and the needle wasn't bouncing around as if a bearing was done. I changed the injectors over to the ones from the motor that came out, and noise was gone. Bad injector!!!