28-04-2021, 09:05 PM
First question is: shell rods or Babbitt rods? If Babbitt rods, you will need to blue them up with a light smear of engineers blue, tighten them until the will just turn and turn the engine over a couple of times. Remove the caps and see where the crank pins are touching. The blue will have rubbed off. Scrape gently where it has, blue up again and repeat the process. Keep on repeating the process until each bearing is no longer tight. The cognoscenti say that, with the crank and rods out of the engine, ,when the rod is put at right angles, it should just move to the bottom under its own weight. Personally, I have cheated a bit and scraped them with the engine built up until the engine turns easily with no sideways play in the rods. The rods should have a tiny bit of endwise movement (just a couple of thou) along the axis of the crank pin.