I have a GM 350/5.7 marine petrol engine. The block has a large crack due to freezing. The engine itself doesn't have that many hours on it, so the other parts should be quite OK.

Is it possible to change just the block? Move all the valves, pistons, head, crank etc from the old block?

Does the new block need to machined?

  • Have you thought about getting the aluminum block welded?
    – user16128
    Feb 1, 2020 at 14:31
  • It's cast iron, but welding is one possibility. But i would rather get a new block. Feb 1, 2020 at 14:54
  • The cost of competent labor likely makes a replacement engine a little less costly. Welding cast iron is risky ; even if inspection shows it is not cracked after welding , it is a significant possibility in the future. I think you need a "short block" ; a complete block without heads, manifolds, etc. Feb 1, 2020 at 16:10
  • The problem is this engine is reverse rotation and has therefore (and because of the marine application) a peculiar crankshaft. Feb 1, 2020 at 17:12
  • Welding a cast iron block is possible. And did it once for a v8 that had frost damage - worked fine for years... If you are not a good welder though...
    – Solar Mike
    Feb 1, 2020 at 19:56


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