I am somewhat familiar with aluminum Porsche 944 and 928 engine blocks. There is a special process to cast silicon in the walls to make them hard, and pistons are plated with iron to make them compatible. There is a special process to remove a thin layer of aluminum in the bores exposing only the silicon to the rings. Silicon (refined from sand) is what electronic chips are constructed from, is not to be confused with silicone!
If the blocks are just aluminum, they will need sleeves or Nikasil, a trademarked electrodeposited lipophilic nickel matrix silicon carbide coating. Unless one knows what the block has, it could be expensive to process for use.