[Reed]

I am just curious as to what kind of materials have been used in engine blocks over time. OF course there is aluminum and iron, but i dont know if there have been steel blocks. what would be the advantages of this over an iron block. I am assuming it would be stronger but am not sure and would it be any heavier or lighter. (I'm no metalergist) Have any other metals been tried in engine blocks. How about composite materials or ceramics?