[nkaminar]

Liners are propriety alloys of ductile iron. As mentioned above, cast iron has the property of taking on a smooth shiny surface. Once that surface is obtained the wear rate goes way down. Race cars will use aluminum blocks with a hard coating, like silicone carbide, for the pistons to run on, but they are throw away engines and not expected to last long. Jaguar tried that for their production cars in the early part of this century and most of those cars are now scrap. They went to putting cast iron liners (sleeves) in their engines. Lesson learned.