"Dry sleeves are named so because the sleeve body is not exposed to any cooling liquid within the block and is always installed in a block with an interference fit. Darton manufactures ductile iron sleeves for dry installation in aluminum blocks with special surface finishes and recommends that aluminum block cylinder walls be lightly honed with ""Brush Research"" bumble hones prior to sleeve installation. The combination of male and female surface preparation greatly enhances heat transfer when the sleeves are installed and fit properly."