Cylinders Twelve cylinders consisting of high-carbon steel, floating wet liners[15] set in two, two-piece cylinder blocks of cast aluminium alloy having separate heads and skirts. Cylinder liners chromium plated in the bores for 2 1⁄2 inches from the head.[15] Cylinder blocks mounted with an included 60-degree angle onto inclined upper faces of a two-piece crankcase. Cylinder heads fitted with cast-iron inlet valve guides, phosphor bronze exhaust valve guides, and renewable "Silchrome" steel-alloy valve seats.