MM33-FO5 Felt Set, 3.3" to 4.2" Range Honing Stones for High Silicon Aluminum Alloy Blocks
Use these felt "stones" to lap high silicon aluminum alloy cylinders. Apply a coat of Sunnen Silicon-Compound (AN-30) to the felt and the cylinder surface. When finished, the cylinder will have a matte finish. Pistons and rings will ride on the siicon instead of on the aluminum itself.