Micropolish, Chamfer & Balance Crankshaft

The first step in understanding crankshaft balancing is to understand the purpose of the counterweights. The counterweights are designed to offset the weight of the rod and pistons. You have the weight of the crankshaft and the pistons and rods. At any point in the assembly’s rotation, the sum of all of the forces are roughly equal to zero. If the counterweights are the correct weight to offset the weight of the rods and pistons, the crankshaft is balanced. If the counterweights are too heavy, material must be removed by drilling or milling the counterweights. If the counterweights are too light, weight must be added to the counterweights. This is usually done by drilling a hole in the counterweight and filling the hole with “heavy metal” or “mallory”. This filler metal is denser and heaver than steel (but not stonger) so the weight of the counterweight will increase as a result.