Re: Curious... balancing a SBC 400 vs other SBC\'s
Matching the weight of the pistons and rods is just part of it. After that, you take the weight of a piston, rings, pin, and the top half of the rod to get your bob weight. The crank is put on a balance machine with the dampner and flexplate installed. It is spun at around 500 rpm. The crank is balanced one half at a time. Balance can be adjusted by drilling out counter wieghts to lightnen or by drilling a hole in a counter weight and installing heavier metal slugs in the hole, mallory the metal is. It is expensive. Doing it this way you could balance a 400 crank internally. Stock car guys do it due to the type of direct drive or small clutch set up.