Balancing in the automotive trade is a term used for weight matching all the rotating components in an engine. For example, all moving pieces such as crankshaft, flywheel, clutch and pulleys are spun balanced as seen in the pictures, then weight is either removed or added to correct the harmonic vibrations of the rotating assembly. Pistons and rods are weight matched on a gram scale. Normally the factory would match these items to 4-15 grams.
At J and M Machine balance the items to less than .5 grams so there is noticeable difference. Babbitted engines benefit greatly from balancing as there is no way to control the amount of babbitt poured into each rod. Therefore, by correcting the weight by weighing and then correcting each rod a smooth engine is the desired result.
Owners of Model A's for example can attest to the difference of a balanced engine. We use a "CWT 5000" balancer which is the most advanced computerized machine where balancing is concerned.
We are able to provide customers with a printout of all specifications of before and after balancing as well as a "Bobweight card" for a record of all component weights for reference and future needs.