Old Iron Works has researched various profiles of the machine work required to lighten the Model A flywheel. This reduces the weight to approximately 41 lbs. It involves removing material from seven surfaces and includes machining four radii. This reduces the weight to about 36.5 lbs. Nine surfaces, five radii, and two chamfers are turned.
All flywheels are bead blasted, machined, surface ground and dynamically balanced.
Those sold with clutch and ring gear are balanced as an assembly and marked for proper positioning. If the customer purchases a bare unit, it is highly recommended that the flywheel be balanced with the customer's clutch and ring gear prior to installation. If the customer is not satisfied with the product, either a replacement product or a cash refund of the full purchase price will be made. These flywheels are up to seventy years old when they are machined and all machined so far have flaws and inclusions in the original castings. Although we have never heard of a failure in service of any such flywheel, we have no control over the use, abuse and application to which these units will be exposed.