Why precision match dowel cranks to the flywheel together as a married unit at one time and not dowel them separately? Because few people do it properly and we do not wish to have our crankshaft's reputation damaged by it not being done properly by someone else.
In 1961 we began installing 11/32" dowels in hopped up 40 HP engines. The reason was to get more contact area holding the flywheel for drag race starts. As HP went up and tires got better, just adding the dowels was not doing the job, a few were still loosening. Research showed that unless the crank and flywheel were doweled while bolted together, and kept together as a married unit for life, little was gained over the stock 4 dowels. It was impossible to get the identical alignment or fit when done separately.
We perfected ways of mounting the flywheel to the crankshaft so we could ream the holes together for perfect alignment and proper interference to one another. We discovered there was no way to do this when the parts were done separately because the drill, reamer and machine driving them always have some run out and wander. Making a reamer that produces the correct hole size was also tricky. We grind it to create 0.0012" to 0.0018" press fit from the crank to dowel and 0.0002" to 0.0005" through the flywheel. Few people are able to perform this precision work. This is why we include match doweling in the price of our new Gene Berg forged cranks and highly recommend you add this service to any of our counterweighted crankshafts that do not include it. It is critical to alleviate the possibility of the flywheel parting company with its crank. This also allows us to check the flywheel run out directly on the crank it runs on.
We do not dowel or balance our cranks until we get the order because we do not know what your flywheel needs are. This means we take an extra day or two to ship your crank and flywheel order. Developed by Gene Berg 1961.
Note: Be clear that not having a flywheel come off is also dependent upon the use of the proper mounts and suspension parts that eliminate wheel hop. We cured all of these problems years ago and are experts in this field. See Berg mounts, mount information and GB 801-SUSP, suspension technical article, which is mandatory reading.