Ranger Biodiesel Swap - Flywheel Adapter Fabrication Part 2

 This adapter requires extremely tight tolerances to prevent vibration and misalignment with the flywheel, so the manufacturing process must be careful and precise. This is complicated by the design of the final part, which has alignment surfaces on both sides of the face, both radial and flat, and on inner and outer diameters.

Every time you remove and reinstall a part in a three-jaw chuck, it introduces a minute amount of misalignment in the part, especially in older worn machinery. In order to maintain accuracy through repeated removals, I manufactured the fixture collet (previous post) that has multiple precise ridges and two methods of retaining the part with bolts. These ridges correspond to ones that I will machine in both sides of the adapter, so that the piece will always be perfectly centered on the fixture no matter how many times it is removed and flipped.

The adapter started life as a 1-in thick round steel plate, and I drilled a hole through the approximate center the same size as the center bolt on the fixture. This allowed me to mount the plate in the fixture, and start machining the outer diameter and first face.

The stepped ridge on one side of the adapter is the primary alignment for the flywheel, so I machined the outer diameter to a tight tolerance against the inner diameter of the original Ford flywheel. 

Once completed, I flipped the adapter to the other side, aligned the ridge with the corresponding pocket in the jig, and locked it in place with the bolt. I then machined the opposite side flat and added another ridge for alignment in the other jig pocket. 

Once complete, I removed it from the jig and test fit it on the flywheel

The next lathe step required center boring of the adapter for the crankshaft alignment and transmission pilot bushing. This meant that the center hole would no longer be used for attaching the adapter to the fixture, so I first had to drill the radial bolt patterns. 

I mounted the adapter to a rotary table on a drill press with an XY cross slide, and drilled the inner and outer bolt patterns.

With the bolt patterns finished, I could then install the adapter on the jig without using the center bolt, and finish boring the inner diameters for the crankshaft alignment and pilot bushing