[Christ]

Yes, I actually changed the design to something more... proven.

A torque converter. It's already the proper shape, no modification [other than cutting and gutting] needed, I can bolt it directly to the existing flexplate, which bolts directly to the end of a crankshaft, which I can have a machinist center drill, cut a keyway, and re-balance for me, enabling me to sit the whole assembly on the motor head like a hat of sorts, and we all already know that torque converters on average can spin 7k+ RPM FULL of fluid and counter-rotating forces inside them without blowing apart at modest power levels attached to automobiles, so I'm thinking it should be fine [i.e. less potentially catastrophic] spinning at 5k RPM generating ~5,000g with about a quart of oil in it. [probably less in practice]