[Christ]

Originally Posted by Jasen

How about welding plugs in the old holes, then drill and tap your new holes. Cut the plug's the exact same length, turn/have turned and balance checked.

I thought about that, but money will quickly become an issue. I can probably find some .504 press fit plugs cheap enough and press them in myself, but then having it ground and rebalanced for the plugs in addition to having the center milled out and the rear face widened will up the cost considerably.

I have an engineer friend I'm going to talk to about drilling 5 of the 6 holes centered between the existing pattern. The offset hole on the new crank is 12* off from standard 6-hole and will likely intercept one of the existing holes, and it may be well enough to place the bolt within the existing hole. If he says it's OK, I'll take his word for it. Not really all that difficult to pull an engine and replace a flywheel if it doesn't work out.

Also, as a last resort, I'll talk to ACT or some other flywheel company and see if I can get them to mill a Festiva flywheel with the Mystery engine's pattern in the center... shouldn't cost me more than a 'custom' light weight flywheel, since they already make components for both engines. It'll just be a matter of changing the jigs and tooling halfway through the work order.