How to hot run a Studebaker V8 set up for automatic transmission ??

[jclary]

If "making" a flywheel for this purpose, once could use a countersink on the bolt holes, and then cut a 45-degree bevel on a set of nuts. That should give enough thread engagement for the purpose.

OK, Gordon, that suggestion stumped me for a moment. Took a few minutes for the morning caffeine to clear the fog.

It's been well over twenty years since I did my backyard overhaul on a '60 Lark 259 automatic. Back then, I had no test stand but had all the sheet metal removed from the front of the car so my chassis was about as good as a test stand. Therefore, I never gave a thought to doing anything other than bolting it back to the transmission to run the engine. This is a subject that probably few of us occasional tinkerers encounter in the same way, professional builders do that may not have available the vehicle in which the engine is to be installed.

Without enough experience, I can not accurately imagine how much thread is available on the flexplate bolts when attaching a standard flywheel? If I recall correctly, the bolts are fine thread, so at least there should be a few turns of contact. Apparently, some of you have done it successfully. My question regarding the countersink (like mini-lug nuts?) would be how accurately the bevels of the countersink match up to the bevels machined onto the nuts? If done perfectly, you improve percent of thread and mating surface contact. However, if the bevels don't match up well, you could have a better percent of thread contact between the bolts & nuts, but lose surface grip (bite)?

Since some of you have already had success without additional machine work...we are probably engaging in "over-think," which can cause extra work and inhibit progress. So, Jack, if you bolt up a flywheel to the engine with the short bolts...please post a picture so we can see how much the nuts thread on. Also, anyone who has done this, did you use a torque wrench? How much torque?