Porsche TransAxle Adapter & Runout

I just read the article on Chris Baker's LS3 powered Porsche. Looks like fun. It causes me to raise a question here that I've been seeking elsewhere.

I am building a GT40 that will incorporate a small block Ford with a Porsche G96.01 transaxle. Between the two is an adapter plate and special flywheel to make all the pieces play nice together. The question comes up about clutch runout. On most all American V8's, we're taught to set the crankshaft to bellhousing/transmission runout within a certain spec. Recognizing your trying to reduce tolerances from multiple manufacturers and get the transmission input shaft directly inline with the crankshaft.

When adapting to a transaxle, often the bellhousing is a part of the transaxle and you do not have a surface to indicate to the crankshaft centerline. Any suggestions or ideas on how to determine the transaxle centerline in this case?

One could indicate the crankshaft to the adapter plate for one side. But for the other side, mounting the indicator on the input shaft, 9-10 inches out from the support bearing, I question how accurate that could be. Yet that appears to be the only thing that the indicator could be mounted to. The Porsche transaxles generally are pretty closed up and no room to get inside to check with a dial indicator

Talking to the adapter people, who I admit, have more knowledge on this than I, they say "just bolt it up and go" Am I being too anal on this? I've had considerable issues in the past with a TKO style transmission when it wasn't aligned properly. And I know very little about how Porsche does their engine swaps

thanks

Paul

I think the precision of the Porsche bellhousing bolt holes and dowels is a lot better than the fabricated bellhousings often used with the TKO-style transmissions. I raced a 914-6 for a number of years, and never worried once about bolting the engine / transmission together. This continued on to the sports racers I run now, with Hewland gearboxes and long input shafts that go through the oil tank / bellhousing. We just "bolt them up and and go".

I do have a Quaife G50 gearbox case/housing, somewhere, but unfortunately no innards.

But you may be able to fabricate a precision sleeve to slip over the input spigot (slight interference with a warm fit?) and use that to triangulate to the dowel positions. If the gearbox is on-end, it should be in the "natural" position.

Then compare that to the crankshaft spigot bearing centre to the dowels.

It's going to be finicky, but unless you can find engineering spec's for their relationship, I don't see an option.