rebuilt engine leaking oil....

[Bob Kneale]

I run a ball race in the rear bearing of my engine, but that's in conjunction with a very carefully fitted flywheel.
The objective is to retain the axial movement of the crank at the rear bearing, not the front lip.  However, the grinding of the spacer that goes between the flywheel and bearing is a job where a couple of thou is important. It's a Frank Hernandez suggested mod.

Charles

Using a ball race in the rear main bearing is a modification I have considered for years, but apart from sourcing the bits, haven't yet got around to it yet!
It would be at its most beneficial in a 3 bearing engine, where it would isolate the thin center webs from the bending forces that surely occur when depressing the clutch pedal puts a heavy axial load over the full length of the crank. Leaving the front bearings floating (as in a modern plain bearing engine) is surely kinder to the crankshaft, particularly under normal i.e. non racing conditions. The gyroscopic loads on the flywheel might be a problem when cornering, but only slightly more than with  a roller race.
We'll never know if we don't try it... Here's to a healthy discussion!
Bob