[PC/SR]

Dave: I am glad your inserts worked out for you. And yes your experience and that of all who use inserts has to be considered. The trick is to find out what and why it worked well for you and not so well for Eystein so that your experience and be repeated and shared and Eystein's avoided.

I assume the insert shells you used were for a modern production engine. As such, they would likely be thinner at the parting line than at the center, and would therefore create as sort of oil resevoir all the way across the parting line similar to the original model A design. I do not know if the AER inserts are thinner at the parting line, or if there is a V type relief there. There should be something there to create the oil resevoir and avoid the wiping action of a sharp edge.

The Snyder inserts shown in this thread have a parting line relief that is wide and closed at the ends, similar to the original reliefs on the A main bearings. If I were to use these inserts, I would file a small V across the remainder of the parting line and across the thrust flange to imitate the original A design.

I have nothing against inserts per se, and do not doubt that perfectly fine inserts can be designed for the Model A. However, part of the problem as I see it is that new and old technologies are being merged on a more or less trial and error basis. Nothing wrong with that and I admire the initiative of the guys that are doing it. I do not intend my comments to be construed as negative, but as something to be considered by the innovators and hopefully the final result will be something useful to all of us.

At this point, I think inserts grooved to the model A design would work best.