From a manufacturing engineering point of view the large feed hole in the case makes it cheaper and easier for the feed hole.in.the bearing shell to always line up. It will also allow a change in flow rate up or down by changing the size of the hole in the shell, instead of changing a case.
It seems to me Neil is suggesting drill the oil hole in the bearing out to.the full size of the case.
I guess my question is, should I make the chamfer a bit bigger Fred or do you think this is good? It's maybe 1 mm on the one shown above.
The first few done with a drill bit were larger.
Neil, I respect the wisdom and experience you bring to this forum, but your above response didn't really hit the mark for me. Carefully rebuilding a Porsche engine is not obvious or simple. Your answer while interesting was a non answer because no details about your preferred bearing hole were provided.
I don't plan on putting this engine together based on my best guess of some half described detail. I find it's always better to ask questions and practice something you have never done before, especially when your following verbal instructions from a subject mater expert, thanks to Fred Apgar and Peter Dawe for providing me with some very helpful suggestions.