[Werner]

Brendan,


I can't say that specifically about the A motor. But in the past it was generally thought that there should be a groove in plain slide bearings in order to transport the lubricating oil.

It was later researched that these grooves disrupt the hydrodynamic lubricating film. Therefore, sliding bearings without a groove in it are used nowadays. That's better.

Perhaps because of this someone used more modern bearing caps on your engine?