Question: Why did the plain bush last so well 60/70 years ago but does not fare well now?
One thing I didn't have a clue about when Bergs built my engine is the line boring, which I presume is how the bush is lined up with the crank???? Sorry if that's rubbish. I think, when RM built my engine originally, he just shoved a new bush in and chucked the rest together (badly). With Bergs and MWAS, the bush was engineered and line bored to the engine, and probably takes account of the amount of damage and wear to the other components. When everything was brand new, this may have been unnecessary. So, maybe the failure rate is down to the fact that bushes are put in without taking into account the tolerance variances of other components due to wear, etc??
I reckon the consensus is not a bad one, heavy, frequent and prolonged use may warrant a conversion. For the rest of us with empty pockets, the bush may have to do.