The early B230 engines were designed for "low friction" meaning they skimped on bearings and reduced size of rotating components. In a na car these engines seem to do well, at least the couple I have, but the turbo places more stresses and causes the engines to wear out more easily. The later 230s are sig better with nearly all bottom components similar to the 23.

Turbobricks has a good review of the various engines and perhaps there is a review in Steve Ringlees FAQ in this site. 200 and 700s used basically the same engine so info crosses over nicely.

dick