I assume that this subject matter may have been dealt with previously, but what still intrigues me is why Volvo would have progressed to an overhead cam engine. I know that the engine mountings, gearbox bellhousing, sump and waterpump would require adaptation for fitment into a 122.
My questions are:
1. Assuming that the adaptations above could be managed, and supposing that the bottom ends of the B23 and B20 are similar as far as crankshaft and conrods are concerned, which engine would perform and be tuned better?
2. Are there certain limitations to the B23 cylinderhead, which allows the B20 to be tuned better?
3. Would the engine noise levels be lower with the B23?
4. If the B23 engine is mounted upright, how will it affect the lubrication of the camshaft, if at all?

You kind assistance will be appreciated.