According to James Taylor in his book "Rover V8 - the story of the engine" published in June 2017 by Veloce Publishing Ltd there is a rather convoluted path of possible inspiration between the BMW V8 and the Rover / Buick V8.
He says that the BMW engine has design features that were clearly inspired by by the first post war American overhead valve V8 engines. In particular those used by Cadillac and Oldsmobile were of very similar layout, albeit rather larger. It seems that these engines would also have been used as inspiration by the team designing the Buick 215 motor that was to become the Rover V8. Given the similar sources of original inspiration its pretty certain that the Buick team would have looked at the BMW motor to see how well the American layout translated from cast iron into aluminium and what modifications were needed. James suggests that the cylinder block stiffening webs and similar structural features are sufficiently similar to suggest that they are BMW inspired. My alternative view is that the American design teams were using the same textbook calculations. So any BMW link was more along the lines of confirming that what was expected to work would work in practice. Well more or less as the basic block stiffness of the Buick engine was always rather inadequate.
In Rover ownership there was always a pretty continuous process of modification to improve stiffness to keep up with power increases. Normal for the period really because inadequate block stiffness as designed has been a pretty common feature for aluminium block and head engines. Allegedly the current generation have finally nailed it but we shall see. Cast iron is such an incredibly forgiving material that designers often fail to understand how much they are exploiting undocumented characteristics. Aluminium isn't as forgiving. A major reason why the Leyland K series uses through bolt construction. About the only reason that horrid confection Leyland put in the Stag doesn't suffer from terminal block issues is that everything else goes pop first!
Never understood the near-deification of BMW designs. The straight 6 being, in my view, a misguided exploitation of far too many pushrods in pursuit of inadequate inlet gas flow arrangements. Don't mention the idiot VANOS system or L322 installations (actually don't mention the L322 period). At least BMW didn't manage to muck up the P38. Always think it a darn shame that the Rover V8 never got the four valve head and other updating allegedly originally planned for later versions of the P9 sports car after Bill Lyons ensured the project would be dropped as being cheaper and better than the E-Type.
Clive
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