Ok, just to clarify, the engine was designed by Honda, as their 2.7 V^ was a great engine but had poor emmisions. Honda designed the engine and hand built the early ones under an old agreement to Rover ( honda needed to get more units built for their USA cars badged as Acura). the 800's took the engine but it was a constant problem for Rover as the engines varied from engine to engine due to the hand building and the tolerance stack up for cylinder liners causing over and under compression on head gaskets. BMW came in and redeisgned the process ( delaying the initial launch of 75's until BMW signed off quality as being consistent). Contrary to poppular belief, the Plastic Manifolds and VIS are NOT rover design but BMW design. Rover designed the VIS to be metal, but BMW veto'd that). see here
http://en.wikipedia.org/wiki/Rover_KV6_engine
I would love to be able to put the old 2.7 Honda lump in a ZS.