I have a 2004 D2, and was wanted to learn some about the engine. I read something that it's an American engine, but before it's put in the Rovers, the Brits do something to it before. Anybody have any information I may not know? Thanks.

 

Your Disco engine was designed and built in 1961 by GM and was used in some Buicks and Olds. Rover bought the rights and equip. to make it and it has gone from the 3.5 to a 3.9 to a 4.0 to a 4.2 and the 4.6 mainly by stretching out the stroke.
Hope this helps.
Mike