The principle reason that Poms lurv their Rover V8s is that they don't have the readily available supply of really good GM and Ford Engines as they must be imported from the US of A .
You can probably get a Rover to produce near respectable BHP, but the cost is horrendous. 220BHP--that's standard just about for Yankee iron without girdles (to hold the crank in). Or even a bra and panties.
318lb would not have too many accessories on it, and its still about 145 Kg. ( more than 50% heavier than an A Series, and the gearbox is still to come).
Sorry, BCF,the main reason that you are not able to convince me is there has been no compelling argument put foward. Before I go home for a beer, I'll make two points---(1) The Poms traditionally make an engine design for far too long after the World has moved on. If you dont believe me have a look at the Jag XK engine and nearly every thing that Austin, Morris, BMC, BLMC, Leyland and Uncle Tom Cobbley ever made.
(2) When they had a really good V8,---the Daimler Majestic Major, they canned it.
Its pretty clear why they don't own a proper motor car industry any more.
To Be continued (if necessary)