here is a nice bit of info on the base engine:
http://www.zimbio.com/Look+at+BMWs+M...gine+In+Detail
The more I look at it the more I can see Judds logic for using this engine, basically the throttle bodies can be carried over, externally all they have done is add the trumpets........cost wise this is really significant, on the Nissan IES V8 these parts (throttle bodies & manifolds) are bespoke parts = more cost.......internally I'm sure Judd have used bespoke valves, pistons, rods & crank.
One thing that worries me about this BMW engine is the cylinder bores - from my personal experience of BMW V8's, the alu-sil bores are very prone to scuffing on a race motor, the pistons basically run directly on the on acid-etched aluminium, whereby the silicone sits proud........its OK for a production engine, but once you tune it we found you had no choice but to nikasil coat the bores, at a cost of several thousand pounds........which is not the end of the world, but its certainly needs to be done.
Judd seem to be getting excited by its low weight but dont actually quote a number.........for reference the IES Nissan is "less than 150Kg".......but does it really matter now that LMP2 cars are going to be so much heavier.......I guess it allows a team to play with ballast placement.........just noticed the Sodemo lump is 140Kg.......so it looks like both the Nissan and BMW are comparable weight wise.