Quote Originally Posted by Z3_GoCar View Post
Well, here's proof they're Frankenstein's from the factory. I looked up the crankshaft part number, and here's the cars that share the same part number for this crankshaft:
James, you can't do it, period. These aren't frankenstein motors. A frankenstein motor is a motor that's been built from combinations of parts that were never available together.

All of the engines that the 2.5L crank was in were 2.5L engines (go figure). So you can't put one in 2.8L block. What you *can* do is to use any BMW 2.5L engine you want to (and, you can piece one together using parts from your 2.8, but the result has to be identical to something that came stock in some US BMW).

So the question to ask is, which 2.5L do you want to build? I'd recommend an M54, but it would certainly be easier to build an M50 given what you've got in the car now, since you can keep your current head and intake manifold.