4.4 vs. 4.8
 

Is the 4.8 a stroked and/or bored 4.4?

no, the 4.8 is a 4.6 with a different stroke, and a 4.6 is an alpina designed motor

Actually, the 4.8is IS a bigger version of the 4.4, both based on the N62 motor platform for 04+ with the valvetronic and double VANOS. The 4.8 is the N62B48 and the 4.4 is the N62B44.

4.6is is based on the M62 motor platform (M62B46) without valvetronic.

he's talking about the block itself, the m/n just means valvetronic or not, I remember when the 4.8 came out C&D did an article and said that the way they added the extra power was to change the stroke on the 4.6 and add valvetronic

Even with that argument, the 4.8 is still a bored 4.4, both with double VANOS and valvetronic since the 4.6 does NOT have VANOS or valvetronic.

If he's talking about the block itself, then all of them share the same block.

http://en.wikipedia.org/wiki/BMW_M62

http://en.wikipedia.org/wiki/BMW_N62

I stand corrected, I'm glad there are people that are more knowledgeable than I