Nice to meet you here manuelf. I missed this thread.
I do not understand why so many want a 6 cylinder engine for the M2. If you want a 6 cylinder engine, or even an 8 cylinder engine, you'll ahve the M4 or even the M6.
What keeps me away from the 1M is the 6 cylinder engine. Remember the M3 E30 had an I4 whereas the 325i E30 has an I6.
For the M2 an I4 has only advantages over the I6:
-even if an I6 could get more power, BMW won't give it more because it would step on the M4 which will also have a 6 cylinder engine, so an I4 would get the needed power
-the I4 would be lighter than an I6 and thus the car will be less front heavy
-the I4 is shorter than the I6 so it would have better weight distribution
An N55Tu will not be M worthy, 1M was an exception, and S55 would be to close to M4. N20Tu would not reach reliable 350 PS from its 2.0l engine, and in general there is no reliable possiblity of increasing bore of both N20 and N55. The only possiblity left, and the best one, is half a cylinder bank from the M5 engine, so a 2.2l I4. An other possibility is to add two cylinders to the N16 engine, it would then give us a 2.4l I6 making 315 PS, if too keep the same numbers as the 1.6l I4 making 210 PS. But I think it would be too costly.
It is too early to know, but IF the M4 really get the 3.3l V6 derived from the 4.4l V8, I am 100 % the M2 will get the 2.2l I4 also derived from the 4.4l V8. The M4 with the V6 will not please everybody, but will perform better. For those that the 4 banger of the M2 will be insufficient they'll always have the M235i and 435i.
I would like Scott to chime in and make this point more clear or confirme some of what we said. I am really looking forward to this car, I was quite disapointed by the 1M.