What engine did SMG used? Why don't Nintendo use it in SSBB & MK Wii?

[DarkNight_DS]

BengaBenga said:
Nintendo creates specific engines for each of their top tier games, in order to optimize the performance of that game.

For example the Galaxy engine was mostly built around dealing with the gravity of the spheres.

The benfit is clearly that you don't have to put in stuff you don't use, so the power of the console can be fully used for the processes that matter.
Of course this is much more expensive.

 Yup, you nailed it...  Nintendo has stated in the past that each of their games gets a unique engine.  They rarely ever re-use an old engine.