engine size takes a look at various things....wing span, weight, wing loading, and intended use (trainer or sport etc)......
trainers are great....they, along with an instructor teach the student to fly....because trainers aren't speed demons, are forgiving of mistakes, and are tough.......
now you go and put a bigger engine on a trainer...the airplane weighs more, wing loading is more, the basic airplane has not changed.....you get some more speed and more vertical...but it is still a trainer....it still flies like a trainer.......lets be honest...kinda hard to knief edge a trainer the length of the runway.
let trainer be trainers when you are ready to move on, go to a different kind of airplane so your learning can continue.....</p>