Actually putting in a bigger motor will always make it fly faster.... or at least provide the ability to fly faster if it is proped right.

Other factors may make it an ugly airplane to fly and one that'll snap roll out of a sharp turn but more power always means faster if it's used right. The provisos are needed because in this age of brushless motors that have widely varying Kv values it's possible to swap a small motor with a high Kv value for a much larger and more powerful motor with a low Kv that just won't spin the right sort of prop the right way to actually let the model fly faster.


..... life was a lot easier when we just used glow engines......

Getting back to the model that started all this I don't think there's anything at all to be gained by clipping the wings. This is already a small model. Look at the size of the blades of grass it's sitting on. Playing with the prop and motor and possibly adding another cell to the pack is all that is needed. A higher Kv motor that'll spin that prop with about 1.5 to 2 times the current and not melt down is going to make that Cessna hum like a Mustang. That's all that's needed in this case.

Granted it's a relatively dirty design for speed but the biggest gains for this thing are going to be the power system options. To make any significant gains in the model design it'll be neccessary to move on and pick out a racey style of model like a Speed 400 class racer or a smaller hotliner glider and motor those up appropriately.