GDixon - I believe you are right, but for the wrong reason. A piston goes through the same stroke, regardless of RPM. (eg: it doesn't "go beyond" when given more throttle.) :)
OK, final rebuttal. <_<
The pistons under normal temperatures do indeed go through the same stroke unless the rod bearings are loose or worn. The pistons do not touch the cylinder wall but the rings do instead. My point, as was originally stated, involved the piston rings which have a built-in tolerance so that they will move in the lands regardless of the piston temperature. Metal does expand when heated as you probably know. That results in a bit of wobble which is even a bit more evident when the engine is cold since the design is for them to expand when warm. (The rings get larger and the land gets smaller since the walls of the piston heats up first along with the top.) It is also a fact that the connecting rods slightly lengthen when the engine runs hotter causing the stroke to be longer by enough to cause the rings to hit a pre-existing worn lip at the top of the stroke. That could cause ring damage in extreme cases.
Apologies accepted in advance.
BTW, if there is a better explanation, rather than sniping, let 'er rip. :)
You have to take into consideration that the materials used in the engine components have been taken into consideration during design phase. Expansion/Contraction #'s are well within tolerances for longevity of the toy/lex engines. Buy the car, Drive it any way you want, Maintain it within your driving habits.