Notched-piston mod?
I read in some tuning guide somewhere on the internet that one "common" mod for nitro engines is to notch the piston where it overlaps with the boost port. The idea is this will supposedly create a smoother surface for the intake charge to flow over, and also increase the effective size of the boost port because the piston won't be blocking as much of it.
However, this mod would also allow the boost port to open earlier, since the edge of the piston that's supposed to cover the boost port will have been moved down. Taken to an extreme (i.e. if you notch the piston so far down that the entire boost port is uncovered at bottom-dead-center), you could cause the boost port to open at the same time as the exhaust port, or possibly even open before the exhaust port.
I can't think of any scenario where the engine's performance would be improved by opening the boost port before the excess exhaust pressure has had an opportunity to vent, because it seems like that trapped pressure would just stall the flow of intake charge up through the crankcase. However, perhaps there is something I'm missing, like...maybe that problem doesn't really exist, because the boost port won't just open earlier, it will also stay open later...or something like that. I honestly have no idea.
So I guess what I'm asking is:
1) Does notching the piston even slightly destroy its ability to form a good seal in the pinch zone? Or would it be okay as long as the piston is notched prior to break-in, so the wear-pattern inside the sleeve would match the shape of the notched piston?
2) What is the actual effect of changing the timing of the boost port such that it opens earlier and closes later? How would it affect the engine's torque at low RPM vs. at high RPM?
If you want to link me to a pre-written port-timing guide instead of typing answers to these questions, that's perfectly fine; I wouldn't mind reading a comprehensive guide, I just can't seem to find one. Pretty much everyone just says "leave it to the pros", and that's cool, but I still want to understand what the pros are doing.