Moped Army

So the higher case pressure can send transfer mixture out the exhaust unless of course the relection wave from the pipe is strong enough by design to push the mixture back into the cylinder before the exhaust port closes.

A better solution is to use this extra available energy to your advantage. Lets assume your reflection wave isn't strong enough and mixture is escaping out the exhaust. What we need to do is use up some of the case pressure before the transfers open so that when they do, pressure isn't really any higher then if it wasn't stuffed.

We do this by running only one ring (the top) then putting ring land ports around it inside the upper ring land (someone post a pick). Some case pressure is bled off before the transfers open. This flow purges exhaust residuals from the ring pack and piston clearance volume so it can be sent out the exhaust on every stroke. In the process this flow effectively cools the piston sides all the way to the crown. You can then tune a more powerful, leaner mixture without worry of seizure. And lastly, the extra flow threw the ring pack is like adding some transfer window area, but without all the port timing compromises. I've got before and after dyno sheets if your interested.