Originally Posted by DP-buggyboy

Cool! I didn't do much last night - hopefully I'll be more motivated tonight.

I thought about the need to maintain port velocity too. I'll likely end up changing the shape of the ports depending on how it works. The good thing about the prototype design I have is I can easily change the port shape, size, overlap, and timing by swapping out the upper valve seat (which is basically just a flat piece of steel with holes in it).

I even had thoughts of a guillotine-style power valve arrangement to vary the size of the ports depending on RPM. It wouldn't actually be all that hard to do, BUT it probably won't happen since the motto of all good RC engines is KISS... I guess I'll file that one under the "Anything is possible" category for later on.