Ed - yeah, I'll be updating the thread as I make progress. I'll put it back together dead stock and make "before" videos, so that the "after" videos have a little meaning. Hopefully.

Jim - The port areas are going to be tough to calculate properly because as you see, the bottom of the piston actually defines the bottom of the port. I can give the width and I can measure the piston travel before the port is covered, and that should be sufficient.

Sadly in this design there is no "short side radius" to be had - obviously I can't modify the piston, though that would definitely increase flow it would also kill the pinch.

I believe the defining limitation to the boost port is going to be the hole in the piston and how much meat I want to remove from that. The one side of the hole encroaches into the pin boss area, so carving away at that willy-nilly can weaken the piston significantly. We'll see what happens.

The transfer ports have a slight bevel to the edges, pointing the flow towards the boost port, but yes I intend to widen the transfer port towards the boost port and modify the flow channel in the case to suit.

One thing I noticed after I posted the pictures is the burn pattern on the top of the piston: at the edge of the piston right near the exhaust port there is a moderate brown stain that is also faintly showing in the middle of the piston, but on the sides where the three intake ports are the piston is clean. It's pretty clear where the fuel is washing the piston down... In the full-size engine world, one would read this to mean that you've got fuel separation at these clean areas and the burn is all happening near the dark areas, and you'd start reshaping the combustion chamber to try to eliminate flow separation. Clearly there's nothing to be done about it in this engine.

Oh, and I should also mention: this engine has about .010" squish clearance, but I haven't looked closely at the button to see what it's shaped like. I know the center is hemispherical but I don't know if there's a conical or spherical shape to the squish band. The piston is dead flat.

Ranger - you're the only one who keeps mentioning Winnipeg...