If raise the cylinder that much to get the piston flush (which is really not important, unless with piston at TDC the skirt opens the exhaust port to the crankcase), the exhaust and transfers will be raised considerably.

And then the bottom of the transfers will be well above the piston at BDC. Modern bikes aren't that way either.

My guess is if you raised the cylinder that much and machined the deck to get squish clearance, you'd end up with a engine that had terrible power characteristics and less power than stock. (Might even lose the top fin in the machining)

Bite the bullet and send the cylinder and head to Rich... and get a new carb... which might mean a new air filter system... and then find someone to build you a good pipe.

Or just leave it alone and run it.

Amen.

Think what is still coming in and out of the cylinder at BDC!
Nothing important, just back and forth flow in/out. What is important for "supercharge effect" from pipe is to stuff the fresh charge lost to the pipe, back into the cylinder just before E.C. point.

cliff

Just to stir the pot--not seriously though--Automan can sort me--with the step at bdc would or could that upset the wave affect from stuffing the fuel back in with the return pulse. Sorry, read again, takes affect just before exhaust closes. Was trying to think what EC meant haha, got it now. I read a bit--can read lol, so pipe cone & overall length determines at what revs this stuffing all takes place for best affect & desired revs??. Thanks.

Reading back i see in post #6 you ported it to MX specs so pipe design is important if you're making a chamber.

RT, ramming lost fuel/air back in at BDC would run into a blockage upstream.
No net flow.

cliff