Re: This may belong in BR??
This was done years ago, way back in the very early 1950's, in two stroke engines, by an Italian named "Marcellina". There were more than one size engine built built by Austrian manufacturer Puch, a 125, a 175 and a 250 cc. It is called a Marcellina spit single design, and it ain't new.
This one is just an extension of that first design, with poppet valves instead of ports in the cylinder walls.
It, like the Puch engines, won't be a spectacular performer.