Did someone once ask about the valve arrangement on a rotary engine?
The Monosoupape had transfer ports from the crankcase, ( very vaguely ) like a 2-stroke.
The earlier engines had a 'valve in piston' doodah.
It may not have been on this forum, but Norman ( Ah, bless him
) has sent me a pic. of the latter.
If it was not here, feel free to ignore me.
If it was here, you've got a piccy.