wherein {HEAD ~ the slide valve} is a rotary slide valve of which a rotor is formed by the crankcase and a stator is a ring housing, wherein the crankshaft is stationary in {TAIL ~ operation}, 
wherein { HEAD ~ the slide valve } is a rotary slide valve of which a rotor is formed by the crankcase and a stator is a ring housing , wherein the crankshaft is stationary in { TAIL ~ operation } ,
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH