Cylinder head lower wall 16 extends over and closes {TAIL ~ opening} 14 of each cylinder 12, while {HEAD ~ a piston upper portion} 18 closes an opening at the lower end of each cylinder 12 
Cylinder head lower wall 16 extends over and closes { TAIL ~ opening } 14 of each cylinder 12 , while { HEAD ~ a piston upper portion } 18 closes an opening at the lower end of each cylinder 12
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH