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