{HEAD ~ A working piston} reciprocates in {TAIL ~ one cylinder} and is conventionally attached to a crankshaft by means of a connecting rod and crankpin 
reciprocates in
{ HEAD ~ A working piston } reciprocates in { TAIL ~ one cylinder } and is conventionally attached to a crankshaft by means of a connecting rod and crankpin
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH