In a preferred example, the engine has a spark plug access well centrally located at {HEAD ~ the top} of {TAIL ~ each cylinder} 
of
In a preferred example , the engine has a spark plug access well centrally located at { HEAD ~ the top } of { TAIL ~ each cylinder }
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