The intake/exhaust valve member is axially movable within {HEAD ~ the combustion chamber}, and operatively cooperates with {TAIL ~ wall structure} of the combustion chamber 
The intake / exhaust valve member is axially movable within { HEAD ~ the combustion chamber } , and operatively cooperates with { TAIL ~ wall structure } of the combustion chamber
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH