An internal combustion engine is provided having a pair of {HEAD ~ cylinders} interconnected by {TAIL ~ means} of a narrow connecting channel 
interconnected by
An internal combustion engine is provided having a pair of { HEAD ~ cylinders } interconnected by { TAIL ~ means } of a narrow connecting channel
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH