The apparatus includes a combustion chamber communicating with {HEAD ~ an air intake passage} and {TAIL ~ an air exhaust passage} 
The apparatus includes a combustion chamber communicating with { HEAD ~ an air intake passage } and { TAIL ~ an air exhaust passage }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL