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