Such variables characterizing {TAIL ~ the combustion} in the combustion chamber are already recorded in {HEAD ~ modern internal combustion engines} 
Such variables characterizing { TAIL ~ the combustion } in the combustion chamber are already recorded in { HEAD ~ modern internal combustion engines }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD