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