An engine 14 wherein {TAIL ~ said timing means} is adjustable to vary {HEAD ~ the compression ratio} up to 40:1 
An engine 14 wherein { TAIL ~ said timing means } is adjustable to vary { HEAD ~ the compression ratio } up to 40:1
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH