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