In an engine structured to introduce fresh air and {TAIL ~ an EGR gas} into a cylinder, the EGR gas is introduced into the cylinder at least at {HEAD ~ a part} of a compression stroke using a pressure in a combustion chamber at least at a part of a power stroke 
In an engine structured to introduce fresh air and { TAIL ~ an EGR gas } into a cylinder , the EGR gas is introduced into the cylinder at least at { HEAD ~ a part } of a compression stroke using a pressure in a combustion chamber at least at a part of a power stroke
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH