Hot to replace piston

Which side should grove face to intake or exhaust

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0

crwdns2947414:01crwdne2947414:0:

@ahmedali46293 what groove? The marking on the piston rod? You need to be a bit more specific.

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

crwdns2934285:0crwdne2934285:0