The dimples have two purposes in my opinion. 1.) The dimples promote better mixing of the fuel/air mixture. This promptsore complete combustion. 2.) Like the surface of a golf ball the dimples will thin the naturally occurring aor boundary layer between the port walls and the transient (not laminar) air flow. The thinner boundary layer effectively enlarges the port increasing its flow potential.I wonder how the builder was able to machine such a symmetric pattern within the port...
