Golf Balls have dimples which break up laminar flow, allowing a driven ball to fly farther.
http://wings.avkids.com/Book/Sports/instructor/golf-01.html
The Mythbusters applied the same effect to a car’s surface…and got measurable increase in mileage.
Automotive tuners often smooth out the passageways in and out of an engine, in a process commonly known as porting the head.
Can golfball-like increases in efficiency be achieved by applying dimples to the port walls?
They explain it pretty well in the other thread. No. The dimples cause airflow to adhere to a surface. That’s an efficient way to get an object to pass through air. But there’s no need to get the airflow to stick to the port walls. And the airflow will become very turbulent after the air leaves the port anyway. I could see this possible helping in the intake manifold or on the exposed surfaces of valves. I couldn’t get your 3rd link, maybe it’s showing the manifold and not the ports specifically. It might be helpful anywhere air has to change direction. But on a golf ball or car it’s preventing turbulence that interferes with a seperated airstream rejoining. There’s no airstream to rejoin in an airway like that. But if there was, it would be decreasing efficiency unless it was needed for a secondary effect like better fuel/air mixing.