I googled to try and find what I originally read about it, but no luck. At the time, I had included "Dodge" in googling, since I have a Ram 50 truck. Anyway, a while back I turned up a cylinder polish/port article written about a Dodge 2.2 engine -- I think it was the one in the old Neon? This guy uses a die-grinder to carve parallel grooves in the intake manifold in front of the port transition area, which, like you might figure, disrupts the laminar airflow and tumbles the mixture into the cylinder. Made sense to me -- moreso than just polishing the surface to increase flow and count on piston dome or other surface to make turbulence. This was turbulence specifically, not "swirl". Also, you only need to do one surface of the basically 4-sided intake port -- this guy had done some analysis that showed how the airflow follows the channel and sticks to one side.
Here's another wrinkle: he filled the upper valve chamber (the stem recess) with epoxy (not totally, but at least half) to increase velocity -- and volumetric efficiency (I assume). I forget what he did to prevent stem binding on the epoxy, but it was an interesting idea.
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