Wanted to field peoples opinions on an idea someone had. pls keep in mind that i only heard this and in some ways the theory makes sense, and im not going to do this to my head.

'Smaller ports are better' idea being it increases the velocity and atomises the fuel better. To some extent for higher hp, but not for boosted apps. the reason this makes sense is the wind shear between the wall and the middle of the flow will be greater and therefore mist the fuel better (it also increases resistance with the extra friction associated with the shear)

thoughts?

Its true. you'll find newer cars now have choking points just above the valve seats or the short side radius (floor of port). just think of how efficient your respiratory system is. close your mouth and inhale air as fast as you can through your nostrils. notice how quickly your lungs fills up?
they apply the same principles on motorbikes as well. basicaly the ports replicates the narrow section of your bodies intake system.

Similar to the idea of longer intake runners, higher velocity and more torque in low rev ranges, but less power and less torque up high. its all about the right tuned length and/or diameter for what you want..

Im sure that AU onwards have smaller ports than the e-series, but they probably countered it through gains with Dual cams and VCT... and probably gained that fuel economy you speak of...

thats more tuned length runners or trumpets you speak of there. but yes, another simple scavinging system

actually the au does have slightly smaller ports..
the ports are not quite as round as e series and they kind of have a flat bottom..