Here is an awesome video series on YouTube explaining flow characteristics of ports from rotary housings over the years, and the effects of porting to change flow and intake timing.
Charts, graphs and castings made by an engineer. I found his explanation on the runners helpful, and how oversizing can rob power.

So far they've been viewed only a few hundred times (less than 300).

I'm trying to link to the first of three videos in this series. If the link doesn't work, search for "Rotor V Piston - Rotary Port Evolution" by SidneyCritic ComedyHound.


Enjoy!

 

Great find. Pt 2 with the port molds is especially informative!
Youtube's algorithm sucks, I'm looking at rotary videos all the time and this hasn't come up.

 

that is really cool. i've seen the molds and the graphs before, but the explanation in the video really makes it useful

 

watched all three. i've seen molds made before, but no one ever broke it down across the years in a comparison. i found the whole thing fascinating and learned some new things.

thanks for posting it.

 

One more.

"Rotor V Piston - Rotary Bridge Port Flow Development"

Not all Bridge Ports are the same.

He flow tested various bridge port designs to see which had better flow and which changes reduced performance.
You might want to tear apart your engine to make corrections after this. -wiink-

 

mistakenly bumped this thread, but there are actually 5 or so total videos total on youtube for this