Tuner has referenced NACA TR 49 in the past: https://www.abbottaerospace.com/downloa ... rburetors/ That's one I've downloaded today after seeing Tuner's recent comments on Speed-Talk.com, so I don't know the contents at this time.
Also, two air bleed / emulsion research papers from Japanese research efforts in the '60s which I've found helpful. I know the first one was also referenced by Tuner in another thread somewhere years ago:
"Effects of Air-Bleed Systems on Carburettor Performance"
Overview: https://www.jstage.jst.go.jp/article/js ... 1/_article
Download: https://www.jstage.jst.go.jp/article/js ... f/-char/en
It turns out there is also a "sequel" of sort, although I haven't found a copy that's been translated into English. Even though it's still in Japanese, I have figured out most of - possibly all - the key diagrams, but haven’t documented it anywhere at this point.
"Effects of Multihole Air-Bleed Systems on Carburettor Performance"
Yasuke ASANO, Ichiro ISOBE
Overview: https://www.jstage.jst.go.jp/article/ki ... 6/_article
Download: https://www.jstage.jst.go.jp/article/ki ... f/-char/en
I suspect people look at the publication dates of these and jump to the conclusion that they're no longer relevant. However, IIRC, the laws of physics and behavior of air & fluid flow haven't changed with the calendar, only the ease in which the data can be captured and analyzed.
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This is likely a "stickie" candidate, FWIW