I've scanned a lot of old threads and have not seen this question. Sorry if I missed it.

25 years ago some rotary firms talked about modifying the Nikki for additional performance. Some modifications were for the very old IMSA RS class. Other were for the street. One of the things that was done was to press out the stock venturis and press in replacement larger diameter venturi.

Weber as an example have replacement venturis but the few that I have seen and use else where are the wrong length, outside diameter, inside diameter, etc

Does anyone know of a source and part # for a larger inside diameter venturi that will press into the Nikki primary and secondary respectively?

If not, for racing only, I can bore the inside out but I won't get a great shape. Has anyone done this? If so what diameter did you take the primary and secondary out to and what was the result?

Did you use a boring bar?

Did you have any problems?

FYI I have done the booster tabs, throttle shafts, air horns, butterfly screws on throttle shafts, tried venting float bowls, air and fuel changes, etc.