Here it is....All you could ask about inlet trumpets.
Never place bug screens on a bell. Very bad on the flow bench. A big bell cut off at the 90 degree angle and grafted to a flat plate is great and takes up less space. As in my Mazda racer.
Notice some monster engines trade runner length for bell diameter. I think runner length is less important than bell shape. The Vena Contracta plate shows why you need a bell shape.
I have plans for a flow bench that is more accurate than a Super Flow. Build in a day. Cheap. Make you very smart. Free if I can find that memory stick............
Lynn E. Hanover