I do what Darin Morgan does...spray from about 2ft. away, about 2ft higher than the intake port opening, and shoot for 1 second. Yes it does get into the bore adapter, just clean with solvent and let dry before flowing again. It works in helping to see where the heavier fluid is going, or taken by the air and also what it shears off of. Because there were so many changes needed (IMO) to the port, I used this more as a how bad is it really compared to how I normally size-shape a port. I was really surprised! The dykem test is as valid as dry flow numbers from a flow bench...you have to understand much more of what is going on than just numbers or how the dykem looks.
