Since most inline engines don't have much of a short side radius to begin with, the intake and exhaust ports enter/exit the head at a straight in shot, the lumps actually create a better radius to direct the airflow into the bowl area. If you did a cross section cut on a V8 head, you would see that the intake port tapers as it gets closer to the valve, creating a short side radius that is real desirable for enhancing the flow thru the port. What the late Kay Sissell did when he developed the "lump" port technology, was create or duplicate, this same tapering of the port to form a short side radius that was comparable to what most V engines already had benefit of. Now, instead of spending hours heating and brazing, and grinding, and then more heating and more brazing, you can just install a bolt-in "lump" that will give similar results for far less $$$$'s. As for the techniques used by others that have made claims of hitting water when only cutting the seats for 1.94" valves, the experience card could be part of it, but it was probably due to other underlying issues like a badly core shifted head casting, or maybe a crack that was undetected prior to beginning this procedure.
