I think that with transfers, we should definitely be careful not to hog things out too much in the interest of maintaining transfer velocity. If velocity drops too much, fuel doesn't stay atomized well. Flow is obviously good too, but only to that point where displacement and case volume/compression can adequately support it. I have no idea how to calculate case volume to make an informed decision on how much or even if the transfers would benefit from being enlarged. So I'll stay tuned for more folks to chime in on that subject.
One thing I have an idea on is this: I think in my mind that most saws would probably benefit from matching the lowers to the case (talking about cylinders with lowers like a 346, 357, 372 here) but I'm not sure if it would always work to significantly enlarge them all the way up through to the port windows themselves. I think of it like creating something of a venturi effect as the transfer tunnel comes around to the transfer port window itself. Low restriction from the case to the lowers and as they taper down I would think that might accelerate the transfer charge as it reaches the transfer window. We gain area by raising them if we do so, but so far on my saws I have ported I stopped at just raising them and did not widen them at all. I could very well be off in my thinking on this theory, but my saws came out well doing it that way.
