I am working on a modified version of the Webster - hopefully I will do a write up and pictures soon. But for the moment, I am pondering a question. Due to only having low-quality 1mm drill bits on hand, I was having trouble drilling the hole through the stem as per the original Webster design: Having trashed one of the valves, I had to remake at least one anyway, so I went ahead and remade both using a different design, one that I have seen in some of the engine plans here and elsewhere, thus avoiding drilling the itty-bitty hole: Here's the question: is either design inherently stronger / better than the other? Note that the valve stems for the Webster are 0.094" diameter; the through hole in the first design in .040" diameter; the groove in the second design is .008" deep by .040" wide. At first I was thinking the first design takes more "meat" out of the valve stem ... but then I decided maybe not, or maybe the round hole offers some strength advantages over the rectangular groove, or ?? FWIW, I successfully completed the second design, and it all fits together nicely, so this is more a question for the future ... but meanwhile I got in a pack of 1mm carbide drills that I ordered, and was easily able to drill a beautiful .040" hole through a test piece, so if the first is really way better than the second, I could go ahead and make another valve and go with that design. That would only make about the tenth time I have re-made these teensy-tiny-stinking valves ... what's one or two or ten more?