a thanks to all !, it's all good info, and thanks for the links Joe ! I will look into them,
for sure I will go with the Ignition on my Saito 100T (when I find the correct plane for that engine), with an Ignition I'm betting it will produce pretty much the same power (or more) on 15% as it would with a Glow Plug burning 20% ,,
too add, I would like to try an O.B.G. unit on at least one engine, just to try it, now what engine to pick LOL
Jim