Hey there, Kris -

OH... I know your EXACT feeling! I went back & forth forever about which engine to use. After having great success with a Saito .72 on another plane, I am a huge Saito fan. After reading all through those HUGE UCD threads and reading all the engine choices, I found a lot of satisfaction with those running the Saito 100s with either a 15x6 or 16x4W APC prop. Lots of others too, but these were the most listed.

SO! I'm putting a Satio 100 in mine, and like another fellow did, I think I'm mounting mine at 90 degrees rather than inverted. Just like everything, there were some who were and some who were not experienceing "inverted engine issues". Some readjusted, some added pumps, some added regulators. I think I'm going 90 degrees and hopefully things will be as smooth as my .72 that I run upright in another plane.

Well, that's my choice and I hope it proves to be a winner... although I do like the sound of those 120/140 rockets.

-s