HI Greg, sorry Have not got back to you earlier, still lurking as to what engine I am going to put in this baby, WEll I want to put a & cylinder radial, I found one that will fit Siedel St7-35 (35cc)that measures 7.6 inches which will fit scale like in the 8 1/2 to 9 inch cowl. But here is my concern, it will spin a prop from 18 X 6, 18 X 8, and even a 20 X 5, got a feeling the 18 X 8 is the best one for it, specs are around 5500 rpm weighing in around 2.6 lbs 1.5 kw of power which is alittle over 2 hp. Is this engine enough to put this plane in the air and fly scale. the next one up is a 7 cylinder ST7-70 (70cc) but measures 9.25 inches in diamter and weights about 5.9 lbs, 4 hp of power at 6300 rpm, is ths engine too much power and weight also?

I need to make a decision very soon
Also I will add pics of the plane soon as I am still catching up from the holidays
Paul
here is a pic of the ST7-35 and the ST7-70