RE: Goldberg Sukhoi engine
The 3250 would be way too heavy. My Webra 1.20 weighs 26 oz, one of the lightest engines of that size. I could roll into knife edge on takeoff, clearing the wing tip by a couple of inches and climb on out in knife edge. It had enough power to do knife edge loops, though it ate up a lot of sky doing it. The only weakness of the kit was the landing gear plate would not hold up to the 1000's of touch and go's that I did with it. This was one of the early kits with the landing gear mounted to the wing. I doubled the number of wing ribs and doubled the width of all the kit ribs to increase glue surface area to solve it.
This is a nice flying sport model and took the abuse in the air quite well. (Actually better than the Webra did, as it chewed up the rear bearing after the first 110 flights.) Second Webra was in the plane when the Sullivan fuel system leaked half a tank of fuel out and the airplane ran out of fuel 15 foot off the deck during a snap roll. Zero airspeed, no engine, 12 foot drop with wings level. Broke fuselage in half, and damaged all the fiberglass parts. Still needs rebuilding.
Put the ST2350 on it, add the Jett Turbo-Jett in cowl tuned muffler and you will have a rocketship.