I did it with a Norvel 074 which pulls nice with a 7*3 . It is better on the glow fuel than a 10 or 15 and I was able to get powered flights of 8 to 10 minutes on the 2 oz tank.

It was a two channel glider and I added a servo near the back of the canopy to take over the exsisting elevator and rewired one of the front servos to run the throttle. This was a two meter sailplane from the house of balsa.
Good luck.

I gave mine away to a friend so he could get hooked in our hobby.

Eric