Hi, recently I finish a Pattern style model that should weight 2000g(70.5 Oz) with a glow engine. But instead, I put a Himax 3516-0840, a CC Phoenix 45 amp, APC-E 12x8 and a Hyperion VX 2100 11.1v.
With that setup the plane weight 1600g(56 Oz.), and it does all the pattern sequence without problems....I have 10 minutes of full power. This is because a plane that weight 70 Oz glow powered, doesn´t mean that should have the same weight with an electric motor. In fact I just prove that with an electric setup the plane weight 400g(15 Oz) less!!(particularly in this type of aircraft).

Hope this helps, Mato.