I got a bird that I am trying to finish up and a need a bit of advice.

The wing span is 51.5"
Length (firewall to rudder TE) is 44.5"
Root Span is 15"
Tip Span is 13.75"
Wing is 2.75" thick (made of all 2mm)

With everything in/on it except trim colors, engine and tail wheel this thing is weighing in at about 4lbs 110z. and I was looking at putting a GMS .47 on it.

Will a GMS .47 (with tuned muffler) pull this bird pretty decently? If not, the next engine I have is a GMS .76.

I built this to be a sport plane/fun fly but with 3D (I hope) capability and I am looking for suggestions as to whether the GMS .47 or .76 to pull it. Unfortunately, I don't have an engine in between any more.

Based on the provided info, what do ya'll think?

Thanks,

Crash Master,
I think the GMS .47 should pull it around with no problem. I have a spad now 48" WS 38" Long 12" chord with a .40 Magnum XL
weighing just under 6 lbs. It pulls it around the sky with no problem. It will even hover for a few seconds
before falling out of it. As soon as I get some photos I'll post them in a separate thread.

I'm not really a good enough 3D pilot to predict whether your plane will fly decent 3D, but it appears that it will be more than a pound heavier than a typical 48" span 3D plane, like the OMP Edge, plus a bit less wing area which will increase the wing loading even more. My guess is that's it's too heavy with the .47 for decent 3D, at least compared to wood planes designed for 3D.

Sorry, I don't really want to rain on your parade. The "Spad way" is to give it a try, there's really nothing to lose.

Your plane weighs 4 lb 11 oz without engine and tail wheel. So it will weigh ~ 6 lbs RTF. For 3d performance with a .47 engine, the plane should weigh less than 5 lbs, 4lbs is great. I have a 60 size trainer that weighs about 6 lbs and an OS 46 BB flies it fine but it won't come close to 3d. I now have the 46 on a Burrito at 4 lbs - much better. I would use the 76.