I will be starting my build of a 42% Challenger II by the end of December, looking at doing the Bulldog II scheme. I aim to keep it around 30lbs, the mfg recommends a 100cc engine, wingspans is 86.6" and a length of 88.6". I want this one to be more capable of 3D flight than my normal scale builds, I need to have some fun thrashing about.
So my question is what cc, brand, and where in the states to get it?
A 100cc engine on something like this would probably be marginal in performance. If it were me, 3W all the way. A 110 would be sweet. Plenty of ponies... and at 6.72 pounds, it'd be pretty tough to beat the 12.8 horse and wide variety of props it would spin.
http://www.aircraftinternational.co.../RtnTab/228/PageIndex/1/CatID/86/Default.aspx
Or maybe if a 150 size will fit, like Terry suggested and I absolutely agree, how about the 3dub 157. At 8.66 pounds and nearly 18 horse, there wouldn't be anything you could not do with that plane. I absolutely love mine in my 260. (And she weighs 42 pounds) No such thing as too much power.
http://www.aircraftinternational.co.../RtnTab/228/PageIndex/1/CatID/86/Default.aspx
There is also the option of a 120cc power plant. DA makes a solid 120cc motor. But would be concerned with balance issues. 4.95 pounds.
http://www.desertaircraft.com/products/da-120?gclid=CMrt-PuYzskCFUuTfgodWvMCDw
Or the DLE 120. At 6.13 total pounds, it might be easier to get that bipe to balance. Pretty much the same props as the DA but considerably less in price.
There is also the GP123 and from what I have been hearing (and) seeing first hand, they are a beast of a motor. At just over 5 pounds and swings about the same size props as the DA and DLE, but with massive authority. Dave Sullivan is one of the nicest guys you will ever talk to. You can also give
@SupaTim a call. He and
@Spats can give you all the awesome details on this motor.
http://northwestrc.com/GP-Engines_c_24.html
There is also the option of a ZDZ 112B2 twin. Though I have no experience with this particular motor, I hear they run superbly. And
@Flyrcjoe is probably one of the most knowledgeable people on this motor you can talk to.
http://zdzusa.com/shop-2/zdz-112b2rv-j-champion/
Those are the options I myself would look at in doing this plane. I myself would probably look very seriously at the 3w 110. But that is just me and my liking.