If it weighs 5lbs, I'm thinking you'll need at least 8lbs of thrust just to keep it glued to the tree without rising. so 10 -15lbs to make it advance. (and don't forget to add the weight of the engine at 10 - 15- lbs of thrust, you're talking about a big engine!)
Thanks Minnflyer.
This is where I was headed when I said .40 to .46 intsead of .049 for a .37 pound vehicle.
We've all heard, and used the "TLAR" principle (That Looks About Right) with RC planes. Well, my mind just won't come up with anything TLAR for this project.
Honestly Ralph, I'd like to see you suceed with this, beacause I've never seen nor heard of anything like it. But you mentioned wasting too much money, and I think everything you throw at this will be "wasted". EXCEPT, for the fun you'll have trying and learning!
My best for your success!
Dennis-
Oh, by the way, I've never seen a 4 blade pusher prop, not sure there is such a beast.