RE: What engine for this plane??? 1/2 scale project!!
DA 150, 3W 150/157, 3W 200, 3W 212 4 cyl., or a ZDZ 160/210 will get the job done just fine. On the smaller motors you will want to run tuned pipes. I'm putting a 3W 200 with canister exhaust on my Exclusiv Modellbau Pitts Challenger, once it's done.
Tom