Although a DR1 tri-plane can use lots of nose weight, I think the TechnoPower 9 cylinder would be way too much.........too large an engine for a 1/5 scale DR1. I scratch built a 1/5 scale DR1 from Tony Lunt plans (talk about a major project), and the cowl was less than 8" in diameter............much too small for a 9" diameter TechnoPower radial. My 1/5 scale DR1 flew well with a 70 4-stroke.

I think that engine would be better in a 1/4 scale project (maybe even bigger). You also have lots more choices and planes closer to scale outlines when you go 1/4 scale than the small variety in the 1/5 scale range. I'm currently working on a Flair 1/4 scale DR1 which has a 10" diameter cowl which would contain the TechnoPower engine. Flair makes a very nice kit of the DR1, and I could recommend it. Other 1/4 scale DR1s include: Balsa USAs, Arizona Model Products, and the ultimate DR1 kit from Glen Torrance Models, which is probably the most accurate.

Having said all that, if I had a TechnoPower 9 cylinder, I wouldn't want to put it under a cowl. I'd be looking at a 1/4 scale Stearman, or something similar with the engine out in the open for that project. The TechnoPower engines look a lot more like the WWII era radial engines than the rotary engines of WWI.