John,
I have a ton of time on the RCGF 20, as well as the DLE 20. Under a cowl, it's very difficult to tell the difference between them.They turn identical rpms one engine vs. the other (OK, plus or minus 100 rpm one day vs. the next if you're into splitting hairs) and they handle identical. For sport use, they both love 16x8 and 17x6 props, with some guys actually using 18x6. Guys wanting to get up into triple digits with a sleek light plane might go 15x10 (Great Planes 70" Revolver). I would be concerned about over revving the engine with a 15x8. Turning these little guys much over about 8500 on the ground not a good plan if you want a happy engine that will last you a while. Regarding break in, I ran a tank full through it sloppy rich to rinse it out and get it fully lubed. The next tank it dialed in easily, so up in the air it went. Been flying 3 seasons now in my "go to" plane, without incident. I love the engine, and from what I've seen here, it's very popular among other owners as well. Has the same "over achiever" performance attributes the DLE 20 has become known for, and it's just as easy to handle. A "keeper" for sure! -Al
Last edited by ahicks; 07-25-2014 at 03:24 AM.