Well, I couldnt get a 15-8 prop today, but got a 14-8 just to try. The good news is: It spins it @ 8400 rpm, the bad news is: its a 14-8 [&o] Im not sure if it will be enough power for the plane i want to put it in. I might make a setup so i can measure thrust. I personally belive that its the amount of thrust produced that will determine how the plane will fly. (Pitch speed also plays a factor, but i dont think as much) Im going to order a 15-8 and see what numbers i will get. I might ask a few club members if they would donate a prop just for testing.
If i dont get at least 7700 on a 15-8, then i will start to do more porting. I also need to get a new muffler, cause the one i have, has a crack in it which is causing oil to get all over the engine. (at first i thought the case gasket was leaking) Im also going to order a frank bowman ring cause compression is still low.