I don't know why I did it but then ... why not??  the other day, I finally completed a rat racer I started back about 9 or 10 years ago.  Today was the first flight  .  After having flown Q-500 r/c for a number of years with good success, I had a spare Rossi 40 sitting in the cabinet doing nothing so I decided to see what would happen if I sort'a resized a copy of a Scat Rat     I had to redo the spacing for the engine and lengthen the fuselage about 3" inches to hopefully compensate for the weight of the Rossi 40 and muffler.  I left the wing the same span at 24" and slightly increased the size of the horizontal stab and elevator .... why??  I dun'no !!  Seemed like the right thing to do  .  Anyway, I had a buddy grab the handle so I could get some video with my Go-Pro camera and time the flight for a few laps.  Well, I let it go on the rich side using an APC 8x8 prop.  I'm pleased with that we saw and I'm looking forward to the next flight with the needle tweaked about 1/4 turn and an APC 9x7 or 9x8 prop   

   Thanks for the kind advice.  Yeah, over the passage of time since I last flew Q-500, I had forgotten just how "sweet" and yet intimidating the Rossi 40 sounds    .  I took it out for the initial flight this weekend and had the engine a bit on the rich side when I launched it.  I had my buddy fly it so I could video and time it.  The flight seemed smooth and he said there were no adverse handling issues.  Seems like the average speed was 88 - 89 mph.  Next time, we'll tweak the needle about a 1/4 turn leaner and bump it up from 5% to 10% nitro  .