The motor I was running in the Pitts was the recommended (and cheap) Turnigy SK3542. this motor seemed a pretty good match. on 3 cells spinning a 12x6 prop it pulled over 40 amps and over 500 watts.. not too shabby.
The problem i discovered with the Turnigy moto is the fragile shaft. After just clipping the prop on the deck during landing the shaft sheared. The shaft itself is only 4mm diameter and it has a groove for a retaining circlip, not too surprising that the shaft sheared across the circlip groove.
I decided to upgrade the motor. I went for a Scorpion SII 3020 1110kv. This has a much beefier 5mm shaft with no circlip groove, so hopefully no more bust shafts. Despite being only a few grams heavier the Scorpion motor is rated for a constant 60 amps rather than the Turnigy's 40A. Running a 12x7 prop on fresh battery I'm actually pulling a little over 60a static and a whopping 780 watts... so that's a 50% increase over the old motor
Might need top be carefull with the throttle as my ESC is only rated for 60a but I'm sure in flight it will unload, so should be ok.. expect fun