Not too long after I flew my Dynam Corsair with the stock power setup I placed an order for the upgraded 650kv Detrum motor from Grayson. The stock 500kv motor was ok, but there was little headroom in the power department and I found myself flying around at about 70% throttle. A 4-bladed prop helped out quite a bit, but I just couldn't resist the temptation to upgrade the motor. Honestly, I think the 650kv motor should be the stock motor on this plane. I think Dynam went with the lower power output for flight time which is one thing I don't worry about with my 5200mah packs in the Corsair.
Why Detrum?
1) I knew the bolt pattern on the firewall would be the same.
2) I knew the prop shaft length would work without any modification.
3) Kept all other things equal: Same build, same magnets, same bearings etc..This enabled a direct power comparison with KV being the only change.
4) I knew the prop nut from the 500kv motor would work so I wouldn't have to hunt down another one for a different thread/pitch shaft such as what the SK3 motors use.
Bottom line: I wanted a direct replacement without spending time/money sourcing other parts to make everything fit. It also didn't hurt that Grayson had this motor in stock for only $25. Comparatively speaking, that seemed like a very good deal to me.
Initial bench tests look great. The stock Detrum 3720 500kv produced about 480w with the stock 3 blade prop. I installed a 4 blade prop from the Unique Model 1400mm Mustang and that got the wattage up to ~530w @ 32a. For the 650kv Detrum, I went back to the 3 blade Dynam prop and upgraded the ESC to a 60a Hobbywing Skywalker.
See the video for results. I was very pleasantly surprised at the power this motor makes with a 4s battery. Looking forward to flying this setup as soon as I can. I'll also probably order the same motor for my F6F Hellcat.
Bonus: With the Hobbywing ESC, no more low speed stutter.
Enjoy,
J