Is it possible to have a 8.5T 540S motor with a KV rating of over 6000?
 

I got the specs from a vendor.

It is a 36 x 50mm motor by the way.

Sure you can. I have a 7T which is 8500kv. Graupner has 8T Delta wind at 7900kv and a 9T Delta wind at 7100kv.

The length of the rotor assy and the length of the windings have an effect on kv. So you can have 2 different length 8.5t motors and the shorter will have a higher kv, but less torque and potentially less overall power capability.

Actually, the question was: is it possible to have a 8.5T 540s motor with over 8000kv. Yes, a 540s can, but the turn count also determines the kv. There might be some leeway in kv by making slight adjustments to coil length, magnet quality/strength/proximity, etc, but generally, for a given coil length and diameter kv will be about the same for any motor.

Hey Thanks for all your replies.

Most of the 8.5T 540S motors out there have around 4000KV. I thought the vendor made a mistake or something.

And oh i did notice that the ecpower motor has a rotor diameter of 12.5mm. Somehow I feel that this motor has very a low torque as compared to other similar sized/kv motor with fewer turns.

Actually you might be surprise to find that the newer smaller diameter rotors have a stronger magnetic field than the older ones.
The LRP are a good example. The x11 came with 14mm. The Stock x11 versions come with 12.3mm rotors, but are stronger then the 14mm. Sor torque feels the same and it spools up quicker.

http://www.ecpower.com.hk/index.php?...roducts_id=267

Seems like the vendor made a mistake. I found the ecspeed 8.5T motor listed on ecpower's website as a 4000 KV motor.

Yes it's very possible, just use Delta winding (most 540s are using Y winding), and/or use a thinner rotor.