Hacker A50-16 S motorshave a 4025 stator (weight 345g)and are more appropriatefora 50-size plane, like Sebart Angel 50or Sebart Wind 50.
see:
http://www.rcuniverse.com/forum/fb.asp?m=11427948
For a 90-size plane, with a 19 / 20 inch prop, probably something a little larger would be better.
The Turnigy SK3 5055 motors have a 4030 stator, and weigh 370g /380g. They give a little more power.
These SK3 motors are made alongside Hacker motors in the same Sunray factory, and are identical internally to Hacker motors
see:
http://www.rcgroups.com/forums/showp...postcount=4209
Next size up would be a Hacker A50-16 L -type motor -these weigh 430g, and use a 4035 stator.
There is no Turnigy SK3 direct equivalent to this A50-L -size motor.
However, this Hacker is exactlythe same motor, made in the same Sunray factory, as:Lipolice LP-4035 (Germany), HYPERION Z4035(e.g. Robotbirds) and BMI SPITZ 80 or BMI SPITZ 90 motor (also Germany). -The BMI SPITZ 90 is the exact same motor as aHacker A50-12 L V2, Kv 345, 12T motor See:
http://www.rcuniverse.com/forum/fb.asp?m=11450304
-Just choose the Kv you want, and then go for a Lipolice / Hyperion / BMI /Foxy /Turnigy SK3 /Gens Acewith that KV; They all come from the same factory...
see:
http://www.rcuniverse.com/forum/m_11426913/tm.htm
P.S. The person who runs BMI-Model in Germany, told me that: "... Spitz motors and controllers come from the same manufacturer as Hacker..".