Tenshock Evo 2270 "High Power" Version (40mm x 99.5mm long) :

Evo TS-MI-EVO2270-HP High-Power version: 40x100mm: 6 Pole Motor.
-See picture 2 for motor chart. 

If you're building a 1/8-scale hydroplane to run in Namba 1/8th class, the Tenshock 2270 850kv motor is the hot setup. Widely favored in 1/8-scale hydroplane racing for its massive 6-pole torque, launch speed, and high cornering speeds. Pair this motor with a Castle Cobra for the ultimate package.

1. Powerful 6-pole core design for high torque output.
2. Advanced assembly technology enables more efficient space utilization.
3. CNC-machined aluminum casing
4. 5. Silver and copper wire alloy for super high efficiency over a basic copper alloy wire. 
5. Powerful sintered neodymium magnets
6. High torque-to-weight ratio.
7. The hand-wound weaving of the winding ensures the motor has excellent electrical characteristics! 
8. Includes a free water jacket with an internal water channel to ensure water flows around the motor 
9. High-grade bearings

Specs:
Magnets: neodymium
Watts: 8500
Poles: 6
Motor Shaft: 8mm
Shaft Length: 21.5mm
Can Measures: 40mm diameter x 99.5mm long
Weight: 580 Grams
Mounting Screw diameter required: 3mm
Bearing size: 8*19*6 (front), 5*14*5 (rear)
Connectors: Required - OSE suggests 8mm 
Water Jacket: 60mm long

OSE suggests 30,000-40,000 total rpm. These are only guidelines; if you don't know how to choose the correct motor, please consult OSE first or other members of the RC Fast electric boating community, either at a local club or on our OSE Forums. 

* It is important to note that the "Max Amps" value represents the maximum recommended operating current for the motor. It does not indicate the maximum current the motor can draw. For instance, the 1550kv motor has a "Max Amp" rating of 165. This means the motor should not be operated at a current exceeding 165 amps. However, this does not imply that a 180-amp ESC will be compatible with the motor. Instead, the user must select a propeller or gearing that prevents the motor from exceeding its "Max Amp" rating. It is important to note that the 165-amp motor can and will exceed the 165-amp range when pushed beyond its limits for a short period of time.