GoolRC 3665 4Poles 3100KV Brushless Motor for RC Car Boat 3665 4Poles 3100KV Brushless Motor for RC Car Boat. Low heat production, long lifetime, strong overload protection and it can function 95% of its features without any heat sink appliance. 4Poles design, high torque & high efficiency. The overall efficiency exceed 90 percent. high quality materials adopted: high intense aluminum alloy anodizing shell , front & back cover. high-performance temperature-resistant magnetic steel and imported high-speed bearing.