The 3650 and 3660 motors are among the most commonly used sizes for 1/8 and 1/10 scale RC cars. If you’re planning to upgrade your motor, understanding the differences between these two is essential. Let’s dive into a detailed comparison.
3650 vs. 3660 Motor
The numbers 3650 and 3660 refer to the size of the RC motor. For example, a 3650 motor has a diameter of 36mm and a length of 50mm. When under load, the larger 3660 motor offers higher RPM and torque.
Useful Knowledge: You might notice that some smaller motors have a higher KV rating, meaning they spin faster when unloaded. However, under load, the speed also depends on torque. That’s why larger RC cars often use motors with greater torque, even if their KV rating is lower.
Which is Better?
Which motor is better, the 3650 or the 3660? It really depends on your RC car—what’s best is what fits your needs. Generally, the 3660 performs better on rough terrain. However, there’s a lot more to consider before making a choice, such as size, weight, voltage, and power consumption. For those new to the RC hobby, it’s an funny challenge to figure out what works best. But don’t worry, we’ll break it all down for you next.
Motor Installation Guide
Shaft Diameter: The shaft diameter of the 3650 and 3660 motors often differs, with the 3650 typically having a 3.17mm shaft and the 3660 having a 5mm shaft. For 1/10 and 1/12 scale cars, a 3.175mm or 3.15mm shaft is common, while 1/8 scale cars usually use a 5mm shaft.
Pinion and Spur: The shaft diameter needs to match the bore of the pinion gear. If it doesn’t, you’ll need to either replace the pinion gear or use a shaft adapter. Additionally, you’ll want to pair the motor with the optimal gear ratio, which depends on your driving style and terrain. Finding the best gear ratio requires some trial and error, and be sure to monitor motor temperature to prevent overheating. Tip: Consider adding a heatsink or fan.
Motor Size: Check if your chassis has enough space to accommodate the motor and if the screw spacing matches your motor mount.
Weight: There’s typically a weight difference of around 100g between these motors. If you’re preparing for a race, weight balance is crucial as it affects stability during speed runs, especially when cornering.
Voltage and Power Consumption: The motor’s voltage determines the number of LiPo cells it can support. The 3660 motor also draws more power, so you’ll need a higher-capacity battery to extend run time, as well as an ESC that can handle the increased current. Otherwise, your equipment may overheat and get damaged.
