I was told that if my question was about motors and ESCs than it would be okay to put it on here even though it has to do with an RC car...

I am wanting to do a brushless upgrade for my WLTOYS 12428 RC car... I looked on ebay, but all of the ones that say that they are compatible with my RC car, are a lot more expensive (between 10 to 30 dollars more) than others (most say that they are compatible with the WLTOYS 144001 RC car.

What makes a brushless motor upgrade compatible?

Here are the package list of two products: one that says it's compatible with my car, and another one that doesn't

Compatible with 12428 Compatible with 144001
120A Brushless ESC 120A Brushless ESC
Brushless Motor1 Brushless Motor2
2.4G 3CH Remote Control 2.4G 3CH Remote Control
Metal Steering Servo Metal Steering Servo
Metal Rocker Arm Metal Rocker Arm
Heat Sink -

Would this be compatible? They pretty much have the same thing (with the same specs), isn't that all that matters?
I could just buy a heat sink separate, they are too expensive... though, if the brushless motor has an aluminum heat sink casing, would I need a separate heat sink?

1 From the pictures on the listing, we can see that it is a 4300KV brushless motor
2 The pictures from the listing don't show an more details on the motor, should see if it is a 4300KV motor?


2 Answers 2


The important points are:

  1. The physical size. One of these is labelled 'BL3650', which probably means that the can is 36mm diameter and 50mm long. Of course, it doesn't have to be exactly the same size, just fit in the car.

  2. Output shaft diameter - so it fits your gear.

  3. Mounting bolt pattern, size and spacing.

  4. The Kv, or speed constant, which sets how fast the motor will turn at a given voltage. This doesn't have to be exactly the same but should be within about 10%.

These are usually all specified when you buy a motor on its own, but when you buy a plug-in replacement they often don't bother to list them. If it's not listed, there's a fair chance that motors for the same size car will match the first 3 points, as cars used to use industry standard brushed motors.

If there's no Kv listed, you could compare the cars they're designed for. If the cars look like they drive at a similar speed, have similar sized wheels and gear ratios, the motors are probably a similar speed.

  • 1
    $\begingroup$ Wow amazing answer, this is probably the best answer that I have ever seen on any Stack Exchange website, thank you so much! I will take a look, and hopefully save some money... 😁 $\endgroup$ Jul 15, 2021 at 16:18

Robin Bennett's answer, is very good, but I just wanted to post this as well just in case there is someone having a similar dilemma.

I ordered the cheaper one (the one that said it was for the 144001 car). The motor fit fine, the gear as well. The only problems were with the switch (which may not be any different with the one that said it was for my car...) and the steering servo (it was too small, the screw holes couldn't go in the spots on the car chassis).

After I saw that it wouldn't work, I looked up the part specific to my car, and found one even cheaper than the one that I got. So my suggestion to anyone who is in this same dilemma, either wait until you find a cheaper one or just go for the cheapest you can find.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.