Does increasing diameter or motor length help reduce cooling?

[gearhd48]

I was wondering if lets say going from a 36x50 can to a 36x74 can help reduce running temps? this also goes from going from a 36x50 to lets say a 40x50 can. let me rephrase that, does increasing diameter or length help cooling?

[kfxguy]

Well theoretically it should. A larger motor should strain less to push the same load. This is my thought process anyway. One reason I always over motor my setups.

[RayR]

Yes it will help motor temps. It is all about watts. The larger the can the more mass is present to absorb and dissipate heat.

[T.S.Davis]

Not to mention a large rotor should provide more torque. Meaning that it can turn the same size prop without working as hard to do it.

In theory. Motors vary of course.

[gearhd48]

Thanks guys!! After reading a lot of these forms I had a gut feeling it would, even though I never found it stated. Happy boating ya'll

[gearhd48]

Hey Ray....it's all about watts? I don't know watt your talking about! LOL

[petej]

My Zonda/Phantasm has the stock SSS 3674 2000kv motors. The port motor is cool, but the starboard motor is always too hot to touch. I tested the cooling water path from exhaust port to rudder intake and both sides flow equally. I'm a bit baffled, considering putting Leopard 4074 or 4082 2000kv motors in. Would these larger motors run cooler because they are more capable of the load?

[tlandauer]

Is the timing set correctly? Double check that the timing is the same as the cooler motor.

Sent from my D6708 using Tapatalk

[petej]

Both Seaking 120A ESC's were configured to the default timing value of 15 deg. I set both ESC down to 11.75 degrees and will see if that helps the starboard motor next weekend.
Would or does counter rotation cause a motor to work harder?

[Fluid]

With twins the inside motor will run hotter, assuming all turns are in the same direction. If one motor is a LOT hotter than the other, then probably:

1 - the hot motor is less efficient, damaged, or has a different Kv
2 - the boat is slowing down a lot for tight turns

It takes the same amount of output power (watts) to spin a particular prop a certain rpm. The prop has the same load and doesn't know what motor is spinning it. One motor may have a higher efficiency than another, so it will waste fewer watts as heat and thus would run cooler than a less efficient motor. As stated a heavier motor may run cooler simply because it has more mass to store that heat.

I've done quite a bit of actual testing of water cooling FE motors. OTOH lots of folks have opinions of what does or does not happen.



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