Something coooool

[Brod]

I did something similar on a nitro heli conversion a few yrs back.
The Mega motor ran gasping hot before i did the fan job.It then ran cool.
I put 2 12v fans back to back wired in series,which made air flow stronger.
I eventually changed to a Kontronic Tango motor which has an internal fan which ran stone cold.

[Steven Vaccaro]

Cool idea Jeff. What about a small fan and a some thick shrink wrap. You can probably just shrink it on the end of the motor.

But if enough heat is being generated that we need both air and water cooling, shouldn't we also consider moving to a different size or wind motor? The heat is being generated from wasted energy not friction, wasted energy means a slower boat. For example, if you do succeed in cooling a motor from 160 to 120f, the efficiency is still a problem, you've just did a better job in keeping the motor from self destructing. Just something to ponder.

[ozzie-crawl]

i thing i wonder is when a person says there motor is getting a bit hot if its being pushed to hard or just heat soak.
when playing with a data logger awhile back i spent a bit of time looking at heat
i found on acouple of my setups that temps would rise to a certain temperature and fairly much stay there like a petrol engine getting to operating temp
but once the boat stops temps can jump rather fast as the motor/esc heat soak and have no cooling happening
by the time a boat is emoved from the water hatch removed and temps taken there can be a 20 deg diffrence

[Jeff Wohlt]

These are evercool fans.

I like the idea, Steve, but The round part on the motor keeps a flow pulling better and the fan does not sit on the motor. This creates a better pull thru the motor. I think shrink might work but something solid like this keeps that air pulling since the air is channeled from the round part. It may work but I wanted something stronger. The fan is a good 20-30 mmm from the back plate so the draw seems like it would be better creating more air flow.

Beats me...still playing. I like the fact that it can cool the internals down quickly so you can get back out in the water.

[Steven Vaccaro]

i thing i wonder is when a person says there motor is getting a bit hot if its being pushed to hard or just heat soak.
when playing with a data logger awhile back i spent a bit of time looking at heat
i found on acouple of my setups that temps would rise to a certain temperature and fairly much stay there like a petrol engine getting to operating temp
but once the boat stops temps can jump rather fast as the motor/esc heat soak and have no cooling happening
by the time a boat is emoved from the water hatch removed and temps taken there can be a 20 deg diffrence

Good thoughts and info. I never played with the temp feature of the logger. I always figured it was just as easy to whip out the temp gun at the end. But now you've given me reason for changing that thought.

[Rumdog]

i thing i wonder is when a person says there motor is getting a bit hot if its being pushed to hard or just heat soak.
when playing with a data logger awhile back i spent a bit of time looking at heat
i found on acouple of my setups that temps would rise to a certain temperature and fairly much stay there like a petrol engine getting to operating temp
but once the boat stops temps can jump rather fast as the motor/esc heat soak and have no cooling happening
by the time a boat is emoved from the water hatch removed and temps taken there can be a 20 deg diffrence

Wow, I've never even thought of that, yet it makes perfect sense!

[sailr]

It seems to me that a fan is just going to recirculate hot air inside the boat. Doesn't seem very efficient to me?

[Steven Vaccaro]

It seems to me that a fan is just going to recirculate hot air inside the boat. Doesn't seem very efficient to me?

Yes, but dont forget the hull is in contact with cold water, the inside of the hull wont be as hot as the inside of the water. So there will be some cooling effect.

[Drag Boat Bob]

It seems to me that a fan is just going to recirculate hot air inside the boat. Doesn't seem very efficient to me?

Don’t underestimate the cooling power of a fan.

My car stereo amp would repeatedly hit the thermal shut down due to being in a very small enclosed trunk (sports car). Being a black car would cause the area to heat up quickly in the sun, so the ambient was already pretty warm. I added one small fan to blow across the unit and have had no problems since.

[Jeff Wohlt]

Air is better than no air. Yes, air thru a motor will certainly make a difference.

Do you know how many IC motors are air cooled? The heat only builds as the motor begins getting hot...cooling the motor early so it does not reach the high temps keeps the air cooler as well....does that make sense?

[ozzie-crawl]

It seems to me that a fan is just going to recirculate hot air inside the boat. Doesn't seem very efficient to me?

put your self in a small sealed room when its hot and your body heat makes the room hotter, now turn a fan on, the fan is only pushing air that is already in the room but you keep much cooler and the room stays much cooler
same thing in a boat hull.

[sailr]

Very interesting points all! I have some small fans, guess I might try one on a non-water cooled ESC and see how it goes.

[egneg]

put your self in a small sealed room when its hot and your body heat makes the room hotter, now turn a fan on, the fan is only pushing air that is already in the room but you keep much cooler and the room stays much cooler
same thing in a boat hull.

Not the same thing ... wind chill only affects rhings that have moisture to give to the atmosphere. Evaporation takes heat away from things much faster. The room itself is not any cooler, actually the heat given off from the fan motor makes it hotter.

[Rumdog]

Running 3-4 minutes, do you think it is enough time to heat up the cabin in your boat? I'm really not sure. I know that Jay "Fluid" Says that a fan can really keep the temps down, I remember seeing pics of a fan in his sprintcat with a 1527. Ya gotta figure, the bigger thehull, the better air cooling with a fan is going to work. I am a cnc machinist. Every motor that my machines have, some being swiss type lathes with multiple motors have fan cooling. They are just larger versions of the pc type fans, and they work reall well in confined spaces. I know it isn't the same application, but moving air into the motor has got to have some sort of cooling affect.

[egneg]

The fan does redistribute the heat and you are probably correct in saying that for short runs in a confined hull it will help to keep the motor from reaching critical temps.