motor temp experiment
I am sure someone has already done this but thought I would post my findings. slash 4x4 stock size trenchers stock vilenion system with heat sink on motor no fan stock spur 13T pinion. I bash in dirt only. Using an infra red temp gun i try to keep motor temps 175 or less. I have noticed when I first start to run the truck when i check temps it doesn't take long for them to come back to ambient temp (i have no access to cooling fans). Then after a while it takes FOREVER for temps to come down. Here is what i found. The heat sink on motor becomes super saturated in heat meaning it will no longer pull heat out of the motor. So I thought what if I pulled heat sink and got it to ambient temp and reinstalled it? My motor temps came down twice as fast. I would just repeat the process of removing heat sink reinstall it for a minute or two to absorb heat then remove it again to cool it and reinstall it. I usually pack a cooler with water so the next time I removed the saturated heat sink threw it in the cooler for a bit and repeated and temps were ambient in no time. I think the motor heat sink is a good idea but once it is super saturated with heat from the motor it hurts cooling because it holds heat to the motor can wich slows cooling. Hope this helps someone.
sounds like to me youre over-thinking it.
first things first, in order for a heatsink to work properly it needs something to make a better connection to the component its pulling heat out of. they call this heatsink compound. i learned this when my xbox got the red ring of death, and in that case, we're talking about much higher temps but still the same principal. its basically a paste that helps heat transfer through 2 components.
a heatsink is a piece of metal, temp's dont "super-saturate" as far as im aware. the only thing keeping a heatsink from cooling is lack of airflow. think of it as a radiator on your car, you wouldnt drain your hot coolant, stick your radiator in a cooler and put the hot coolant back in...no, youd put a fan in front it. sorry in advance if any of this sounds blunt, but you need a fan, plain and simple. either a motor/esc fan or just a basic hand held fan you see kids play with (you know, small, battery powered, some even mist water)
make sure you buy some compound, coat the inside of the heatsink and clip it on, wipe the excess out and you should be good for a very long time. i still had some silver compound left over from my xbox repair so i used it and still have some left over...the silver is the most expensive but i think its only 10-15 bucks.
my temps have never gotten over 170 at my local track, and i run no fan or even a vented body.
Last edited by supradrew; 10-14-2012 at 05:19 PM.