Motor temperatures

[V6Jim]

I expect there'll be a thread somewhere discussing this, but I couldn't find anything.

I'm just returning to the sport(?) and ahve done loads of research and have been asking lots of questions.... However, at no point has the subject of motor temperatures been discussed.

What is too hot? What is not hot enough?

Jimmy

[john333]

Not really sure there is a "not hot enough" figure lol, but physically 100 deg is classed as overheating in most speedo manuals etc.

Think the hottest I've had a 4wd is 64 deg, and 2wd only about 45.

Some cars run their motors a bit hotter (dex410 for example in my experience)

[nites]

hi, I dont know whats normal but I regularly get up to 86 degrees c with a 4wd running aan lrp x12 8.5 indoors.
I know the x12's are regarded as a hot running motor though and have never had any problems from it.

Nites

[V6Jim]

I realise that most folks will use a digital thermometer, but would one of these be a good idea?

http://www.ebay.co.uk/itm/Factory-Effex-Temperature-Guage-Graphics-Decals-Stickers-3-Pack-NEW-/380483288647?pt=Motorcycles_Parts_Accessories&hash=item5896923e47

Jimmy

[nites]

hi Jim
I would think for that price you would be able to get a temperature gun off the bay. mine is a HPI gun and works fine, easy to use and small too, I wouldnt really bother except its left over from doing nitro. 86 degrees on the lrp means I can barely touch it so anything under that is fine in my eyes.

[mattr]

Probably not too bad, depending on how long they last. On a race car they'd probably be changed semi regularly. So it'd never be an issue.
Also, you'll struggle to get them to stick to an ESC........(heat sink cooling fins)
Don't know how much they like being bent or crushed either (the single use tabs we have at work have to be almost flat to work properly)

And a digital gauge is only about 20 dollars anyway.

FWIW, i usually only get up to about 80 degC (4WD) and 60 odd (2WD) so most of the gauge is useless anyway........

(except when i had a stiff 2wd transmission, hit 130 then, and promptly melted the rotor.)

[CrashBangWallop]

When brushless was in its infancy Novak used to give temperatures as 'the' way to correctly select your gear ratio and it used to be 130 degF which is around 55 degC.
I still use this guide today as it seems to still ring true because if you start overtemping your motor several things start to happen, the grease in the motor bearings starts to migrate and break down and also the copper windings which are covered in shellac or synthetic insulation also start to break down, cause a short and go up in smoke !

Although this was in the days when motor timing was fixed, these days with timing on the fly, boost and turbo motor temps do have to be managed more carefully - this means heatsinks & fans or it will go pop !

Use of a temp sensor is a good idea, much better than, Ouch thats hot or that smells a bit !