ramcram

What about a simple 12V fan in the stock alternator breather hose, or on the end of it under the headlamp, with a solid state temp sensor/switch fixed to the alternator housing. When the alternator reaches the set temp, the fan is turned on, runs until the temp drops by 10C and turns off.
http://www.ebay.com.au/itm/THERMAL-S...item417561f70f

Alan

Or take the rectifiers and regulator out of the alternator case, put them somewhere cooler (drivers front fender?) and cool those directly with a fan that is on the whole time you are running. At that point the alternator's built in case fan should be able to cool the remaining rotor, stator, slip rings and bearings much much better. Most of the heat (by far) dissipated in the alternator comes from the rectifiers.

You do need to modify the primary supply wiring to connect to the new rectifier output and also run the 3 high current phase wires from the alternator to the rectifiers and the 2 rotor field slip ring wires to the regulator. Lots of troublesome work to do it - but ultimately it would be a very very effective solution I think. The exact opposite of simple though.

Alan

j.kenzie@sbcglobal.net

Right now I am using a simple 12 volt marine bilge blower and a 3" duct in the standard duct location. It is on at all times the car is running, and cools the rear section of the alternator. I like that thermal switch, might consider adding it.
Thanks,
Dave

Alan

I wouldn't change it - there isn't really a time when cooling with ambient air with a fan like this will hurt - given the configuration and power dissipated I don't think you will ever overcool it.

Alan