when should the auxillary oil thermostat open?

I have a 79 SC that I believe has been running a little hot during the summer months.
After about a 45 min. drive yesterday I reached up underneith my car to feel the oil lines that run parallel with the rocker panel. Niether line was even remotely warm. However,the section behind the Aux. thermostat was hot. The car was running at normal temps (little over 1/4 on the guage) in 65 degree weather.

My question is, when should this thermostat open? If I knew I could figure out if it is malfunctioning or not. On a very hot summer day after an hour or so on the interstate I can hear a gurgling sound comming from the front wheel well. This leads me to believe that it does work, I'm just thinking that maybe it should open up sooner.
Any thoughts?

------------------
Leland Pate

___79 SC Targa

It contains what appears to be the same thermostat 'mechanism' as the engine-block thermostat, and Bruce Anderson says you can test those by putting in a saucepan on a stove in oil and heating to 180-190 and observing to see if opening! So, if yours isn't allowing flow at a gauge reading that is 'normal' and presumably above 180 F, it most likely needs to be disassembled and cleaned, then tested and put back in service or replaced.

------------------
Warren Hall
1973 911S Targa