I am running a 355 chev with Edelbrock aluminum heads, an aluminum water pump, a PRC cross flow radiator and a pair of Spal fans set up as pullers. The thermostatic switch is set up to turn the fans on at 195º, and shut it down at around 175º. With this set up, it takes about 2-3 minutes idling for the temp to drop back to thermostat temp (180º). Problem may be my imagination, but on a nippy evening, the temp will bump 200º and come back down. and in traffic it cycles a lot. I think that it is running warmer than it should.
I have drilled a couple of small holes in my thermostat, and have attempted to "burp" the system. It never goes over 200, but I feel that it should not even get near 200º on a 65º night.
Anyone have any suggestions???