I'm glad you figured out how to get some air into the car during that low-speed crawl! A lot of other car makes of the 444/544 style had cowl vents you could open for fresh air. Our hood latch takes up that space, so we're stuck with trying to figure out how to duct some cooler air into the cabin.

I'm using the brake duct fan becasue my regular heater fan is dead adn I hven't found a replacement for it.

If your heater fan works OK and you can shut off the hot water flow to the heater core, you get the same cooling effect - provided you have your air intake duct in place so you aren't sucking up hot engine air.

As far as the engine getting hot at a low speed crawl, remember that the satock Volvo gauge is pessimistic; it shows the engine as 'hot' long before the water temp reaches the boiling pont.

I live in the desert where 110 degrees is a normal daytime temperature. We also have many stop-sign-controlled intersections, so I get to sit in traffic for several minutes at a time each block or so...not the greatest for keeping the engine temps down!

I swapped my old 4-blade Vovlo fan for a 6-blade flex fan, and I no longer have an overheating problem, although I have yet to drive the car over the Sierra Nevada mauntains. I'm slowly working towards building a fan shroud to maximize the airflow.

Congratulations on getting our car to run comfortably in a parade; those are far tougher on the car than most people realize.

BTW: In my last parade in June, I won 1st place - and I didn't even know we were being judged!