Running without a thermostat ok?

As a stop gap and also a bit of a test...... Do you have the heater in the car? Just turn that on with the blower on high and it ought to take a fair amount of heat out of the engine. Of course, open the vent doors for yourself!

And perhaps this is a subject for a separate thread in the heating and cooling subforum......But, would you mind posting a pix of, or describing your fan mounting? There looks to be a rash of electric fans being mounted on flat, solid plates that block all the air through the rad except for a single large hole through which the fan pulls air. These are a good recipe for poor heat extraction at highway speeds.