Overheating Issues, Perplexed

[elmariachi]

Originally Posted by Jamo

I live in Fresno...we'll match or exceed anything Houston or Florida thinks is hot or humid.

I think I can win that bet.

Originally Posted by Jamo

Other typical precautions, of course...burp and reburp the system to insure there are no air pockets, check the air flow, dump the undersized pulleys and get the thermostat down to 160...get the water flowing sooner (biblically-speaking, heat begats heat), timing, etc.

Given everything you've reported on...especially how the temp drops a bit when you give it some gas when it idles...I'd think about a bigger radiator, assuming no flow issues with the passages or pump.

I tried the 160*, made no difference. The engine will eventually surpass 160 and then 180, so the only purpose the t-stat is providing is to determine the running temp down the road. When I had a 190F in it, it ran 190 down the road. I have a 180 in it now and it runs 180* down the road.

Jamo, I assume you have the Fluidyne in your car? After looking at one in a local car this past weekend, there is no comparison between it and this PRC in my car. Though its 1.5" narrower, the Fluidyne is much thicker in the core and the tanks. So that's my ace in the hole. But I am going to start with the smaller water pump pulley, then play with the fans. I also borrowed a big honkin' shop fan that looks like a Pratt & Whitney radial engine and see what happens when I add it. Probably won't get to do all this until the weekend.

Originally Posted by 767Jockey

El, It should get better when you call more of the radiator into proper use. This seems to be the only change you've made that had any documentable difference to the problem. This is certainly the road I would go down. Best of luck.

I have no doubt that if I can locate a deep enough shroud that it will make a big difference. The difference in temps between where the fan is drawing air through the fins near the center and out near the corners where there is no draw is 20*F. So if a properly shrouded high cfm fan, coupled with a larger capacity radiator, added to a smaller water pump pulley doesn't do the trick, then I am moving to Colorado. I hate Houston, so I needed a good excuse anyway.

For those that asked, the 3600 cfm Zirgo fan I now have is showing 13.1 volts at the wiring entering the fan motor, versus 13.6 at the back of the alternator at idle.