Engine Fan Positioning And Airflow

I dealt with this same problem, several years ago. Tried several things including a radiator cleaning. Finally going to a larger capacity radiator solved my problem. No more wild temperature fluctuations.

 

And for an easy, at least partial fix, throw in a bottle of water wetter. I use the Redline stuff. Everything else equal, it's good for about a 5 degree drop.

https://www.redlineoil.com/waterwetter

I had a similar issue with the 381 sbc in my 3B. The cure was an aluminum radiator-two row 19x26-the previous radiator being a 4 row Modine bass version the same dimensions, FlowKooler 1880 high flow water pump, fixed 6 blade 19" steel fan with no clutch (Flex-a-lite) , and my custom home built aluminum shroud that has very little air leakage around the perimeter and a relatively snug fit to the fan. I have a hood scoop of sorts but the area of that opening pales compared to what can blow out from beneath the Willys. I also wrapped the headers to a point just past their exit from the fenders and a large engine oil cooler (sits below the radiator and is also serviced by that shroud). And the water wetter. It all worked very well. Except maybe if you are sitting in deep fine dust. You can create your own cloud sitting still there.

 

X2 on this.
I have seen many race engines that would overheat without Waterwetter.

 

Nice metal work.

 

We had a hydrostatic self propelled haybine that we used water wetter in. Darn chaff would clog the screen and it'ld get hot. It had a 225 slant 6 and the hydrostatic cooler was in front of the radiator. The water wetter did the trick at least until the governor caught fire...

 

Google “FlowKooler” water pumps for example. They have them for the AMC V8, the 232/258 sixes, or even Dauntless V6.
There are other companies also. I have used CAT in the past with good results. I don’t know if they’re still around.
-Donny

 

Did you do a through and full flush of the coolant system before that long life antifreeze went in there? Do you remember the exact brand and chemistry? And does "Dex Cool" ring a bell? Because that cooling looks pretty orange/tan.

 

Yes, pulled thermostat, disconnected lower radiator hose and disconnected heater hose. Flushed until water ran clear and then s'more.

Prestone. Pale, translucent green. Not the premix.

Definitely not the orange Dex Cool.