cooling problems

[flatjack9]

Geez, all this blather when it is obviously air flow through the radiator. It cools on the road, but at slow speeds it doesn't. Duh!

 

[supereal]

One of the reasons radiator shops have mostly disappeared is the boiling and rodding did not restore the efficiency. Due to the design, which sends exhaust down thru the water jacket in the flatheads, the cooling system needs the best radiator condition. Replacement radiators are expensive, so it is usually the last resort, but will do wonders. The original units were made to just handle the job, with little reserve. Any crud at all will render them sub par.

 

[37fordtruckguy]

Thanks for all of the help so far. I am going to make the switch to 160 stats and hopefully find a fan shroud that will work.

 

[gmc1941]

One of the best advises I could recommend is to use a fan shroud. By using one you can ensure the air is being directly pulled through the radiator. 30-40% of the air can by pass the radiator. Take a smoke device and place it by the fender apron and watch how much air is sucked in and around. After doing that I was amassed with by passing air.

 

[Kahuna]

Get the correct size radiator

 

[billwill]

your raditor is to small goodluck

 

[Bill S]

I have seen electric fans wired the wrong way and it was blowing out.

 

[expavr]

Get the correct size radiator

Amen. According to the 1940 sales manual the V8 60 core thickness is 1.75" vs 2.25" for 85 HP V 8's. The frontal area for both is 384 square inches. Assuming that the radiator in your truck is an OEM V8 60 core you are lacking one row of tubes which is about a 25% reduction in cooling capacity.
The fact that you are using an electric fan may not be enough to offset that loss of capacity in the radiator. Regarding the electric fan what is its size (CFM's) and how is it configured (Puller or Pusher)? As a frame of reference I'm using a shrouded 3500CFM puller fan to cool a 400 CI supercharged engine. That fan is thermostatically controlled to go on at 185* and will drop the coolant temperature 10* within a minute. It may be that your fan is undersized or is improperly configured and is not drawing enough air through the core at slow vehicle speed. Also keep in mind that even though the water pumps are new the coolant flow through the radiator will be slower when driving in traffic.