440 Cooling Problems

When you swap a 440 into your truck, you will need to increase the cooling capacity. The easiest way to do this is to install a 3 row core radiator. The other essential part is a fan shroud. The stock heavy duty water pump is adequate for almost all applications. The bearing in the heavy duty water pump is a lot bigger than the one used in 440's installed in cars.

Additional things you can do are:

1. Install a flex fan, preferably one with 6 or 7 stainless steel blades that clears the edges of the fan shroud by about ½" and spaced so the center of the fan blade tips meet the edge of the shroud. Alternatively, you can install a clutch fan, however I prefer the flex fan because it doesn't go bad and destroy the water pump.

2. Install the plastic shrouds that keep air from going around the radiator.

3. Install a 16 PSI radiator cap.

4. Use a 50% ethylene glycol antifreeze solution.

5. Add a can of Water Wetter to the antifreeze solution in the radiator.

6. Make sure neither of the radiator hoses are kinked and the lower hose has a spiral wire inside to keep it from collapsing.

7. Install a "problem solving thermostat" which Chrysler Corp offered to help with overheating problems on vans and motorhomes.

You can back off the timing a couple of degrees, which will also help with pinging. If you have an intake with an EGR valve that is working correctly, you can run a little more compression and slightly more aggressive timing. Keeping the radiator, air conditioning condenser, and transmission cooler clean and free from bugs is essential. Using a fine mesh screen in front of the radiator can either help or hurt, depending on how often you clean it.

Installing a thermostatically controlled electric fan in front of the radiator helps keep the temperature under control at idle, however you also need to make sure your alternator is up to the task of supplying enough current at low RPM.

I don't recommend turbo-charging the 440 even though aftermarket exhaust manifolds were offered that a turbo-charger could be bolted to.

You can also use type 3 heads, which have more coolant passages cast in. If you do, make sure the head gaskets don't block the extra passages.

Article written by Joe Leonard 3-07

Joe Leonard 2007-03-04