What is the purpose of this?
 

Hey Folks, one of the PO has installed a heater hose that runs from the radiator area, thru the engine compartment and down the frame rail. The other end isn't connected to anything and just hangs off the frame rail almost like a drain. Any idea what its purpose is for? I appreciate the help!

Maybe some kind of spray bar for the radiator?

Now that is a good guess I think....Hook up some water into the line and see if it drips, or mists in front of the radiator. Could have been for extra cooling?

After looking at it that was the First thing that came to mind spray bar :)

Well i took a turkey baster and forced some water into it and sure enough it acts like a drip bar running the water down about four areas on the radiator. A PO must of had to have a way to force water into this while driving. Makes me wonder how much better it would cool the motor down.

Sounds like a water misting or drip system to me. My dad setup a similar system on his '86 F-350 6.9L with a rubbermaid tote with a lid in the bed. It was working well pulling our 33ft. Tailgator up the 395 to Mammoth until heat from the exhaust manifold melted the hose [laugh].

I'm thinking that might not work so swell around here. You can drive a couple hundred miles and not touch pavement.

Any idea how much water you would need to put through it to do much good?

1 quart a minute would cool about 130,000 BTU/hour, assuming water at about 80° evaporating in contact with the radiator.

That's significant, and 15 gallons would cool it for an hour at that rate.