Over Heating

[MOXY100]

I'm wondering if anybody knows whats the right size radiator for a 68 RT, 440, engine is built and is a 70.  Engine runs great, in Spring and Fall but come Summer, it over heats sitting at a light.  The size in the car now is 18 3/4" x 27 5/8' x 1 1/4"  any help would be appreciated, thanks, Moxy

[doctor4766]

You'd want a 26" right?

Check out this thread if you haven't already
http://www.dodgecharger.com/forum/index.php/topic,60599.0.html

[bobs66440]

Are you running a fan shroud? If it runs cool at speed but overheats sitting still, chances are it's because there's not enough air being pulled through the radiator and that's where a shroud comes in. At speed there's lots of air and the fan does little or nothing. Pretty much all your cooling is from the moving air. The fan (and shroud) take effect at slow speeds.

The fan should be half in/half out of the shroud opening for optimum cooling.

As far as I know, there are two size (width) radiators available for your car...22" and 26". It sounds like you already have the 26". Just for reference, I am also running a 440 (basically stock) with a 22" and it runs cool regardless of the outside temp.

If you don't have a shroud, that's the first thing I would try. Then move to other things like a possible issue with the water pump or maybe a partially clogged radiator. Also the timing may be too retarded...

[resq302]

Automatic or stick?  Axle package or not?  Also, do you have a direct drive fan or clutch type fan with or without a shroud?  Have you changed the coolant lately?  If so, the system may need to be burped.  Easy way to fix this is to run the car with the front end raised, like on ramps, and run with the rad cap off.

[MOXY100]

Thanks for the insight, yes it has a shroud, and is a 4 speed, haven't changed coolant, but will start with that, thanks again, Moxy...

[Dans 68]

...Have you changed the coolant lately?  If so, the system may need to be burped.  Easy way to fix this is to run the car with the front end raised, like on ramps, and run with the rad cap off.

Or do it like i did when I put the original 22" radiator back on the 383 4-speed. Leave the radiator cap off, and the front end slightly lower than the back (blame the driveway), start it up and walk into the house. Guaranteed to belch coolant all over the car and engine.     After I cleaned it up and refilled the radiator it ran like a champ to MATS and back.

Dan

[FLG]

Did you happent to put a 440source wp housing in it? 

[W4ATL]

Overheating at a light most likely means your fan is not pulling enough air through the radiator. Make sure the fan clutch is good. If it spins to easy when warm then you need to replace it.

http://www.dodgecharger.com/forum/index.php/topic,68196.0.html

[bobs66440]

Overheating at a light most likely means your fan is not pulling enough air through the radiator. Make sure the fan clutch is good. If it spins to easy when warm then you need to replace it.

http://www.dodgecharger.com/forum/index.php/topic,68196.0.html