Overheating - 440 Magnum 68 RT

[Dads68RT]

I could run the engine for about three minutes before temp gage starts going into the red. I felt the top of the radiator and it wasn't even warm so I took the thermostat out. Now I can run it for about 10 minutes. There's no shroud on the fan / radiator. The radiator is getting hot. I have antifreeze in it because I was in Maine for a few years.

Is it the lack of a shroud? Could the antifreeze/water mixture cause it to overheat? Or, could the water pump be bad? How would I know if it was a water pump?

[Mfr426]

Having a shroud makes a HUGE difference in the engine running cool. I would not run a car without out. Put a shroud in (still available from Mopar I believe) and then see how it runs.

Mike R in Reading PA
69 Charger Wedge 505

[mally69]

Make sure you dont have a small block radiator. There is a difference between a big block and small block radiator, not just the size itself but the core's inside are smaller.  What is the casting number on the top of the radiator.If I had that number I could tell you exactly what it is.  I run a 440 bored 60 over with just using a factory 440 fan with no shroud but I have a big radiator with an added core and i haven't any heating problems even on a 90 degree day.

[Blown70]

Having a shroud makes a HUGE difference in the engine running cool. I would not run a car without out. Put a shroud in (still available from Mopar I believe) and then see how it runs.

Mike R in Reading PA
69 Charger Wedge 505

Agree, I did this without then added one to my prior 69, FIXED 90% of the issue right there.

[craigandlynda]

MUST have a shroud, also 50/50 antifreeze raises boiling point to about 240 degrees...and the right fan is important...also, if this setup isn't original, be sure you have the right radiator, right fan, and pulleys, because the fan should be no more than about an inch from the radiator...btw, sounds like pump is fine.

[firefighter3931]

How old is the radiator ? has it been recored/reconditioned ? How old is the antifreeze mix ?

Your cooling system probably needs a good flush and perhaps the rad boiled out for peak performance. You can check for waterpump flow with the rad cap off....when you goose the throttle a bit the coolant should circulate faster than at idle. It sounds like the waterpump is working but the cooling system needs a little TLC.


Ron

[Dads68RT]

I'm sure there was a shroud on it before. Dad must have taken it off when he was working on the engine. I'll start looking for a shroud - shouldn't be too hard to find. Here's some pix of the radiator/fan. 2582942 is the # on the radiator.

[2Gunz]

According to this website 

http://www.rosevillemoparts.com/reference_radiatorguide.php?SID


That Radiator belongs in a 318.

[2Gunz]

Oh and before you go buying a stock Radiator, I would give this guy a try.



http://cgi.ebay.com/ebaymotors/ALL-ALUMINUM-1970-72-DODGE-CHARGER-PRO-RADIATOR-375AA_W0QQcmdZViewItemQQcategoryZ33602QQihZ012QQitemZ220261440716QQrdZ1QQsspagenameZWDVW


I purchased one for him..... and it makes a HUGE differance.

The term opens and 20 seconds later its closed again.

My car cruises at around 190 Deg in the California heat.


He doesnt have a "1969" charger radiator.

But I gave him sizes and what I got was a real close match.

Biggest trouble was I had to weld on a shroud support.... but for $200 bucks I cant complain.