What radiator/electric fan setup for 74 Dart 318?

[1mopar4life]

I have the factory V8 radiator and fan with shroud on my 74 Dart with a warmed over 318 in it and it doesnt over heat but does run very close to the edge. In heavy traffic it doesnt do very good at all and with summer coming up I am going to be installing A/C on it so the cooling demands will be even more. What options do I have for a bolt in radiator that will keep it running cool and what fan setup should I run? I plan to spend around $400-500 all said and done to keep my car running cool. I also want the thermostat to turn on the fans rather than having a switch but that will also depend on how much a setup like that runs.

 

[73SwingerBuild]

Don't quote me on this, but I'm fairly certain electric fan set-ups are less efficient than the stock fans are with the correct shroud. However, aluminum radiators are far more efficient than stock radiators. If you pick up an aluminum radiator with an electric fan set-up, the advantages of the aluminum radiator may outweigh any disadvantages associated with electric fans.

Either way, your current radiator is definitely not sized for A/C and the setup will certainly overheat the motor. What thermostat do you have in there now? Maybe try bumping down to a 160*F or 170*F?

I'm hoping a more knowledgable member has something to add here.

-Mike

 

[falston1]

I've got the same problem with my 360. I bought a stock replacement 360 A/C radiator when the original \6 radiator busted and it's still too small. One electric fan on the front of the rad plus the OE clutch mechanical fan and a 160* thermostat brought the temp down 5-10 degrees I read on one of the Big Block Tech threads that a 90s model ford f-150 radiator will work and is plenty big for a big block. It should do wonders for a small block. I'm planning on looking into it this summer. New mounts will have to be made, but it'd be a huge difference and cost a lot cheaper than buying an a-body aluminum piece if you dont mind looking for a good junkyard radiator.

 

[Bulldozer]

i bought a 2 core 26" radiator and fan shroud out of a 86 lebaron for $40. i have a solid mount factory 7 blade fan and a 180* thermostat. my fan is 1 1/2 inches away from the radiator, sitting in traffic for days the temp gauge barely reaches the half way mark. for me an electric fan and $300 radiator would be a waste of money and total overkill. i drilled two holes and it bolted right up. i literally have less than 60 bucks into it. my $0.02

 

[67Dart273]

..................... However, aluminum radiators are far more efficient than stock radiators.

There is some controversy as to whether this is actually true

It depends on the actual design of the radiator, as well as improved construction (brazing) methods in modern brass/ copper designs

http://flex-a-lite-blog.com/2010/03/30/radiators-aluminum-vs-brass/

http://www.hotrodhotline.com/md/html/aluminum_vs_copper.php

A short quote from the above article:

============================================================
"So what did U.S. Radiator learn? First and foremost, they discovered that where the radiator is concerned core design and NOT material had the greatest effect on temperature drop."
============================================================

There are many many factors in heat exhanger design besides the material. Tube shape, thickness, strength, and on and on.

AND REMEMBER THIS You cannot economically repair an aluminum radiator.

 

[BillGrissom]

Cheapest would be to keep your radiator and add a pusher electric fan in front. The fan from a Mercedes 300D is fairly easy to install and they are showing up in junkyards. I have one on my 64 Valiant and have one for my 65 Dart. Another popular one is the Ford 2-spd fan (forgot model, check rodder sites like HAMB). It is almost like an airplane propeller.

I don't know what you mean by control off the thermostat. Perhaps you mean off the "temperature gage". That would require very custom circuitry. Simplest is to install a separate temperature switch, but only a few PN's are set for ~190 F since most are for over-temp warning (~215 F). Wire so either the temp switch or the AC compressor turn on the fan relay, i.e. most people want the fan on whenever the compressor is running.

Don't install a 160 F thermostat. That won't lessen over-heating and will give poorer mileage on the highway and in winter. Indeed, I run a 195 F thermostat in my cars.

If you get an aluminum radiator, be sure to use the correct coolant. They corrode much easier than copper. Worst is if there are stray electrical currents flowing thru the radiator, so check your grounds. I hear that can corrode a hole in as little as 1 week.

 

[73SwingerBuild]

There is some controversy as to whether this is actually true

It depends on the actual design of the radiator, as well as improved construction (brazing) methods in modern brass/ copper designs

http://flex-a-lite-blog.com/2010/03/30/radiators-aluminum-vs-brass/

http://www.hotrodhotline.com/md/html/aluminum_vs_copper.php

A short quote from the above article:

============================================================
"So what did U.S. Radiator learn? First and foremost, they discovered that where the radiator is concerned core design and NOT material had the greatest effect on temperature drop."
============================================================

There are many many factors in heat exhanger design besides the material. Tube shape, thickness, strength, and on and on.

AND REMEMBER THIS You cannot economically repair an aluminum radiator.

You are correct. I mis-spoke. What I should have said is that, all thing being equal (i.e. same design of radiator), aluminum radiators will run cooler than stock-style radiators.

Also, the repairs are an issue. I'd rather have a 3-core stock-style radiator, but I got an aluminum one for free, so I'm running with it.