Cooling System Update for 64 Dart

-
chinze57

chinze57

Push Button tranny and a Slant 6 that'll never die
Joined
Nov 6, 2019
Messages
454
Reaction score
102
Location
Georgia, USA
I will be rebuilding my 225 Slant Six and will be increasing the power out of it (different cam, probably overbore, bigger exhaust, carb, etc).

In addition to that, i figured I’d improve my cooling system to prepare for added heat + a/c.

I’m interested in removing the belt fan. Yes it’s reliable, but it’s a power drain and it’s an inefficient waste at best while cruising at speed.

An aluminum radiator probably makes sense, so should I do 2 row or 3 row (or some other option I don’t know about)

What electric fan, shroud, controller, alternator, etc should I use? I daily drive this car so eliminating this hp draw and significantly improving my cooling ability at idle would be amazing. I understand not everyone on this forum loves electric fans, but not having it running at higher speeds (and when not needed) reduces parasitic loss, noise, and they can move lots of air.

I plan on adding either a classic auto air or vintage air system later on, so planning ahead for that cooling is also smart.

Thank you for any insight or advice
 
Let the electric vs. mechanical debate begin! :popcorn:

I prefer electric myself, so my 451 is cooled with a 3-row 26" aluminum radiator (there isn't room for a 2-tube), Ford Contour fans, and an Autocoolguy PWM controller. Works perfectly and maintains temp.

You won't need that much cooling for even a warmed-up 225 though...
 
DrCharles said:
Let the electric vs. mechanical debate begin! :popcorn:

I prefer electric myself, so my 451 is cooled with a 3-row 26" aluminum radiator (there isn't room for a 2-tube), Ford Contour fans, and an Autocoolguy PWM controller. Works perfectly and maintains temp.

You won't need that much cooling for even a warmed-up 225 though...
Click to expand...

Of course, I’ll never need as much cooling for a 225 unless I was running something like compound boost and doing heavy track days (which I’m not) but I’m planning on building a cooling system that’ll be able to handle more than what I plan on putting behind it.

I love seeing the electric vs. mechanical debate on these forums. I understand some people’s concerns, especially if you messed around with it 15 or more years ago, but it’s a different ballgame now, better components, more support, etc.
 
Just to be the devil's advocate, a fixed fan doesn't induce much parasitic loss when the car is at speed- the air is already moving so there isn't as much drag. It's basic, and about as dependable/reliable as you can get. Putting a shroud on it if you don't already have one is about all you need to do to cover anything your slant will ever throw at it. (In The Old Days Story: I once drove a slant about a hundred miles after I broke a fan belt. Never overheated. Highway speeds kept the fan/pump spinning fast enough to keep it cool.)
An electric fan also has parasitic loss when running due to the additional load on the alternator, especially if the fan is sized adequately; and then you may have to look at upsizing your alternator to handle the increased load, which means modifying the electrical system to safely handle the larger alternator...
But the electric has the advantage of running after shutdown if controlled properly, and being able to mount it as a pusher if clearances are limited...
I've run both, and each has it's pros and cons. The ballgame hasn't changed much, it's still a matter of adequate airflow. And it's debatable if the components are better or worse than 15 years ago- one word: China.
Why not just put a clutch drive fan on it if there's room with the slant? Least effort, best of both worlds.
 
Well, the OP did say that he wanted to overbuild the cooling system to handle anything he might want to do someday :)

I figured it would go without saying (apparently not) :rolleyes: that a stock Chrysler alternator from that era wouldn't have enough oomph, or big enough wiring. I designed my electrical system around a swapmeet CS-130 alternator that puts out well above the rated 105 amps (think it was 90-something even at idle). Including the wires. The Contour fans draw 40 amps with both on high speed.
 
Professor Fate said:
Just to be the devil's advocate, a fixed fan doesn't induce much parasitic loss when the car is at speed- the air is already moving so there isn't as much drag. It's basic, and about as dependable/reliable as you can get. Putting a shroud on it if you don't already have one is about all you need to do to cover anything your slant will ever throw at it. (In The Old Days Story: I once drove a slant about a hundred miles after I broke a fan belt. Never overheated. Highway speeds kept the fan/pump spinning fast enough to keep it cool.)
An electric fan also has parasitic loss when running due to the additional load on the alternator, especially if the fan is sized adequately; and then you may have to look at upsizing your alternator to handle the increased load, which means modifying the electrical system to safely handle the larger alternator...
But the electric has the advantage of running after shutdown if controlled properly, and being able to mount it as a pusher if clearances are limited...
I've run both, and each has it's pros and cons. The ballgame hasn't changed much, it's still a matter of adequate airflow. And it's debatable if the components are better or worse than 15 years ago- one word: China.
Why not just put a clutch drive fan on it if there's room with the slant? Least effort, best of both worlds.
Click to expand...

I mean, I get it. There’s parasitic loss with everything running off the crank, no matter what. Water pump, alternator, fan, A/C, hydraulic power steering.

At full output, a 130 amp alternator only consumes around 5 hp, whereas a mechanical fan/clutch fan uses 14 hp or so when engaged. So let’s say I run contour fans that, as another commenter said, uses 40 amps when running, that’s only 1.5 hp, only when running. That is far better in my book.

It’ll also allow me to run A/C in the car when needed and not Be drawing even more power off the crank.

And, like I said, I really want to overbuild the system.

DrCharles said:
Well, the OP did say that he wanted to overbuild the cooling system to handle anything he might want to do someday :)

I figured it would go without saying (apparently not) :rolleyes: that a stock Chrysler alternator from that era wouldn't have enough oomph, or big enough wiring. I designed my electrical system around a swapmeet CS-130 alternator that puts out well above the rated 105 amps (think it was 90-something even at idle). Including the wires. The Contour fans draw 40 amps with both on high speed.
Click to expand...

Absolutely, I’ll be improving this Ben charging system. I will be rewiring the car with a Ron Francis Express kit, and will likely step up my alternator to something that will output plenty to keep up at idle.

What fans/shroud are you using? Any pics or diagrams would be helpful
 
How much room is there from your water pump snout to the radiator? With a big-block it is very tight - other useful fans like the Chevy HHR won't fit. In fact the plastic on the fan shroud has to be trimmed a little to get any clearance at all. Here's a couple of snaps.
DSCF0175.JPG
DSCF0179.JPG

It's been many years since I owned a slant-6 A-body so I don't recall how long they are.
 
DrCharles said:
How much room is there from your water pump snout to the radiator? With a big-block it is very tight - other useful fans like the Chevy HHR won't fit. In fact the plastic on the fan shroud has to be trimmed a little to get any clearance at all. Here's a couple of snaps.View attachment 1715618141 View attachment 1715618142
It's been many years since I owned a slant-6 A-body so I don't recall how long they are.
Click to expand...


I’m revisiting this now that I have my new engine in. I have lots of space.
EC7AEE03-3311-46EA-965C-B2C8A155161B.jpeg

In this photo, the radiator isn’t in yet, but there will be more than an inch I believe between the front of the fan and the radiator. (I believe, maybe a little less than an inch). But there’s plenty of space between the front of the engine and the current radiator.

all of the wiring is brand new Ron Francis stuff. Went ahead and ran wires in the loom for the eventual addition of an electric fan setup. The alternator currently on the car isn’t the final one for when the fans are swapped, just one I had on hand that can keep up with my current accessories.

Removed the old York compressor and the Sears knee-knocker A/C unit for the eventual addition of a Sanden compressor and A/C retrofit.

Like I said previously, trying to cut down parasitic loss. There’s always some, but a fixed or clutch fan draws a lot more than electric, and on a smaller engine that’s especially noticeable.
 
You must log in or register to reply here.
-

Back
Top