Mopar Forums

Mopar Forums (/forums/)
-   Engines, Exhaust and Fuel systems (https://moparforums.com/forums/f81/)
-   -   Cooling requirements (https://moparforums.com/forums/f81/cooling-requirements-17113/)

Leem Apr 13, 2014 05:21 PM

Cooling requirements
 
Can somebody tell me what the rough CFM for an electric fan I would need for cooling on a 318?


Thanks,
Marty

440roadrunner Apr 13, 2014 10:39 PM

This might be the wrong approach for many reasons

1......"Home design" of electric fans seems to be pretty elsusive

2.....Many aftermarket fans seem to be over rated at best and outright lies at worst

3......Some guys have had good luck pirating commercial setups out of late model cars

4......Anything you design, regardless of so called CFM ratings depends on the "coil" (radiator / heat exchanger) you put it against AND the conditions under which this is done, IE if the blades are too close to the coil, the thing won't flow as rated, and if the shroud is improperly fitted, THAT will impact flow ratings.

I'm no expert at this stuff and I spend more than 12 years doing service work on stuff like refrigeration and heat pumps. Airflow and CFM can bit you in the ass when affected by "other stuff"

To sum this up, and all the above is simply off the top of my head, "it's a loaded boat."

Best advice I have is tramp around the forums and magazines until you pin down a specific combo that looks like you could duplicate

AND IF THAT isn't bad enough, HERE is what I believe happened to me

Over on "another group" is a guy called "Oldmanmopar" who's had enough of these cars I can't count. He claims he thinks that under some conditions some radiators can reach a condition whereby the fins crack loose from the tubes due? to? thermal cycling, tube expansion, whatever?

And I believe this happened to ME

I have two nearly identical radiators, one tested by a rad shop, and the guy claims it "flows fine." It does not cool worth a hoot. The second one is used, I did not clean it out, just "threw it on" one afternoon, and the change was DRAMATIC.

So, mull that'n over..............

Archer Apr 14, 2014 05:44 AM

Marty -

Is the engine fairly stock or "worked" and if so how much HP do you think it's putting out? What car it's in is a factor too.

That being said, with an electric fan it's kinda hard to go too big, since they are usually thermostatically controlled and only work when needed.

Archer

Leem Apr 14, 2014 03:16 PM

The 318 is fairly stock, out of an old Challenger. It is going to be put into my recent acquisition, a 55 Powerwagon. I have a dual electric fan setup in my Duster, a 383 and it seems to work well for me. Can't remember exactly what its cfm rating is, but I think it was in the 2000's. While the 318 is not some monster machine, it will have a lot of weight to move around. So I kind of am thinking the higher the better.


Marty

Skwerly Apr 14, 2014 05:10 PM

Back in the day, i chucked in a good-sized sixty dollar fan on my '68 Fury/318 setup and it never, ever overheated.

Coronet 500 Apr 14, 2014 05:21 PM

If you look up the fan manufacturers recommendations it's 2500cfm for a small V8 and more for bigger engines.

My opinion has always been must have a shroud as long and streamlined as possible.
Belt driven is my first choice always unless not physically possible.
Electric fans and pumps are for race cars.

If you do go with an electric put blow through baffles in the shroud.

Leem Apr 14, 2014 05:54 PM

Lol...well I won't be racing this thing. But I think I need the room.


Marty

Skwerly Apr 15, 2014 10:04 AM

The electric fan on my Fury freed up a LOT of low-end grunt. Best mod I ever did, if you ask me. just make sure your alt can handle the load down low. :D


All times are GMT -7. The time now is 01:06 AM.


© 2026 MH Sub I, LLC dba Internet Brands