Cooling.... Clutch fan vs. Electric

[NDescent1]

I have a 73 Dodge Charger with a 318, currently a 2bbl but thinking of installing a 4bbl since i have all the parts laying around the garage. It constantly seems to overheat. i have a non clutch fan without a shroud. i've read that electric fan is the way to go but it is not a large motor or being dragged just a basic around town weekend car.. any ideas

Also having a hard time finding out the correct vacuum and sensor layout under the hood.. Not sure what is necessary ...

any help would be greatly appreciated...

 

[HT413]

I would do a search on this board for cooling issues. Electric fans are largely a waste, especially for a stock 318. Things I would look at are shroud, tstat, radiator (are the tubes plugged or oxidized), and flush coolant to see if there is any scale, also, check the timing - too retarded will cause heat.

 

[Bruzilla]

Your biggest problem is you have no shroud. Think of your cooling system as a water hose. Water comes in the front, travels through it, and exits out the back. Your cooling system works the same way. Air is brought in through the front, passes through the radiator to cool the coolant, then exits out the back cooling the engine directly. For an engine to remain cool, you need both the capillary cooling from the radiator and the direct cooling from fan blown air.

Now think of a sprinkler hose with lots of holes in it. Water comes in the front and sprays out everywhere.... great if you're watering the lawn but sucks if you need to fill a bucket. That's the problem you have right now. With the shroud the fan pulls air through the radiator, but without it the air is coming from both sides of the radiator, which is no good for cooling. And the shroud also directs the direct air from the fan to the engine. Without the shroud your fan is blowing air helter skelter throughout the engine bay, which doesn't help cool anything.

The problem with electrics is our cars weren't designed for them, so there is always going to be a trade off between capillary cooling and direct cooling, and there's no way to optimize them both. Depending on your make, model, and engine, some guys do have success, but many don't.

Your best bet is to get the right sized radiator, a shroud, and a clutch fan.

 

[Seax440Dodge]

agree with the above, I had a cooling problem once, car just had a flex fan on it... I put a fancy schmancy electric fan and aluminum radiator setup in it, and while it was better, it STILL got hot.. I ended up putting the stock radiator back in, with a clutch fan and shroud, and haven't had any issues since

 

[super-bee_ski]

X3!

Also, you live in Washington State, not a particularly HOT climate so, something "else" is going on there.

Bruzilla and Seax440dodge have both hit the proverbial "nail on the head" with their diagnostics.
Do these corrections first then proceed deeper if the issue continues.

Remember, many manufactures want your car to run 195 degrees.

 

[Dennis H]

Napa Superstat. Green. Shroud. Clutch.

 

[dangina]

if your gonna buy a clutch fan, get your name on the MP fan right now, I've been on the waiting list for almost 3 months now...

 

[73runner]

I had a 73 318 satty and it had no clutch but did have the stock spacer, flex fan and shroud. Never any issues..... Even after I upgraded the intake to a four barrel and put headers on it.....

Spacer and fan position to the shroud are critical for proper air flow (bruzilla is 100% on the mark). The fan should be an inch or so from the face of the radiator and stick out beyond the edge of the shroud for maximum efficiency.

I agree that you need to check the tstat and radiator.

 

[A383Wing]

shroud ain't gonna make much difference on a stock 318...I don't have a shroud on my 383 and it cools just fine. If it was made without a shroud from the factory, don't band-aid it, find out what's wrong first. I bet radiator is partially plugged. I'm running non-thermal clutch fans on my cars..

 

[Bruzilla]

It all depends on what car you have. That's why some guys have luck with electrics and some don't. Your 383 may stay cool in one of your cars. but looking at your page you don't own a 72. There's a reason why every 71-74 I've ever seen had a shroud... they needed one.

 

[NDescent1]

the motor is out of an 86 diplomat, roller rockers roller cam, 2bbl. i think i will look at clutch fan and radiator and tstat out the box. i believe i have a spacer somewhere from the engine swap 8 years ago. Thank you guys.. i appreciate it.. although i got it running again i never trusted it to drive farther then 1-2 hours from home now that i am able to take alittle time on it i want to make a dependable car. i do want to upgrade 2 4bbl but i read that i would want the 360 4bbl intake and not a 318 4bbl intake due to the chambers under carb clogging up..

 

[Feral]

I think Bruzilla is right, it's probably the shroud. I don't have a whole lot of experience with mopars, but I've had Chevy's in which cooling was a problem without a shroud.

Start with the basics, consider buying a shroud and checking your fan blades to make sure they've still got the right shape and angles to where they can move air like they're supposed to. If that doesn't work then check your thermostat, they're cheap so it wouldn't hurt to buy a new one anyway.

If that still doesn't work you should check your radiator and water pump, flush the radiator with a cleaning agent to make sure it's not stopped up and make sure your water pump is still doing it's job.

Also make sure you've got enough oil in the engine, that much should be obvious! ;)

As for clutch fan vs. electric. Honestly, unless you're building a nice street engine and trying to free up a few extra HP and revving capability, it would be best to stick with a clutch, or non-clutch fan. You're not really going to gain enough cooling performance to really justify the conversion.

One mistake I see people making is that they don't take into consideration that fans PUSH better than they PULL. They'll put them on the inside of the radiator and make the fan pull the air through rather than push, there are some circumstances on some cars where that might be the only option, but that too is something to consider.

 

[dangina]

when you get the chance read some reviews here:

http://board.moparts.org/ubbthreads...&Words=dangina&topic=&Search=true#Post8087849

somewhere in the post someone posted an article that compares stock fans of all sorts, very interesting read!