Electric fan won't cool at highway speeds

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11.2

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Just converted to an electric fan, cools great while bombing around town and sitting at lights with the ac on wich is where my clutch fan didnt keep up, thought I had the cat by the balls until I hit the highway. Fan is on 100% of the time and temps vary from 180-210 with no ac.
Seems like the fan is actually blocking the air at hi speeds, any suggestions ?
 
Pusher or puller fan?
Shroud or no shroud?
Fan CFM?

Sorry, IMO, the factory viscous fan with a shroud is basically an unbeatable set up unless you really are going balls to the wall.
 
It's a puller with a shroud. I read some old posts and sounds like a common problem due to air going around the rad instead of through it. I'm on holidays right now, cars will see about 3000kms of highway driving, I think I'll just try to get a 160 thermostat for now, I know it's a band aid but just wanna cruise instead of wrench
 
11.2 said:
Just converted to an electric fan, cools great while bombing around town and sitting at lights with the ac on wich is where my clutch fan didnt keep up, thought I had the cat by the balls until I hit the highway. Fan is on 100% of the time and temps vary from 180-210 with no ac.
Seems like the fan is actually blocking the air at hi speeds, any suggestions ?
Click to expand...

So what's the issue, other than the fan runs constantly?

A 160* stat is a step in the wrong direction IMO.
 
The fan isn't supposed to do squat at hiway speed anyway.
Probably more of an airflow volume issue.
 
Bad Sport said:
So what's the issue, other than the fan runs constantly?

A 160* stat is a step in the wrong direction IMO.
Click to expand...

x2 and 180 to 210 is not running hot but you do have air blockage going on the fan should be off and the temp down most of the time at highway speeds .
 
No fan helps after 50 mph. Stay with 190-180 thermostat. Your not hot till you get onto the 220-230 range. Make sure you use antifreeze and at lease a 10+12 lb cap on the radiator.
 
tekslk said:
No fan helps after 50 mph. Stay with 190-180 thermostat. Your not hot till you get onto the 220-230 range. Make sure you use antifreeze and at lease a 10+12 lb cap on the radiator.
Click to expand...

^^What he said! Use a thermal fan switch so it should coast at cruise and not be blocking more air than it pulls. You can also examine areas around the radiator and bumper where you may be able to improve air flow airflow through the radiator. Air dams and shields are common on later model cars to help funnel the air at speed. Blocking areas that may allow air to bypass etc.... Some have a seal between the core support and hood for this reason.
 
My Spal has thin rubber flapper panels that open up at higher speeds allowing more air through.
It seems to work pretty well keeping a 360/380 magnum comfortable at highway speeds and
might be an easy DIY fix.
 
Installed a 160 thermostat, cleaned ac rad and tranny cooler, rigged some carboard for temporary wind guides and very little improvement. It will get me through the trip but the clutch fan is going back on when I return
 
Someone else already asked this, but I will again,

What is wrong with 180°-210°?

There is nothing to worry about. And a 160° thermostat will not make it run cooler. That will just make it warm up slower. Once you hit 160° it's open and still open at 180°, just like a 180° thermostat is open at 180°.
 
69_340_GTS said:
Someone else already asked this, but I will again,

What is wrong with 180°-210°?

There is nothing to worry about. And a 160° thermostat will not make it run cooler. That will just make it warm up slower. Once you hit 160° it's open and still open at 180°, just like a 180° thermostat is open at 180°.
Click to expand...

you can lead a horse to water but you can't make him drink.
 
69_340_GTS said:
Someone else already asked this, but I will again,

What is wrong with 180°-210°?

There is nothing to worry about. And a 160° thermostat will not make it run cooler. That will just make it warm up slower. Once you hit 160° it's open and still open at 180°, just like a 180° thermostat is open at 180°.
Click to expand...

AIRFLOW PROBLEM, like stated above !
 
With the clutch fan and 180 stat the temp stays at 180 and doesn't budge , I don't like watching the gauge fluctuate by 30 degrees. i just need to fab a better shroud for my clutch fan so I can run my ac at the lights. That's the only reason I tried the electric
 
is it running lean or the timing off at highway speeds??? electric fan is probably hurting air flow at highway speeds too. shouldn't even need a fan at highway speeds. its not doing anything hen.. its really there for idling and low speed where you don't naturally get that air flow through the core.
 
pauly v.100 said:
My Spal has thin rubber flapper panels that open up at higher speeds allowing more air through.
Click to expand...

This is exactly what you need to replicate. The shroud is blocking the free flow of air at higher speeds. Like said before, you are not really overheating but I dont blame you for not liking the temp spikes. Even though its not dangerous for the motor you realized something is not right, and this will be an easy fix to get the temps to settle down.
 
I'll check out those flaps, maybe I can fan something up. It's amazing what we done with carboard yesterday. Lol.
 
11.2 said:
I'll check out those flaps, maybe I can fan something up. It's amazing what we done with carboard yesterday. Lol.
Click to expand...

I'd be concerned about running the 160* stat. If it doesn't come up to a decent operating temp, you are damaging the internals (think sludge and excessive wear on parts). That's why I said it's a step in the wrong direction, IMO.
 
hmmm....I almost never turn my fans on., in my 74' 360 Dart Sport....with cheapy 26" Ebay Radiator.

How about this?

........ cruising, loaded out, 1000lbs of crap in the trunk, 2 adults, a 4 year old, and a 12 yo Cat....couldnt fit a Shoebox in the car anywhere we were so loaded......

Drove from Texas to Oregon....85-105* outside.....over 2000 miles......and never even turned the fans -ON-.

On one leg of the journey in Utah...on I-15 between Salt Lake City and Boise, Idaho......we were cruising at 100mph and getting left behind.....but my 360's temp never broke 185*.

How about some more information....Does your System build/hold pressure/or leak?
What pressure radiator cap are you using?
What are you trying to cool down?.....a 67 Valiant you converted from /6 to 440?
18" radiator hole.......7.2L of big block behind it?
:violent2:

Although it is a good design and works
Im never running a mechanical fan on my car, ever again.
 
I bet there is an undersized or clogged radiator behind all this.

The rule of thumb is that overheating at idle is nearly always airflow related, while overheating at highway speed is a capacity problem. You seem to have some of both.

What radiator is in there?

Even with stock smallblocks I've found that a 26" radiator and deep-pitch thermostatic clutch fan was the only combo that would reliably stay cool.

With the AC condenser and trans cooler both in front of the radiator it's probably simply being overtaxed. The solution may be to upgrade the radiator and install a small pusher fan in front. That's not uncommon even with an engine-driven fan if the engine bay is too tight to move hot air out.

Everybody and I mean EVERYBODY plays the 160 degree thermostat card first because it's much cheaper than a radiator but that's just wasted money and effort. The thermostat is open at anything above it's rated temperature and if the temp keeps going up past that you have problems ELSEWHERE.
 
TylerW said:
I bet there is an undersized or clogged radiator behind all this.

The thermostat is open at anything above it's rated temperature and if the temp keeps going up past that you have problems ELSEWHERE.
Click to expand...

I would add that it is possible the cooling passages in the block are full up to the freeze plugs with Scale...and coolant flow is taxed as well....

What he said....^^^
 
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