Cooling issues

Your issue is the fan(s). I highly suggest a Volvo fan and relay setup. Google will provide you with everything you need for the easy conversion.
Real life application inbound.
My Ranger up until this winter had the following engine and cooling mods:
400+ HP 306, 10.7:1 CR, stock type water pump, 195 t stat. Doesn't run hot even on prolonged beat downs. It may stay warm (220-225), but doesn't overheat. What magical radiator was I running? Stock 1999 3.0 V6 rad. But with a nearly fully shrouded Volvo fan and 2 speed controller. They flat out work and are easy to package.
 
Ok; so I relied on mechanics I know & personal experience. Which "seem" to be wrong. But, as said there are variables. I've worked through problems with my CJ, different radiators, fans & thermostats. Each change seemed to make some difference, weather better or worse. I saw the biggest cooling difference, after adding the Flowkooler pump. The article by Flowkooler seemed toposibly argue with even needing Their pump. Bill Vista > well, I don't have a PHD, so all I got from that was Cooper cools better, But, it's right back to "Application & design. Overclockers, damn, I don't have all night to study that one. Cool, Be-Cool, enough, right?:)
 
Ron said:
No this isnt accurate. Physics works the same for everyone.

Now there can be variables that someone doesnt understand at play that they miss.

A key example of that would be someone buys a brand new thermostat that is bad or they damage during installation. Vehicle still overheats. They go back and buy a new T stat with a higher rating. This one isnt bad or damaged and it works.
Then that person draws the wrong conclusion that a higher tstat is better and spreads the story.

On top of what @Bebop linked I could write a book on cooling that most dont understand. People want easy platitudes not thorough understanding.

Just like your 2 row versus 3 or 4 row example.
Its isnt universal. There are many variables here such s the size of the cores, the arrangement of the passes and the material. I could easily design a 2 row that cools better than a 4 row I design, or a 4 row that cools better than a 2 row just by changing those variables. Again people see the simple 2 vs 4 and they understand that so they spout it off. Then companies see that and take advantage of it by marketing cheaper solutions just to increase sales.

If you really want to dive into this Ill be glad to post a wall of text tonight that explains it.
But in very very short. If you keep water int eh radiator "longer" in theory, that also means the rest of the system is in the block longer. So even if you could cool the water in the radiator more, you would also heat the water in the block more and would therefor cause the entering water into the radiator to be a higher initial temp than if you just cycled it faster.
The faact that temp delta and rate of change is exponential actually makes that last argument moot because it isnt even at play, I'm just saying if you COULD correct for that it STILL wouldnt work.

I'm sure @CasterTroy has some awesome experience with industrial cooling such as CRAC and cold row/hot row and how this all fits in,
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I've thought for a long time that the "water speed" myth probably has a lot to do with pump cavitation if the pump is mismatched for the wrong pressure or RPM, of if the pump design just sucks. That kills pump efficiency, and could very likely get blamed on some assumption about coolant velocity instead of what's actually happening. I seriously doubt anyone but pump manufacturers or radiator manufacturers are doing flow velocity measurements or mass flow measurements to see what the actual velocity is, and all of that goes out the window if you're using some un-validated radiator/pump/engine combination.

The laws of thermodynamics work just fine, and it can all be explained if you actually know what the conditions are.


Edit: I just read the article by the motorcycle guy. He's saying the same stuff that I am, but he's a lot better at it. :D
 
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bigassedredjeep said:
I don't think it was mentioned, is that the factory CJ radiator?
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yes, HD stock CJ radiator. I"m looking to get the timing checked in next few days. I double checked the pump I put on, and it said a counter clockwise direction- I started the jeep and verified the pump runs in counterclock wise direction. ( with me looking at pump from front of Jeep).
The motor has a history of running on the warm side. With the old set up, it would get warm, I'd turn on fan and it would cool down, I'd shut fan off, and it would repeat. with fan in "auto"mode, it wouldn't turn on- so I'd manually turn it on. - seemed to chase my tail.
I thought I may have had a bad controller, so it was a changed out with new one when I put the dual fans on there.
 
My problems were mostly on 4 wh low, crawling a trail, at near idle. I've never found an answer to, "is it water flow, or air flow"?
But the FlowKooler seemed to fix it, so that seems to be waterflow.
 
Ron said:
To be clear I am agreeing with you.

The caveat is, in SOME cooling applications (Im thinking industrial and equipment not any auto Ive ever encounterd) the thermostat can be a full stop where flow is prevented, (in which case the water isnt indded moving as stated above) and there is a bypass where jacket water is re-circed until reaching "operating" temp and then and only then will any (new) fluid enter the radiator.
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Sent you a PM the other day; didn't know if you got the Alert?
 
Ron said:
The caveat is, in SOME cooling applications (Im thinking industrial and equipment not any auto Ive ever encounterd) the thermostat can be a full stop where flow is prevented, (in which case the water isnt indded moving as stated above) and there is a bypass where jacket water is re-circed until reaching "operating" temp and then and only then will any (new) fluid enter the radiator.
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That's how automotive engines work. Unless it's a race engine that doesn't have a thermostat and doesn't need a bypass because of that.

I'm confused. :confused:
 
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Fabrik8 said:
That's how automotive engines work. Unless it's a race engine that doesn't have a thermostat and doesn't need a bypass because of that.

I'm confused. :confused:
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Yep, thats what I get for multitasking.
You are correct and my post was confusing.

In my mind I was thinking about variable flow design systems where an electric water pump shuts off and flow is completely halted until warm up...and then I pivoted mid type thought stream and ...yeah you get that with dumbasses like me.
 
jody - which Volvo fan do you have installed ? It sound like just what i need.....
A quick search provided more questions......

Amazon --,

Dual Radiator and Condenser Fan Assembly - Cooling Direct Fit/For 306686296 07-15 Volvo S80 3.0/3.2/4.4L, 15-16 V60 3.0L, 08-10 V70, 10-15 XC60 3.0/3.2L, 08-16 XC70 3.2L​

[]​

Radiator01.jpg
1) Dimension of it?
1)How thick is it at widest point ?
.
Im sure ill start a new thread......
Thanks :)
 
You need a used OEM fan, the replacements from china are junk.

Volvo 740/940/S70.

Make sure to grab the relay that comes with it.
 
It's about 17" in diameter.

Looks like this (with the relay you want to keep).

volvo_940_fan.JPG


You can unbolt it from its shroud and bolt it to any flat shroud of your choosing.

P1100053.jpg
 
rodney eppes said:
A few years back, the fad was a Taurus fan. Volvo must have blown past them! ;)
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The taurus fan and the volvo fan are the same thing. But the volvo one has a detachable motor fixture which makes it more desirable and easier to fasten to a fabricated shroud like I showed up there.

yager said:
What caught my eye was that it looks like a brush-less motor.
Thanks guys!!!
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It is not. Double wound motor which enables the 2 speeds.

If you want to go with a brushless option, there is plenty more tech to add, but I figure we'd keep it simple for this CJ.
 
Finally an update on this.
Timing- was off! We found it to be 22 degrees and put it where it's supposed to be- 12 degrees!
I better sealed off the area above the electronic fan. Only have a very minimal 3/8 in gap there now..
I feel the fans are working as they should.
At idle it will come on / then off at 60% to keep the temp down...
However, I'll take jeep for 10 mile ride and temps will still climb north of 220.
I'll pull over and the electric fans will be at 100%.

I've put the fans at 100% and taken for ride. they still will creep up and go North of 220.
I've taken some temps. at the upper hose temps are 220 which makes sense, but at lower outlet, I'm looking at 170's.

I'm thinking it's the radiator....

what say you guys??

I appreciate your thoughts/ feedback!

Brian
 
170 at the lower radiator hose is pretty awful. Should be pretty cool by that point. My guess is new rad.
 
Ooooor, you need better fans and to clean the rad.
If it doesn't leak I wouldn't change it yet.

I will reiterate that your shroud system is less than ideal. 3/8 gap is a massve air gap. You should have 0.00" gap. See pics or properly constructed shroud I posted earlier in thread.
 
Bebop said:
I will reiterate that your shroud system is less than ideal. 3/8 gap is a massve air gap. You should have 0.00" gap. See pics or properly constructed shroud I posted earlier in thread.
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I cant say definitively (no one can with info provided) that it is your only problem, or that eliminating it will solve your problem.
But think of this in terms of water flow vs airflow...and air will go through smaller cracks than water. If you are sized "marginally" and you need every last drop of air to cool...and you have a 3/8" gap, just imagine home much air efficiency is being lost.
Its like pouring water through a perforated pipe into a bucket.
 
NickMaul said:
170 at the lower radiator hose is pretty awful. Should be pretty cool by that point. My guess is new rad.
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I had my infrared thermometer with me the other day. Left work on a 90* afternoon, & drove my CJ about 8 miles to a restaurant. Electric gauge showing about 185 -190. Cut engine off, got out, shot the bottom tank, & got 170. Shot top tank at 195*. My radiator has been cleaned & rodded. Two row stock CJ.
 
I'm going to fix the gaps in current shroud. See if that works...Plan B will be a Taurus or Volvo fan. I've been doing some reading on them and they look like it would be an appropriate choice...If I strike out there...I'll consider radiator..
@rodney- what engine do you have in your CJ?
 
viper red cj-7 said:
I'm going to fix the gaps in current shroud. See if that works...Plan B will be a Taurus or Volvo fan. I've been doing some reading on them and they look like it would be an appropriate choice...If I strike out there...I'll consider radiator..
@rodney- what engine do you have in your CJ?
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I pulled the original 304 & installed a remaned 360. 2bbl, mild cam, 30* over, on the bore. Flowcooler waterpump, shroud, 16" fixed steel dirt track fan.
 
77GreenMachine said:
I wonder if going down the road the air is fighting the fan, as in the fan is moving less air then what’s being forced in at speed. The fan shroud I’m waiting on fedex to find (lost in the hub again) has rubber flaps that will open at speed.

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you dont need that on a jeep. At 100+ sustained maybe, and then it would be more about more speed than more cooling.
What that really needs is a funnel not gimmick flaps.
 
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