Desert Cooler Radiator results

[Hammer H]

Hi All

I'm interested to hear from anyone that has fitted a Desert cooler radiator as to how much improvement can expected, in particular off road on 35-40c days.

addititionally has any body fitted a thermo fan replacing the viscous, and any pros and cons resulted in doing this.

Thanks in advance

Paul

[poleonpom]

Good questions, I'm also interested to hear the results.
Jonathan

[BusinessConnected]

I tried a Couple of Thermo Fans... Including the "High End" Craig Davies models and they just wouldn't cool sufficiently.

That was with a "New" Standard Radiator though... rather than the Desert Cooler.

I've just accepted that if its 35-40 Degrees and I'm stationary... The Engine will get warm :)

[Striker]

I've just accepted that if its 35-40 Degrees and I'm stationary... The Engine will get warm :)

I'm quite interested in cooling solutions, as I tow a 2.2 tonne food van.
Rain, hail, shine, or 45+ degrees, I need to get where I'm going without overheating.
My situation has improved considerably with some work (replacement radiator, service radiator, new thermostat, new temp sender), but I'm always after improvements.

--Striker.

[FANTOM P38]

Hi Guys I fitted a Dessert Cooler all Alum radiator some time back.
I also fitted new std thermostat & water pump/ serpentine belt at same time. Since day one it has kept temp marginally lower that normal std position - no matter outside temps!

When I ordered mine I had a bleed screw fitted to top tank which makes bleeding air out of the system a breeze.
The radiator is setup to allow fitment of std fan shroud & mount points so swapping over was also a breeze.
I did post up some pics on post about install at time so if you search you should find them.

So far all is good, I dont think about overheating any more :D

[mechanic2you]

Hi Guys


Can't see the problem with the original set up
We have a 1998 4.6 and when we did the engine we fitted the step sleeves and to this day no movement of the gauge including several Simpson trips in over 45 degrees
Regards
Peter

[Keithy P38]

I'm in two minds (sorry to detract from the original topic).

I agree with mechanic2you - I too have a completely standard cooling system on mine. It will idle through the scrub all day in low range 1st and the temp needle doesn't budge above half. This is in Tropical North Queensland summer heat.

I'd thought about it though, and the extra cooling capacity would be great - especially matched with a good thermo fan (imagine the fuel savings), but weighed up the cost plus the word "custom" makes things harder to get off the shelf in good time.

Each to their own - I'm neither for or against it. Just adding my 0.02 that the standard cooling system is more than up for the task.

Cheers
Keithy

[Hammer H]

Thank you Businessconnected ,Has anyone else experience with thermo fans, I can't imagine thermo fans can suck as much air as the viscous. On the other hand I believe thermo fans are fitted to worked performance hot rods, v8s, big blocks, or am I wrong?

[Keithy P38]

Mechanically driven fans are a thing of the past these days! Thermo fans must be a good thing!

Commodores haven't had belt driven fans since the 80's...

[TheTree]

Mechanically driven fans are a thing of the past these days! Thermo fans must be a good thing!

Commodores haven't had belt driven fans since the 80's...

A thermo fan should be fine as long as it moves at least 2000 CFM of air

Steve

[Hammer H]

Just had a short but interesting conversation with Desert Radiators, they said the standard radiator is good for street but no good for offroad, as is my experience. Said their radiator is twice the capacity of the standard radiator.

Asked about fitting a thermo fan and they said that fitting a thermo fan would be going backwards as the standard viscous is fine. I also can't see how a electric fan can pump as much air as A fan the size of the viscous hooked up to the motor, just my comprehension of it.

Also said would not be able to notice power gain by going to a thermo fan.

Any way based on my research I will go ahead fit one, test over January on sand tracks and post the results for those interested.

[Dougal]

Thank you Businessconnected ,Has anyone else experience with thermo fans, I can't imagine thermo fans can suck as much air as the viscous. On the other hand I believe thermo fans are fitted to worked performance hot rods, v8s, big blocks, or am I wrong?

Thermo-electric fans are not all created equal. There is a massive variation in power required and thus air moved. Even for fans that look pretty much the same.
They also need to be fully shrouded to suck air through the whole radiator. Unshrouded fans just recirculate hot air.

The one major advantage of electric fans is being able to move maximum air at low engine speeds. Viscous fans of course move most of the air at higher rpm.


A thermo fan should be fine as long as it moves at least 2000 CFM of air

Steve

Just be careful, many fans from non reputable brands claim fictitious airflow numbers. If anyone is serious then download a SPAL fan catalogue and have a dig through. They list power draw and air flow curves for all their fans. You can at least trust their figures.

You'll find Spal fans on most ferraris. Probably mafia connections.:angel:

[TheTree]

Just had a short but interesting conversation with Desert Radiators, they said the standard radiator is good for street but no good for offroad, as is my experience. Said their radiator is twice the capacity of the standard radiator.

Asked about fitting a thermo fan and they said that fitting a thermo fan would be going backwards as the standard viscous is fine. I also can't see how a electric fan can pump as much air as A fan the size of the viscous hooked up to the motor, just my comprehension of it.

Also said would not be able to notice power gain by going to a thermo fan.

Any way based on my research I will go ahead fit one, test over January on sand tracks and post the results for those interested.

I too had the same conversation with Norm and I disagree about the thermo fans, after all the later Rangies etc have them fitted

On thing is though that it is a lot more work to fit the thermo fan !

Since I have a good standard radiator and an engine watchdog fitted, I shall report on how it behaves offroad during the coming summer


Steve

[TheTree]

Thermo-electric fans are not all created equal. There is a massive variation in power required and thus air moved. Even for fans that look pretty much the same.
They also need to be fully shrouded to suck air through the whole radiator. Unshrouded fans just recirculate hot air.

The one major advantage of electric fans is being able to move maximum air at low engine speeds. Viscous fans of course move most of the air at higher rpm.



Just be careful, many fans from non reputable brands claim fictitious airflow numbers. If anyone is serious then download a SPAL fan catalogue and have a dig through. They list power draw and air flow curves for all their fans. You can at least trust their figures.

You'll find Spal fans on most ferraris. Probably mafia connections.:angel:

Yes agreed you must be careful and use a reputable manufacturer for the fan

Desert coolers came with a shroud and of course running one without a shroud is pretty useless

Norm told me the fan they supplied moved 2800 CFM of air so that seemed to be more than adequate

Steve

[Hammer H]

I see spal thermos can move up to 3000cfm, but I wonder how much air the standard viscous moves.

I also fitted a watch dog temp sensor and this is what has encouraged me to look at better cooling options.

As the watch dog climbed to 102 degrees Celsius the standard gauge said all was fine and had not moved at all. The day was pleasant October day maybe 25c it's the constant sand driving at low speed that woks the temp up, I also had the standard thermos on high with a bypass switch wich seem to help by about 2 degrees c.

I admit my my cooling system may not have everything replace recently, new radiator two years ago, but IMO the cooling system does not cut it for the 4wd I do, maybe it would if at 100 p/c.

[Dougal]

I see spal thermos can move up to 3000cfm, but I wonder how much air the standard viscous moves.

I also fitted a watch dog temp sensor and this is what has encouraged me to look at better cooling options.

As the watch dog climbed to 102 degrees Celsius the standard gauge said all was fine and had not moved at all. The day was pleasant October day maybe 25c it's the constant sand driving at low speed that woks the temp up, I also had the standard thermos on high with a bypass switch wich seem to help by about 2 degrees c.

I admit my my cooling system may not have everything replace recently, new radiator two years ago, but IMO the cooling system does not cut it for the 4wd I do, maybe it would if at 100 p/c.

102 degrees is completely normal. Why would the gauge move? They are built with a dead-band in the middle to not alarm easily worried drivers.

It's only above 115C that you need to start being careful.

[Hammer H]

Maybe I'm wrong, I thought getting to 105c was too hot.

[Dougal]

A 15psi radiator cap will stop water from boiling until around 120C. Glycol can push that higher (haven't checked).

[Hammer H]

Have now placed the order, hoping for the same results as Fantom P38, thanks all for your input.

im not replacing any other parts thermostat, water pump etc, so I will see the direct comparison and report back after some hot days in January.

Cheers

[TheTree]

Have now placed the order, hoping for the same results as Fantom P38, thanks all for your input.

im not replacing any other parts thermostat, water pump etc, so I will see the direct comparison and report back after some hot days in January.

Cheers

Good choice I reckon, let us know how it goes mate

Steve

[Hammer H]

Hi All

I'm very happy with how the Desert Cooler Radiator performed. Unfortunately there were no 40 degree days on my trip but I can compare against previous 30 degree days with the original radiator.

Where the original was reading 103c (watch dog temp gauge) and I was having to take it easy the Desert cooler was at 89c max only after switch off it would reach 95c as would be expected. (another member with a watch dog temp gauge reported they read 5c lower than the computer, so add 5c to watchdog to be safe)

I tried everything to get the temp up including full throttle soft sand driving, tyres at 15psi. Even leaving tyres at 40psi in sand, just could not get the temp up. Finally I can relax and feel comfortable about not overheating, and you don't get that concerning too hot smell and no more heat pouring out from under the bonnet.

It was a relativity straight forward fit, need to drill two holes in top of shroud for bolts. The only trouble i had was fitting the lower shroud which would have been much easier if i had of removed the fan.

Original radiator- Height 500mm Width 560mm Thick 41mm Holds 2.3 Litres
Desert Cooler- Height 500mm Width 530mm Thick 57mm Holds 4.5 Litres
Measurements across finns

Now I'm thinking maybe a large thermo fan may work in place of the viscous.

[Tombie]

So let me see if I have this correct...

You replaced an old factory radiator, flushed the block, maybe changed the thermostat etc and then topped up with fresh coolant and a new radiator and your engines running cooler?!

Sounds like the same benefit may have been gained by doing the same with a new factory cooler.

[Keithy P38]

Not sure Tombie - a two year old radiator wouldn't be far behind performance-wise to a new one unless it's coupled with poor coolant or a dirty cooling system, surely?

My rad is 4yrs old (but was brand spankers when I fitted it) and still looks extremely clean internally.

Cheers
Keithy

[BusinessConnected]

I've done the Full Flush/New Radiator/Thermostat etc on mine...
Nice to see the results of the Desert Cooler Radiator upgrade.

Next step in testing is to see their survivability when a Viscous Coupling Fan Blade Explodes :)

(That's happen to me once or twice... )

[Pedro_The_Swift]

Isnt that interesting,, an aftermarket rad manufacturer said the standard rad was not up to the task!!
Who'd a thought???:angel::wasntme:

several of us D2 boys just put a cooler thermostat in,, and the underbonnet temps of the D2 would scare you p38 boys legless!:p

I do like the idea of new bleed screws:cool:

[Keithy P38]

Does the temp get up enough to send the oxy sensors to closed loop Pedro?

[Tombie]

Not sure Tombie - a two year old radiator wouldn't be far behind performance-wise to a new one unless it's coupled with poor coolant or a dirty cooling system, surely?

My rad is 4yrs old (but was brand spankers when I fitted it) and still looks extremely clean internally.

Cheers
Keithy

Interesting, wonder if the dreaded blockages (casting material) still in the block are the cause and disturbed or compensated for by the larger cooler.

I know the 5.0L with Powerdyne blower attached never struggled with a factory radiator, 35's and a bit of fun...


Other potential heat retention issues could be old/blocked cats, and the desert coolers additional shedding capability may be compensating for the heat..

[Keithy P38]

I agree! There could be other potential factors at play!

When all is said and done, Paul has had a win with his new setup! I rekon he's one of a few who have results to back it up - temp watchdog being the big one.

Personally, I don't have a watchdog but have never experienced issues with the cooling system in hot bushy low range or sand driving in mine. And I do a lot of it.

I agree with Pedro's comments regarding underbonnet temps too, others have commented how warm it is under there when I lift the lid on mine.

Could this bring us back to the ventilation discussion from last year? I know these old girls like to run warm, perhaps not an issue in colder climates, maybe not so much over here?

Cheers
Keithy

[Hammer H]

I agree there Definately could be other factors, I replaced the thermostat, reused the drained coolant and topped up, didn't bother with flushing the Block, as time was an issue.

With the original radiator and previous radiator I would often experience that heat soaked engine bay leaving me thinking is everything ok. I purposely drove in a manner to increase the engine temp with the Desert Cooler but It wouldn't build temperature. The heat from the engine bay from my sense felt normal under all circumstances. (not p38 normal)

I've read that the p38 cooling system is fine if kept in tip top condition, thats ok but it leaves little room for error. And that's not too comforting considering the consequences of overheating these motors. Apparently the motors were originally built to run at around 75-80c but they have been tuned to run 90-95c to meet pollution requirements for the cats to be efficient. This last paragraph are bits and pieces I've read on the net so don't quote me on it but certainly the motor was retired after p38 so maybe it was maxed out.

I'm certainly happy with the result and would include the Desert Cooler ( larger radiator) in my top 5 mods for a p38, infact maybe second after 33 inch km2s.


Ps I'd like to acid test it in 40c plus though.

[benji]

Hammer thanks so much for that.
Numerous times I've had mine over 100 which doesn't sit comfortably with me, even though the temp guage was still on half - so obviously within factory limits.

Mine has a new cooling system on it, and in that situation I'd be on 96.

Sounds that's the go for me.


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[Pedro_The_Swift]

Does the temp get up enough to send the oxy sensors to closed loop Pedro?
I had mine replaced before the trip and the Mech said they were cooked well and proper. Hot enough to release electicians tape, hot enough to crumble plastic split conduit,,,,
The idea of extra airflow is tricky, hard to implement and even harder to prove. A second bonnett would be needed (have a long think about the engine bay of your p38 and get back to me, otherwise--),, you'd probably need one vent on each side, facing away or towards? away? what do you do with rain? How much extra noise will two holes in the insulation make?
Maybe under bonnet gopro's with ribbons to prove airflow?

so many questions

and dont forget,, the best rad in the world will still sit at the prescribed temp of the thermostat. So in a D2 it wont EVER get below 96.
thats why we changed thermostats.

[Keithy P38]

I was thinking of vents and proper ducting to get that heat out.

I'd like to know how it would go! I have a go-pro, lots of LED's and ribbon is simple. I can feel a science experiment coming on :-)

Cheers
Keithy

[Hammer H]

Been thinking about this, if air flow was the problem would mine not still suffer the the same problem with the larger radiator as the same amount heat still needs to be transferred through the engine bay?

Maybe the coolant passes through the standard radiator to fast to be sufficiently cooled in certain envirments and conditions pushing the engine temp higher

With the desert cooler there is almost twice the capacity which means coolant has almost twice the time to cool in the radiator, would that make it twice as effective?

I don't think too many of these vehicles would have seen of road use in their first several years and land rover know that (otherwise you woud be able to buy new range rovers today with 16in rims) and why increase production costs, also as someone mentioned before I don't think Aus and hotter climates are where they make the majority of sales.

It's just one of those things, I'm a bit biased now and converted as I also have had some melted pipes and had on many a previous occassional thought oh crap it seems hot under there.

[Keithy P38]

I like the sound of your radiator setup now, will be on my list when the time comes!

As for heat under-bonnet, I was more leaning towards getting it down to improve ancillary stuff rather than the actual engine temp!

[Pedro_The_Swift]

As for heat under-bonnet, I was more leaning towards getting it down to improve ancillary stuff rather than the actual engine temp!

yep!:cool:

[PhilipA]

Geez when you get old you remember a lot of stuff that you really wish you didn't.
I remember that LR changed the design of the top radiator hose something like at least 5 and maybe 20 times because the radiator is lower than the engine, and they persistently developed air locks in the top hose.

I have actually seen one blow off a heater hose offroad from the engine temp rise.

So I guess from that that the air lock problem is still around and maybe is the/a cause of the overheating in many 38As.

You apparently have to fill the things with the front up on a steep slope and even then any air left in pockets can still move to the top hose. Maybe fitting a bleed screw like the D2 diesel is an answer.

Regards Philip A

[Pedro_The_Swift]

Phillip, is that why the V8 d2's have the bleed screw at the 3 way hose junction?
engine height?

[loanrangie]

I always bled my rrc's either facing uphill or front wheels on ramps just to get the rad the highest point of the system.

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[Keithy P38]

I've never had a problem bleeding mine on level ground... Once the thermostat opens, vary the revs between 1500 and 3000rpm, a few stabs of the throttle from idle as well, and you'll soon blast those air pockets out. And removing the radiator overflow pipe until a steady stream of coolant comes out also helps...

[PhilipA]

Phillip, is that why the V8 d2's have the bleed screw at the 3 way hose junction?
engine height?
__________________

I don't know but probably.
That's the reason with a TD5.
However the 38A shape made the radiator lower so it should have had one also but maybe there was no room under the bonnet.
Regards Philip A

[benji]

The numerous changes in top hose shape happened in 95-96 if I remember the tsb's correctly. Initially the hose rose up high and then dropped to the radiator, but the later ones were more of a gradual rise.

I know when they first introduced the vouge se models they did a lot of hot weather testing in Australia. They towed a wind resistance trailer up around Alice Springs in the middle of summer, and consequently that's why those front spoilers have the rows of slits along their lower edge as it led to a 6 percent (memory is getting sketchy there) increase in airflow - but obviously not into the radiator due the that bottom plastic air damn.

On the classics you could fell a lot of heat coming out fromthe sidesof the bonnet. I've often wonders about taking off the front sealing rubber from the bonnet, but I can't seem to get the clips of without breaking them.

I've often wondered that due to the lse being their test mule in many ways that the new cooling system was somewhat of a theoretical exercise.

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[JohnnyB]

Has anyone got any long term results or issues with these Desert Coolers and and any suggestions