2 core versus 3 core radiators

[sooty_10]

Just throwing my experience out there, My TD42t used to get warm (3/4) when I lived in the NT on long drives in hot humid weather eg. on a Katherine to Broome trip. I'd just keep an eye on it and maybe toggle the aircon just to confirm I could drop it if needed, as soon as the aircon went off temps would drop back under half.

Now when I did my engine conversion the original radiator was damage (from my accident) and I ended up buying a cheap Chinese alloy 3 core radiator. Installation needed a little modification of the top radiator mounting tabs, I just slotted them out so the radiator could be pulled closer to the support. Other than that I haven't had a single problem. It's been in for over 2.5 years now and done heaps of trips, including one to Beachport/Robe, and temps never really rose much.

The other week I was in Bright and did a track which was pretty constant and steep with switchbacks etc in 40 degrees, and low and behold temps rose. This time I had an Auber digital temp guage and warning alarm set at 110. On the factory gauge it got to 3/4, and temp reading was up to 115 max, however when it initially spiked high it was after a decent long climb and we stopped and I turned off the engine (no thought involved there). As soon as I got back in without the engine running the temp spike and alarm was going off, obviously due to no engine fan running or airflow and heat soak. As soon as I started the engine back up temps dropped pretty quick to around the 105 mark (we were still doing a massive climb). It wasn't until we got to the flatter ridge line that temps dropped below 100 and then stayed in the 90's.

That was with the original engine fan, fan clutch and thermostat from when I bought it over 5 years ago with the cheap Chinese alloy radiator.

The cooling system is definitely on my to do list for an overhaul, but I'm happy with how it is running under what I would call a fairly extreme condition.

And saying all that I haven't had the radiator out since I installed it, so no doubt there is some wombat mixed with local muds in there somewhere. Next service I might do a coolant change and pull the radiator out for an inspection.

[liftlid]

This is for both, what gauge are you going by the factory gauge or and aftermarket one ?? If the its in good condition have you had the radiator tanks removed and the core cleaned out internally to see if the tubes are blocked??

Going by the factory gauge as I don't need to know the exact water temp just how much it's changed from "normal" . I know from experience that with a clean radiator it will run about 1/4 on highway and around town, with a dirty rad (mud) it will be at 1/2 , then on a hot day and more load than normal (hills,loaded rack etc) it will max at the 3/4 if the clutch fan is working. As soon as you back off the power the temp drops.
The rad was flushed in June 2014 (I get it done every 12 months)

[Bigcol]

This is for both, what gauge are you going by the factory gauge or and aftermarket one ?? If the its in good condition have you had the radiator tanks removed and the core cleaned out internally to see if the tubes are blocked??

factory dash gauge - sits on just below half (about 85* off a 90* angle)
Autron Temp gauge - sits on 95* - to 110* (alarm goes off at 115*)
engine bay Temp (Autron) was sitting on 72*
EGTs 300* - Autron
Boost 8lb -Autron
sitting on 95kms

slight hill / gradual rise -
temp alarm goes off
factory gauge goes just past half way ( to about 92* off a 90* angle)
air con goes off
boost spikes to 12lb
EGT goes to 550*

radiator was replaced with new Nissan rad Xmas 2011
rad was flushed Xmas 2013
using factory coolant

is it my rad........????
is it my thermostat..........?????
is it my water pump.........?????
is it my Viscus fan...........?????
is it the fan itself.............????
is it a shit heap because the air con goes off when its a 43* day...........YES..............

I welcome your suggestions...........

[Dales300exc]

factory dash gauge - sits on just below half (about 85* off a 90* angle)
Autron Temp gauge - sits on 95* - to 110* (alarm goes off at 115*)
engine bay Temp (Autron) was sitting on 72*
EGTs 300* - Autron
Boost 8lb -Autron
sitting on 95kms

slight hill / gradual rise -
temp alarm goes off
factory gauge goes just past half way ( to about 92* off a 90* angle)
air con goes off
boost spikes to 12lb
EGT goes to 550*

radiator was replaced with new Nissan rad Xmas 2011
rad was flushed Xmas 2013
using factory coolant

is it my rad........????
is it my thermostat..........?????
is it my water pump.........?????
is it my Viscus fan...........?????
is it the fan itself.............????
is it a shit heap because the air con goes off when its a 43* day...........YES..............

I welcome your suggestions...........

Well. After my conversion mine was getting up to 110° rather consistently without much trouble at all down the highway. Small trailer in tow. Mid 20° ambients.

I was running a less than 12 month old 3 core brass copper rad.

Almost every part was new from the conversion except for fan hub. Radiator was cleaned.

To start with, from memory i fitted a high flow water pump with no gaskets from patrolapart to minimise housing clearance. I seemed to now be running closer to the 100° water temp mark.

Still wasn't too chuffed after some big range pulls seeing it creep to the 110° mark still.

I changed the fan hub with a new genuine fan hub and the fan blades to straight ones that are meant to flow better. Was now in the 90° range.

Finally i changed the thermostat to a tridon high flow to get the bypass valve closer to the port (its still not great clearance but was easier than modifying a dayco thermostat). At this time i also fitted a PWR 2 core alloy rad.

Now i consistently run between 78° and 82°. Keeping in mind I run a 77° thermostat.

BACK TO THE ORIGINAL QUESTION THOUGH.....
I much prefer alloy even if they can not be repaired half the time, they dissapate heat much better and temps recover a lot quicker after big loads.

There is a reason no new cars run brass copper rads anymore, because it is old technology that is no where near as efficient as modern alloys.

[Dales300exc]

Also, if you can stretch the budget a little, genuine replacement alloy with plastic tank rads that came in late model gqs can be bought new from patrolapart. They said they would have stock after chrissy and they were somewhere between 400 and 500 dollars.

They seem to get a good wrap

[the evil twin]

snip

slight hill / gradual rise -
temp alarm goes off
factory gauge goes just past half way ( to about 92* off a 90* angle)
air con goes off
boost spikes to 12lb
EGT goes to 550*


is it my rad........????
is it my thermostat..........?????
is it my water pump.........?????
is it my Viscus fan...........?????
is it the fan itself.............????
is it a shit heap because the air con goes off when its a 43* day...........YES..............

I welcome your suggestions...........

Hiya Col,

Please excuse the snip and my Boldface.

You are running D Gas and EGT's of 550, if you lift the welly a tad the overheating problem will go away.
It is the engine load driving the coolant temps not a faulty component as such.
If it was cooling system unserviceabilities the EGT would stay much lower and only Coolant temp rise astronomically.

If you want to keep the welly buried then you will need to improve the efficiency of the cooling system and go for a different radiator.

Nothing you have is broken as such, just not efficient enough to handle the heat load

[Bigcol]

Hiya Col,

Please excuse the snip and my Boldface.

You are running D Gas and EGT's of 550, if you lift the welly a tad the overheating problem will go away.
It is the engine load driving the coolant temps not a faulty component as such.
If it was cooling system unserviceabilities the EGT would stay much lower and only Coolant temp rise astronomically.

If you want to keep the welly buried then you will need to improve the efficiency of the cooling system and go for a different radiator.

Nothing you have is broken as such, just not efficient enough to handle the heat load

my thoughts were.........
thermostat maybe on its way.....1%
water pump not 100% efficient - 5%
viscus fan on its way - 5%
cracks in fan (not sure, havent looked) - 2%

spend a small fortune, and maybe - just maybe gain a better cooling rate.........

[the evil twin]

I am interested in the difference in 2 and 3 core radiators and have been told that 3 core are really only any good for towing and that with a lot of 4wding they clog up to easily.

I am looking at a copper/brass job but am unsure which way to go.. I would like any input from people who have actually fitted one.

I have to sell an injector pump to pay for it (so want to make sure I get this right) and will be selling a near new alloy radiator ($80) that is shit...lol.

I haven't replied earlier because I have only run Nissan factory rads and you were after comment from people running aftermarket.
Every "independant" rad specialist I spoke to over the years rates factory better than standard after market as a like for like swap

AFAIK the core debate works like this.
In copper a 2 core in alloy a 3 core.
Copper is a much better heat dissapator than Alloy BUT Alloy technology allows a larger amount of fin area.
Bottom line is if you have two equally efficient radiators of differing material the alloy will need to have more cores to get more fins to catch up on the heat transfer efficiency of copper as a material.

Alloy is becoming the modern material of choice because it is waaay cheaper than copper and heaps lighter so it is a $ decision by the manuf.
Alloy is nothing like as robust and is harder to repair.

Obviously the above applies when comparing like for like.
If you head off into the world of specialist high efficiency niche manuf then you have to trust their reps and their figures.

Sooo if it is copper versus copper as you mention then the more cores, the more efficiency, the more fins, the more air passages but smaller so, yes, they do block easier.
With what and to what degree depends on the individual

Hope that helps altho it may only start another 5 pages of shitfight

[the evil twin]

The zd has more electronics to run more efficiently alot like carby vs efi so it will be significantly affected by water temp coz of the coolant temp sensor adding and decreasing fuel with different temperatures

Uummmm... sorry but I have to disagree.

Coolant temp is only used by the ECU for fuel mapping when you start the engine as a function of temperature against RPM.
2. Fuel Injection Quantity Control
(i) Fuel injection quantity at engine starting
At engine starting, the fuel injection quantity is
determined by the engine speed at starting and cooling
water temperature

Once the engine is running the Coolant temp has little effect on ECU mapping

Also now is probably a bad time in this discussion but the ZD30 Thermostat is in the Coolant Inlet housing and not in the traditional position of the Coolant Outlet prior to the coolant leaving the engine for the radiator via the top hose.

[Alitis007]

Uummmm... sorry but I have to disagree.

Coolant temp is only used by the ECU for fuel mapping when you start the engine as a function of temperature against RPM.
2. Fuel Injection Quantity Control
(i) Fuel injection quantity at engine starting
At engine starting, the fuel injection quantity is
determined by the engine speed at starting and cooling
water temperature

Once the engine is running the Coolant temp has little effect on ECU mapping

.

Maybe coz its not as clear cut as carby v efi but coolant temp plays a role during running aswell.

Because I'm only guessing I have copied some text from the manual which should set some things straight, or add to the confusion and blow out this slight hijack even more.....

ENGINE COOLANT TEMPERATURE COMPENSATION (When starting)

For better startability under cold engine conditions, the fuel injection
timing is compensated according to the engine coolant temperature.

ENGINE COOLANT TEMPERATURE COMPENSATION (During driving)
For better exhaust efficiency under cool engine conditions, the fuel
injection timing is controlled within a compensation range depending
on the engine speed, engine coolant temperature and amount
of fuel injected.






this is for big col
Air Conditioning Cut Control
This system improves acceleration when the air conditioner is used.
When the accelerator pedal is fully depressed, the air conditioner is turned off for a few seconds.
When engine coolant temperature becomes excessively high, the air conditioner is turned off. This continues
until the coolant temperature returns to normal