Defender 300TDI Radiator Tropical Mod

[isuzu110]

Hi All

I mentioned this briefly on another recent post, but prior to Christmas I had my 300TDi Defender radiator modified to reduce the size of the bypass hole. Our South African friends call this the "Tropical Mod"

I know the diagram below is not strictly of a 300TDI Defender, but in the LH tank (non-oil-cooler end), there is a hole about the size of a 10c piece in the horizontal baffle plate between the upper and lower portions of the tank. You can see this hole if you unscrew the radiator filler bung and drain the radiator to below the level of the baffle (approx half-way).

https://www.aulro.com/afvb/images/imported/2014/01/1370.jpg

I had the end tank sweated off and the hole reduced to 2-3mm, still allowing the tank to bleed air through the smaller hole.

Some South African forumites report seeing radiator temperatures reduce by as much as 10 degrees C, and this was consistent with my experience over Christmas. Whilst towing my camper trailer up Cunningham's Gap west of Brisbane, pushing EGTs of over 600 degrees (with ambient temps over 30) , my factory temp gauge stayed around half way and my EMS2 temp gauge show temps no greater than 95 deg as measured at the top of the thermostat housing. Previously I had seen 105 degrees and the temp needle go into the red.

When I pointed out the size of the original bypass hole to the manager of the radiator shop, he just said "what were those Poms thinking ?"

The complicating factor for me was that I replaced the viscous fan at the same time (not sure if it was cactus, but changed whilst I was tinkering) so I'm not sure how much that was a contributing factor to cooler temps.

Very happy. Mod cost ~$180 (fit/refit done by me), but I suspect I paid a premium as it was a rush job for the radiator mob in the final days before Christmas.

[weeds]

interesting as was thinking of getting my raditor overhaled prior to our trip this year

[steveG]

Was the hole the only thing that the radiator mob did, or did they give it a quick clean out/rodding while they had the tank off?

Steve

[Bush65]

It is a few years or more since I played with a 300Tdi, but unless my memory has deserted me, the baffle in question is in the LH tank, not the RH tank with the oil cooler.

[isuzu110]

John - thanks for the pickup. Yes, it was the tank on the passenger side of the vehicle. I've edited the post above to reflect that.

Steve - Whilst it was there, I did get it rodded again (this place wanted to remove other end tank as well to do that). I don't believe blocking/rodding was the issue though as it was rodded 18 months ago and there was no real temp change after the previous rodding.

[Blknight.aus]

the hole is there to stop you from cooking the engine in sub zero temperatures.

with the airflow coming through the radiator if its cold enough the coolant freezes in the cores and stops the coolant flow through the radiator,

[wrinklearthur]

the hole is there to stop you from cooking the engine in sub zero temperatures.
with the airflow coming through the radiator if its cold enough the coolant freezes in the cores and stops the coolant flow through the radiator,

I hadn't thought of that, but you are right it would be a safeguard against freezing in sub zero temperatures.
Not a likely thing to happen here in Australia, but if one was to take their Landy down the the Antarctica for a quick dash to the Pole and back !!!
I could see then what the Pommy Engineers were thinking of.

I reckon that I may be able to push a copper blanking plug with a 5 mm hole drilled in it, into that bypass -- hole, through the access in the top of the tank. I will need to measure it up to see if the blanking plug diameter fits through, a thought though.

I have one radiator that has that tropical mod done, but is yet to be fitted into a vehicle.
.

[camel_landy]

FWIW - There used to be a different spec radiator available for stinking hot countries, which ran with 5x cores too (I have one fitted to my 110). Dunno if there was a different sized bypass hole...

M

[lokka]

I had this pointed out to me about 2 years back this easter coming when I had the reco done on the motor in the D1

The guy at the rad shop wanted $550 to recore my rad and seal up the baffle plate he even said the same thing about the pomms WTF were they thinking sending landys here with a rad like that

He also said that this is why they build up with crud so easy as theres not enough flow through the core

Me being a bit tight on cash at the time opted for the cheaper replacement rad from the UK about $170 at the time landed and I thought that was not bad and it has a blanked baffle also alloy core and plastic tanks

This rad has been great but I keep a watchfull eye on both my temp gauges and just recently I did a run to dubbo on a 40deg day towing my box trailer running the AC was a on and off task as the temp would rise I would switch back to just the fan then run the ac for a bit then off again

So the little alloy core jobbie is not cutting the mustard so to speak when pushed so I am in the process of building an all alloy replacement with a localy sourced core and fabricated tanks I am in the process of working out the oil cooler and I am looking at using an aftermarket external cooler for mine and I am going to make some with internal coolers as well so they are a direct replacement

I will post up some more info over the next few weeks on how I am going with the rads and I will also put a post in the vendor section when I have a few available and they will be better priced than the others available :cool:

[isuzurover]

I had this pointed out to me about 2 years back this easter coming when I had the reco done on the motor in the D1

The guy at the rad shop wanted $550 to recore my rad and seal up the baffle plate he even said the same thing about the pomms WTF were they thinking sending landys here with a rad like that

He also said that this is why they build up with crud so easy as theres not enough flow through the core

Me being a bit tight on cash at the time opted for the cheaper replacement rad from the UK about $170 at the time landed and I thought that was not bad and it has a blanked baffle also alloy core and plastic tanks

This rad has been great but I keep a watchfull eye on both my temp gauges and just recently I did a run to dubbo on a 40deg day towing my box trailer running the AC was a on and off task as the temp would rise I would switch back to just the fan then run the ac for a bit then off again

So the little alloy core jobbie is not cutting the mustard so to speak when pushed so I am in the process of building an all alloy replacement with a localy sourced core and fabricated tanks I am in the process of working out the oil cooler and I am looking at using an aftermarket external cooler for mine and I am going to make some with internal coolers as well so they are a direct replacement

I will post up some more info over the next few weeks on how I am going with the rads and I will also put a post in the vendor section when I have a few available and they will be better priced than the others available :cool:


Personally I would not fit an all alloy radiator to a land rover used offroad.

[lokka]

Personally I would not fit an all alloy radiator to a land rover used offroad.
Ok I have heard plenty of for and against and I know the copper rads take some beating but so do the new tech alloy rads.
A lot of alloy rad cores are made in china and this has caused plenty of against/reasons not to use them as they are poorly made and I have repaired these types and personally would not use one same goes for the cheap inter coolers from china.
Ben what are your reasons against alloy rads ? have you seen a good quality alloy rad fail ? I am looking to use ADRAD cores from QLD and have seen these cop plenty of dirt track abuse and take it well.
PWR make good cores as well and I have done mods to PWR rads and have seen them used on dirt track as well with no issues.

[edddo]

I have just bought a new copper core rad from a very reputable seller for my 300tdi and was planning to do the tropical mod before fitting it.
But when I look down the filler plug ( non oil cooler side) I can see no hole, just a plate.
Does this mean the tropical mod is already done?
Seems to be so - which is good.

[edddo]

...note this rad is for a disco 1, assume they are the same config as the defers.

[Judo]

My original disco1 radiator definitely had the hole.

A new radiator today is unlikely to be an exact replica of the OEM from the 90’s though? I feel it would be a win if you’ve got one without the hole!

[rick130]

Probably should still have a small bleed, just not the 10c sized hole that was in the originals!

[edddo]

no, nothing visible at all..

[AK83]

My D1's has the (10c) hole too.
Same with the Aluminium rad I've been wanting to fit for about 2 years now too.

My understanding of the D1/Defer rad setup is that they're entirely interchangeable .. that is the whole assembly(IC and all)

[Robmacca]

Ok I have heard plenty of for and against and I know the copper rads take some beating but so do the new tech alloy rads.
A lot of alloy rad cores are made in china and this has caused plenty of against/reasons not to use them as they are poorly made and I have repaired these types and personally would not use one same goes for the cheap inter coolers from china.
Ben what are your reasons against alloy rads ? have you seen a good quality alloy rad fail ? I am looking to use ADRAD cores from QLD and have seen these cop plenty of dirt track abuse and take it well.
PWR make good cores as well and I have done mods to PWR rads and have seen them used on dirt track as well with no issues.

For me personally, I wouldn't touch a PWR Radiator. The PUMA that I bought early this year was on its second H/D PWR Radiator. The previous owner had one fitted some 12+mths earlier and about a few mths before me buying it he said the radiator developed a leak. He had it completely checked out for any sort of electrosis but all was clear and PWR fitted a new and apparently a bettter H/D Radiator.
Well, after a few months from when I bought it, I noticed that this "new extra H/D" radiator was leaking again. So, didn't stuff about and just ordered/fitted OEM radiator. We don't really tow atm, so it should do for the time being. Will look at seeing if the PWR radiator is worth fixing of not. The local mechanics told me that they no longer install PWR radiators into Defenders due to the recalls that were having (ie: leaks)