HDJ79 radiator in HJ75

[ozcrusier]

My radiator in the hj75 is stuffed and needs a new core after some homework on this forum I'm thinking of replacing with the larger hdj79 radiator in brass/copper. I know I will need to move the top tank inlet over to the right hand side or run my old top tank if it fits.
Has anyone done this to there early 70 series.

 

[ozcrusier]

So no one tried fitting the larger hdj79 radiator in there early cruisers. I think it's a must do for turbo 2h landcruisers.

 

[coldtaco]

nope, but I did notice that if my egt's stay in the 900F and higher range for any amount of time the water temp starts rising, which kind of can make it difficult climbing long uphill grades if encountered.

 

[ozcrusier]

I'm keen to try the adrad hdj79 radiator but at $650 a pop I don't want to get it wrong.

 

[AussieHJCruza]

I don't know about the fitting question, but I can say that ADRAD make a nice product. I've been very happy with the 3 core Copper/Brass I put in the 80.

 

[roscoFJ73]

Cant you just use some imaginative re routing of the radiator hoses?

 

[AussieHJCruza]

Why not give ADRAD a call and see if they'd make you one that suits?

 

[ozcrusier]

It's not the plumping that worries me rosco but the fitment issue $650 a lot of coin to me if it don't fit.

 

[hotgemini]

I've got a copper brass HDJ79 radiator in my BJ74. Top hose is in the right place, bottom hose I have a 90 degree elbow brazed on and then a cross-over in radiator hose running back to the passengers side.

Had the shroud modified to cover the extra height.

 

[ozcrusier]

Well that's good news hotgemini was it a plug and play fit and just the plumbing and shroud that needed the mods.

 

[ozcrusier]

I just had a interesting talk with adrad technical support regarding my radiator questions with the 12ht engine.
There advice is to run a hj75 heavy duty 4 core unit but install a cross over pipe inside the top tank of the radiator. The problem with the 2h and 12ht radiator is having both inlet and outlet on the same side causes most of the coolant to only flow through half the radiator by installing the crossover pipe the full radiator gets used.

 

[ozcrusier]

If your 70 series 2h/12ht truck has no air con pump you can turn the thermostat cover to the left and use a hzj75 radiator with the top left inlet.

 

[roscoFJ73]

I thought you wanted the extra volume from the HDJ79 rad.
I put a HZJ75 rad into a FJ73 .The FJ73 would have the same body as the HJ75. The HZJ75 rad should fit in the same place as a HZJ79 and a HDJ79 .
Cant go wrong

 

[ozcrusier]

Rosco
It did go wrong mate the air conditioning pump is in the way so I cant run the hdj79 hzj75 type radiator with out the same modification.
The shop doing the work told me it's the second last 3/4 blank in the country and is the best way to go as it's fully Australian built and will last years.

 

[coldtaco]

what did you end up with?

 

[dare]

Old topic but just putting this here for the info.

I run a HDJ79 radiator in my BJ73. I extended the shroud and to get the bottom hose to the other side I have a cut BJ73/4 lower hose going into a stainless 90° bend which then goes into a cut early HJ75 lower hose which connects to the radiator.

All the radiator mounts in narrow front, heavy duty 70 series are the same spot. All the cores are the same width, thickness varies between style/manufacturer but 4 core copper ones are 66mm. 70 series have quite small radiators compared to similar vehicles, there's just not much space with that narrow front end.

Early HJ75/BJ73/BJ74 radiators have a 450mm tall core. Dunno if later BJ7x got the bigger core later on, you can buy them aftermarket.

Late HJ75 and HZJ75/8/9 has a 500mm tall core.

HDJ78/9 have a 560mm tall core. Many HZJ78/9s have been fitted with these.

Something to consider is the HDJ79 radiator sticks down below the chassis, making up a bash plate would be a wise investment.

I ran a fully welded alloy eBay one which cooled fantastically, the temps never got above 82°c (thermostat temp) even thrashing through the dunes on a hot day. 3 of the 4 brackets broke off it on a corrugated road so now I have an OEX (repco) 4 row copper/brass which doesn't cool very well (I'm only running a non-turbo 3B in a relatively light car!) and is poor quality.

I can't afford the $1k price tag for a PWR or Terrain Tamer alloy radiator so I'm thinking of grabbing another eBay one and getting the mounts braced up.

 

[coldtaco]

Dare, been following your thread, but thanks for the rundown on the different sizes. Come spring I will start my search again for a better radiator.

 

[ozcrusier]

No problems with my modified Adrad radiator this summer truck has been running as cool cucumber no matter what the outside temp is it's the best investment I made on the old girl for engine longevity.

 

[coldtaco]

No problems with my modified Adrad radiator this summer truck has been running as cool cucumber no matter what the outside temp is it's the best investment I made on the old girl for engine longevity.

What model radiator did you end up with?

 

[ozcrusier]

Adrad 4 core blank with the top tank removed and cross over pipe fitted. It's the same size as the standard Landcruiser radiator.