Radiator for GQ

[GQ Toy]

After a recent engine upgrade my GQ is now running hot - suprise suprise

Am investigating different radiators and as usual getting different comments depending who I talk to. Talking to one guy yesterday he suggested that the nissan std rad is quite efficient compared to aftermarket 3 core copper rad. Thinking about conductivity of Cu and Al it makes some sort of sense.

I am quite prepared to spend money on a fix, but only if it will do the job.

Vehicle now has an 03 4.2TDi motor, runs 33's, tows camper and I play on the beach and in dunes. So far it does not get hot (above 3/4) during normal running only when working hard, soon as I ease off the temp drops.

What are peoples experiences with aftermarket radiators, should I just try to fit a GU radiator or do I go for the twin radiator setup.
Any comments, suggestions welcomed
Cheers
Brad

[DanielS]

hey man, im looking into a PWR radiator for my GQ. they are aluminium unit and offer really good cooling...look trick aswell

[GQ Toy]

Am looking at one of them as well, but for the cost I want to make sure it is going to do the job

[DanielS]

from other people i have talked to they seem to do the job, Cass Jones used one in he's turbo petrol 4.5 GQ in the OBC last year and said it worked well. Also have a talk to Toughnut hes running one in his GU at the moment.

[GQ Toy]

Cheers I will do that

[toughnut]

Yeah it ran awsome in the OBC. I also have a twin thermo setup as well cause although you can just bolt it in I wasn't happy how close the engine fan was to the new shiny radiator. I also switch them off in deep water.

Don't have a decent pic of the radiator in the truck but it bolts straight in with no modifications at all. One thing I will say is check that your hoses are well clear and can't bump or rub on your pulleys after it goes in. The radiator for my water/air intercooler is PWR as well as the intercooler itself.

[awill4x4]

Here's a pic of the one I built for my GQ. It's using a K&J (PWR) core for an F100/Bronco. The core is about 30-40mm narrower than standard but I made the endtanks larger each side to make up the difference. The height is the same as standard. The core is 57mm thick with 2 rows of 26mm tubes. It works a treat and doesn't overheat under load towing our caravan which we were experiencing prior to building this radiator. One problem I have had is that the back of the core is now closer to the fan and on one river crossing the fan just slightly hit the back of the core without doing any damage to the radiator luckily.
I've got a pair of AU Falcon thermo fans ready to install at some stage in the future to stop that problem occurring again.
In hindsight, I wouldn't bother installing the auto trans coolers in the tanks and just rely on the auxilliary cooler mounted up front and I would even consider using a custom core of 1 single 40mm tube as these seem to work just as well as the 57mm thick core. We built one for a competition Australian Safari GQ running a 355 stroker V8 and the 40mm thick core kept his cool without any problems.
Regards Andrew.

[toughnut]

One thing I forgot to add is to make sure you use heaps of coolant in the system even to the point of only running coolant and no water. Alloy corrodes easily if you don't use the addative. It acts a an anticorrosive.

[GQ Toy]

Cheers awill4x4 and toughnut, this is the info I was chasing.

I change coolant fairly regularly and run high levels of coolant to water

Out of curiosity how close does the fan run to the rad

[toughnut]

The PWR radiator is 20mm thicker than standard. Matt Bolger runs pretty much the same radiator with a factory fan and hasn't had a problem. I wanted to have a bit more control over it though. If I want to heat the engine up quicker on a cold day I just turn the fans off. If I go into a deep, long water crossing I also turn them off. They also suck heaps more air through than a factory engine fan without having to rev the engine, so you can sit at idle after a stage and let it cool down quicker. The only time it overheated was on a creek nav in deep soft sand and my navi left the cable damper hanging in front of the grill after a winch. Other wise it hardly moved from where it normally sits.

[GQ Toy]

Cheers Toughnut,
Reason I ask is I spaced the fan on my previous motor clser to the rad by 25mm in preparation for a supercharger (did not happen) and this only touched the rad once very lightly.

[toughnut]

Found a pic of the thermo's for ya.

[GQ Toy]

Hey Toughnut, very Would there be any difference between crossflow and vertical flow for efficiency?

[toughnut]

GQ/GU run high volume/low pressure which means it is better to have normal vertical flow radiator. It will also be a pain in the ass to bleed the air out of a cross flow system on a patrol

[Red Rover]

The other difference is in std australian model is they run coarse core, where the import one I run with a turbo, no cooling problems at all (runs on qtr) in fine core and staggered. You can get a three core where all the tube line up straight or on where they stagger the tubes. It seems to make a difference. the three core with a staggered tube is more expensive, but works better. It's the only difference I can see between them.

Cheers

[Red Rover]

Yeah it ran awsome in the OBC. I also have a twin thermo setup as well cause although you can just bolt it in I wasn't happy how close the engine fan was to the new shiny radiator. I also switch them off in deep water.

Don't have a decent pic of the radiator in the truck but it bolts straight in with no modifications at all. One thing I will say is check that your hoses are well clear and can't bump or rub on your pulleys after it goes in. The radiator for my water/air intercooler is PWR as well as the intercooler itself.

\

How does that intercooler work with it plumbed into heated water? The one I have carries a separate radiator to cool the water entering the intercooler?

[toughnut]

Thats what the last pic is. I ran out of time to complete the conversion cause the stand alone radiator hadn't arrived before I went to Outback. I've now completed the setup. I'll also be adding a 5-10 Lt water tank to it as well.

[Red Rover]

yep, i tought as much. I couldn't see how you ran two setups. therefore its a before and after shot.

How well did it work when it was plumbed to engine cooling system?

[toughnut]

It did make a small difference but when I plumbed it properly it dropped the boost on the guage by 1psi without changing anything else so it's definately working now. I'll have it back on the dyno soon to see exactly what difference it did make.

[GQ Toy]

GQ/GU run high volume/low pressure which means it is better to have normal vertical flow radiator. It will also be a pain in the ass to bleed the air out of a cross flow system on a patrol

Reason I ask is my GQ has a crossflow rad - I assume it is standard?

[MKPatrolGuy]

GQ/GU run high volume/low pressure which means it is better to have normal vertical flow radiator. It will also be a pain in the ass to bleed the air out of a cross flow system on a patrol

Reason I ask is my GQ has a crossflow rad - I assume it is standard?

Yep, crossflow is standard.

[toughnut]

GQ/GU run high volume/low pressure which means it is better to have normal vertical flow radiator. It will also be a pain in the ass to bleed the air out of a cross flow system on a patrol

Reason I ask is my GQ has a crossflow rad - I assume it is standard?

Yep, crossflow is standard.

I guess thats why its a pain to bleed the system GU's are verticle. The PWR is an alloy replica of the factory with the only design difference being the thickness. They bolt straight in with no hassels

[awill4x4]

GQ/GU run high volume/low pressure which means it is better to have normal vertical flow radiator. It will also be a pain in the ass to bleed the air out of a cross flow system on a patrol

Reason I ask is my GQ has a crossflow rad - I assume it is standard?

Yep, crossflow is standard.

I guess thats why its a pain to bleed the system GU's are verticle. The PWR is an alloy replica of the factory with the only design difference being the thickness. They bolt straight in with no hassels

That's why my custom radiator has bleed off points in both endtanks Neither factory, aftermarket or PWR put them in, or a provision for the factory shroud from PWR either

[toughnut]

On the PWR radiator I got for my GU it had all the provisions on it. Including the shroud.

[awill4x4]

On the PWR radiator I got for my GU it had all the provisions on it. Including the shroud.

Not on the GQ ones, I've seen 2 PWR ones for GQ's and neither had provision for the factory shroud.

[toughnut]

That sucks....Well not as well as if it had a shroud

[bazzle]

One thing I forgot to add is to make sure you use heaps of coolant in the system even to the point of only running coolant and no water. Alloy corrodes easily if you don't use the addative. It acts a an anticorrosive.

The more coolant over the max recommended level does not improve its anticorrosion ability. It also makes an engine run hotter as more coolant to water has less heat transfer properties.

Just check your coolant properties with a coolant meter.

Bazzle

[toughnut]

One thing I forgot to add is to make sure you use heaps of coolant in the system even to the point of only running coolant and no water. Alloy corrodes easily if you don't use the addative. It acts a an anticorrosive.

The more coolant over the max recommended level does not improve its anticorrosion ability. It also makes an engine run hotter as more coolant to water has less heat transfer properties.

Just check your coolant properties with a coolant meter.

Bazzle

This info was given to me by the guy at the radiator place I go through.

[tjgood]

Before you spend to much money, check your fluid drive for your fan. If thats not driving your fan you'll get overheating problems.

[GQ Toy]

Before you spend to much money, check your fluid drive for your fan. If thats not driving your fan you'll get overheating problems.

Has a brand new fan as the other one was destroyed in a prang. When I shut the motor down the fan stops instantly