GU radiator - Alloy or OEM

[Beucam]

While setting up my Dawes & needle valve on Monday, bumped the radiator overflow, 13mm outlet. This "fell off".
The radiator has a plastic top, and as far as i can ascertain, it is the original - now 11 years old. Not bad i suppose.

Have looked around and replacement can be a mine field - need to do lots of homework.
Looked on e-bay, found loads of Alloy. Did some research on these traders and have narrowed the list down to a few, who seem to have reasonable feedback.

Spoke with some radiator repair shops and they are really not keen on alloy.
There is a company in Brisbane on North side called ARE, who have done a lot of R&D using Alloy radiators.
Currently my thinking is that most performance vehicles (sure my Patrol is not racing around a track) have switched over to Alloy radiators. There must be some advantage in the cooling transfer and light weighting on offer from these Alloy radiators.

Are there any members who have installed these Alloy radiators and what is there feedback.
Looking forward to some great convers on this topic.

[macca86]

Better to stay with copper brass standard radiators for your 4wd easier to get repaired cheaper mire durable and less cracking with metal fatuige plus alloy can suffer electrolysis problems and fail I'm lead to believe

[nissannewby]

I installed an Adrad aluminium radiator 2 years ago it's still going great with no signs of corrosion or electrolysis. There is an unnecessary fear out about ally rads. Like any other part of your vehicle your cooling system requires appropriate maintenance. The copper brass items are a little more forgiving on poor maintenance.

Yes ally are harder to repair but if looked after will give years of trouble free running.

Cost vs reliability mate the genuine items are hard to go by. Like you have seen first hand 11yrs out of your standard one. Pricing wise they are in the middle of a quality brass/copper unit and a quality ally unit.

[Alitis007]

If you have a search on the forum this subject has been covered before. Main problem with ally radiators is trying to control stray currents and electrolysis, earth straps and coolant for aluminium blocks is a must. Any half decent radiator shop will try steer you clear of an ally radiator because they look better than they cool which i have first hand experience with not to mention serviceability is nill. Plastic tanks and ally cores is a winner for manufactures because they last and also are cheap to make where copper/brass units are made from more durable material, look at old holdens and fords for eg their radiators can last upto 30years with proper maintenance.

[nissannewby]

because they look better than they cool.
Plastic tanks and ally cores is a winner for manufactures

This is a little contradictory. There cooling properties can't be all that bad if pretty much every car manufacturer is utilizing an aluminium core.

No matter which way you choose though. The word that matters most here is "MAINTENANCE".

[Alitis007]

This is a little contradictory. There cooling properties can't be all that bad if pretty much every car manufacturer is utilizing an aluminium core. No matter which way you choose though. The word that matters most here is "MAINTENANCE".
You an i always get into a debate about this matter hey Matty!? Your right, maintenance is the key for longevity of everything but let look at operation for a minute. OEM radiators do have aluminium cores but have plastic tanks. Heat soak doesn't affect the plastic as much as aluminium tanks coz plastic heats up and cools faster than metal. Some real world experience i've had is with my rx which i want to have a certain water temp for performance reasons, to monitor the water temp i use a thermo fan controller with a sender on the top of thermostat housing and the coolant temp sender on the back of the motor which i read thru the aftermarket ecu hand controller. The oem rad was ally core plastic tanks and a 38mm core the temp was more stable under moderate and heavy driving but also cooled faster while coasting, now i run a ally core and ally tank rad also with a 38mm core ( coz i had no other option at the time ) the water temp rises faster and is less stable during all types of driving unless ambient air temp is around 10 - 14*c. The only thing different in my setup is the radiator, both had same amount of airflow and the same thermo fans that produce 3,000cfm, both radiators have the same size tube and fin design and the same id in the tubes but NOT is higher with the ally rad.

Without mentioning how much trouble i went thru making the ally rad last longer than a month before it leaked, what do you think would cause such a big variation with the cooling effect?? I think its the tank material and also a square design unlike the curved plastic design.

[nissannewby]

Without mentioning how much trouble i went thru making the ally rad last longer than a month before it leaked, what do you think would cause such a big variation with the cooling effect?? I think its the tank material and also a square design unlike the curved plastic design.

Maybe the quality of the unit you purchased is the defining factor here. My experience has been quite the opposite to yours mate. Cooling has never really been an issue for me and even less so with the radiator but any radiator with the same increase in size will help. I haven't lost a drop out of mine since installing and do regular checks for electrolysis and all comes up fine.

Aluminium is actually better at heat exchange and dissipation. What you seem to be referring to as heat soak is actually heat exchange. The idea of the radiator is to draw the heat from the fluid. Plastic is an insulator hence why it will be cooler than aluminum. If it wasn't any good for cooling then why are all your top knotch intercoolers made from aluminum?? It's simple really ally is better for heat transfer. Intercoolers use exactly the same concept. Again I can't comment on why yours was so bad maybe quality as suggested. Temp fluctuations aren't caused by a radiator unless you can't get enough air or water through it of course.

[threedogs]

That outlet you broke off can be repaired quite easily you need a 1/4bsp hose barb fitting,
rough up the brass thread and use Teflon tape. mine been repaired like that for 2 years now with no drama
Overweight mechanic lent on it lol

[Alitis007]

Maybe the quality of the unit you purchased is the defining factor here. My experience has been quite the opposite to yours mate. Cooling has never really been an issue for me and even less so with the radiator but any radiator with the same increase in size will help. I haven't lost a drop out of mine since installing and do regular checks for electrolysis and all comes up fine. Aluminium is actually better at heat exchange and dissipation. What you seem to be referring to as heat soak is actually heat exchange. The idea of the radiator is to draw the heat from the fluid. Plastic is an insulator hence why it will be cooler than aluminum. If it wasn't any good for cooling then why are all your top knotch intercoolers made from aluminum?? It's simple really ally is better for heat transfer. Intercoolers use exactly the same concept. Again I can't comment on why yours was so bad maybe quality as suggested. Temp fluctuations aren't caused by a radiator unless you can't get enough air or water through it of course.

At the time it was in the middle of the market and from what i found out it was rebranded by a local manufacturer ( which i wont mention coz i don't like him coz he's an arse lol) and sold as that well know brand, but i used the same manufacturers intercooler on the rx and on my vl but in bar and plate and never had a problem. Now when i said the temp rises its not the actual needle that moves rather the digital temps i'm reading from the hand controller and thermo fan controller, even on the gu where gauge shows NOT is from 70*c up to 110*c so you wont see any movement from that but on the digital read out i can get the temp to stay between 80 - 88*c where i want it to be with the oem radiator. Under heavy load the temp will rise to 90 but stay in the 80's during coasting but with the ally unit its around 100*c under load and 90 during coasting. Imo i could only fault the tank design as the 3,000cfm from the thermo's was the same. Another performance workshop i knew had a similar problem with some pwr radiators in some of their cars but i never got around to finding out what the issue was ( when you knock back a job offer you loose any connection you make )


Back to the OP i will recommend to you what i recommend to all my customers and that is, a standard replacement (ally core plastic tank ) is your cheapest and easier option, it'll go in without any hassle and if you buy an Adrad or any other reputable manufacturer they'll offer a 3 year warranty because they stand by their quality controlled products. If you want a larger rad because you will be towing or putting the car under heavy loads for extended periods and you want more water to keep the motor cool try and get a copper/brass or a alluminium radiator but be aware in some cases you might need to modify your fan cowling to make a thicker radiator fit also too thick and it will affect airflow thru the heat sink and not do its job. Some larger radiators ( mostly the ally ones i have seen) have a conditional warranty which is you need to run a certain type of coolant and RA% and you need to flush it every 12 months regardless of km's

[Beucam]

Threedogs,

Yesterday afternoon, found a piece of 1/2" copper pipe, cut a piece about 2" long. Used a 12.5mm drill, drilled open the plastic hole, and glued this piece of copper pipe in.
I have found this amazing super glue with filler called "Rapid fix" at our local bolts dealer.
It is really glued well and will see how she lasts.

Gives me some more time to think , read and digest about ally radiators.....