Rear mount radiator

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kbushnz
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Rear mount radiator

Postby kbushnz » Mon Oct 29, 2018 9:41 am

After some info / advice.. (thinking out loud)

Setup a rear mount rad for my Prado bum chop. Running a large Nissan GU Radiator and Au falcon fans.
Getting an issue with airflow...
Fans kick in and out all the time and basically control the temps in the engine hahah Poor thermostat must be pretty much open the whole time.

Think the issue is lack of clean airflow esp at highway speeds.
What have others done to help it...?
Was thinking of wiring the fans for 2 speed....)
On all the time at low speed (simulate vehicle moving or engine driven fan moving air) then kick in the fast speed when it needs the extra cooling.
Its not a daily driver but road legal weekend toy....

Will also look at making some wings to deflect redirect airflow around the rear chop...

Fire away team...

Calvin
Cheers Calvin
KZJ78 Landcruiser Prado...

mudtroll
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Re: Rear mount radiator

Postby mudtroll » Tue Oct 30, 2018 5:01 pm

Might need a air diverter to get flow over the fans/radiator. A piece of perspex bolted to the rear cage protruding above the roof line might do it.

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mudlva
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Re: Rear mount radiator

Postby mudlva » Tue Oct 30, 2018 7:09 pm

kricky mate you are asking for lots here ah.

you need to do wind tests to see what the air is doing at different speeds. i know a bloke a while back who spent ages driving at different speed with rags tied to the back on tight wire grid type pattern to see where best placement of rad would be. as you already mounted yours then potentially go backwards from there. majority of fans only work up to 40ish kph so any speed after that needs to be driven in. ie thats why they are at the front.
so as mudtroll suggested. is to divert with a solid type of sheeting. personally i think you are going to be disappointed with results.

couple of alternative options are
mount a extra rad in front of engine bay that you can fully cover when in bush
extractor vents at rear of bonnet to allow hot air out easier. as the motor does get a degree of air cooling when on the open road

worst case is to remount rad higher and further back to pick up cleaner air flow with some from of cowling to help push s much air as possible into the rad surface

or remove windscreen :shock: :shock: :lol:

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kbushnz
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Re: Rear mount radiator

Postby kbushnz » Wed Oct 31, 2018 6:29 am

Cheers Guys
I have had a play with a run to work and back, turned the fans on the whole time..
Engine temp settled down and the rad outlet dropped to a steady 60 ish...
And if i stop in traffic it will plummet to 30.....
The rad is more than capable of cooling her down its all about airflow now lol...
Yeah will look at making a couple of ducts for the sides and scoop some air in.
If I have to redesign the rear a bit... so be it....

Thought about another rad out front, just more plumbing to contend with...
Ah the fun of doing mods....
Cheers Calvin
KZJ78 Landcruiser Prado...

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kbushnz
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Location: Massey, Auckland

Re: Rear mount radiator

Postby kbushnz » Sat Nov 03, 2018 7:47 am

Well I have had a long hard think.... And for what I want to use this truck for the rear rad is not going to do it for me,.
Spent the whole day with cardboard ducts and put on 100 ks of motor way running...Tweaking, moving etc etc
With the area I have to work with its not ideal. Now if the truck was a trailer queen it would be sweet...
Works just fine off road and low speed....
But that's not what I want.... Its use has changed and I need to tow with it ....
So back out the front goes the original radiator setup..

Soon I will have a near new Nissan alloy radiator (thick one) and Au falcon fans with custom fan shroud for sale.... lol..

Thanks for the advice and help...

See you on the trails....
Cheers Calvin
KZJ78 Landcruiser Prado...

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mudlva
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Re: Rear mount radiator

Postby mudlva » Sat Nov 03, 2018 5:25 pm

prob the best esp' now you are towing.

ran a good engine prop fan as well. leckys cant keep up with high hard usage.

in my 70 with v8 sbc the engine prop fan took 15d+ off the temps compared to twin 16" c.d. fans

see you at manukau w.c.?

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kbushnz
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Re: Rear mount radiator

Postby kbushnz » Sun Nov 04, 2018 7:13 am

yeah the factory engine driven fan and radiator was excellent... so its all going back in.
I should be going to manukau... for a looksie...
Wont be competing winch truck still in bits..
Cheers Calvin
KZJ78 Landcruiser Prado...

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mudlva
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Re: Rear mount radiator

Postby mudlva » Sun Nov 04, 2018 10:32 am

Im competeing (or should be said attempting). Will stop and chat if time allows....

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