Outer Limits 4x4 Board

Just noticed one of the straps on my radiator has cracked off one side. Am going to get it fixed next week, but just thought I'd see wether it would be worth getting it converted to a dual pass radiator while he's got it?

Heres a pic of my current setup, on the right is the old std. V6 radiator, and on the left is the new one I installed with the Lexus V8. It has worked pretty good, and has kept it cool under just about all conditions, except when fully loaded in soft sand and slower speeds.



Would there be any benefit of converting my current radiator into a dual pass setup cooling wise?

Any info would be great.

Not really, they can work better but your losing a lot off efficiency with that shitty fan, you should either look at an engine driven fan with a shroud or a custom shroud to suit that electric fan.

This is the sort of thing that plagues many modded cars, people remove engine fan and shroud and fit big ass electric fan to make more horsepower, which also pulls less air.

EF/EL/AU fans are different as they have the shroud and flow stupid amounts of air so anyone running these save your flaming. Looking at your pic it seems the AU's wont fit so you might look at other things.

I agree that the fan isn't working to its best efficiency. There is no room for an engine driven fan, nor is there room to have the fan mounted on the engine side of the radiator. I have to run the fan on the front, hence the no shroud etc......should have mentioned that in my fist post, sorry.

One thing that may help is if I go to a dual pass radiator, it frees up a bit of room on the back of the radiator, as I will no longer have a long hose coming up from the bottom of the radiator to the top of the motor. It 'may' hopefully free up enough room to get a fan on back of the radiator.

NutterGQ is 100 % right, if you have that many space limitations I'd be considering a full alloy Rad as they exhibit better heat dissapation characteristics. It would be better to sort a shroud though, your fan could be better if you made a shroud for it, at least it would draw air through the whole radiator not just where the fan is.
Joel

PGS 4WD wrote:NutterGQ is 100 % right, if you have that many space limitations I'd be considering a full alloy Rad as they exhibit better heat dissapation characteristics. It would be better to sort a shroud though, your fan could be better if you made a shroud for it, at least it would draw air through the whole radiator not just where the fan is.
Joel

I am prepared to get a alloy radiator later this year, just not at the moment. Thought this may be worth trying before going to alloy but amd since the radiator will be out.

As for the shroud, if the fan is pushing air through the radiator, does a shroud still work? I thought it would make things worse? specially on the highway etc. since the shroud would block off a lot of the airflow?

You need the fan on the inside to utilize a shroud. Is there no fan in the engine bay?? Thats fighting a loosing battle.
joel

PGS 4WD wrote:You need the fan on the inside to utilize a shroud. Is there no fan in the engine bay?? Thats fighting a loosing battle.
joel

Nope, shit all room on the engine side of the radiator to fit a fan. Its a common problem with fitting the Lexus V8's into the small hilux engine bay.

got any vents in the hood to let out sum of the hot air?

Yeah, forward facing Patrol Bonnet scoop....which is proabbly doing more harm then good.

I thought about trying to turn it around to see if that made things any better.

You don't need a shroud if you have a fan in front of the rad; you just need to make sure that the fan surround is hard up against the radiator... ie, that the air the fan is pushing can't get out sideways before it goes through the radiator. You definitely DON'T want a shroud if you have a front-mounted fan.

If the fan is of good quality and a good size there is absolutely nothing wrong with this arrangement. I would just be fitting the biggest one you can find, or possibly even one big and one small one if that covers more surface area of the radiator and flows more air.

The fan you've got appears to be smaller than what you could fit. Your money would be better spent on a great big fan or a second fan than on a dual pass rad.

Just remember it's the area of the fan, ie two 10" fans are not nearly as good as one 20" fan.

Dave I`ve been thinking of getting a triple flow alloy rad for mine and dropping it back in the front.

Who is it using a 45 or 75 series rad?

chimpboy wrote:You don't need a shroud if you have a fan in front of the rad; you just need to make sure that the fan surround is hard up against the radiator... ie, that the air the fan is pushing can't get out sideways before it goes through the radiator. You definitely DON'T want a shroud if you have a front-mounted fan.

If the fan is of good quality and a good size there is absolutely nothing wrong with this arrangement. I would just be fitting the biggest one you can find, or possibly even one big and one small one if that covers more surface area of the radiator and flows more air? (ie. 16" on front and two 10" ones on the back)

The fan you've got appears to be smaller than what you could fit. Your money would be better spent on a great big fan or a second fan than on a dual pass rad.

Just remember it's the area of the fan, ie two 10" fans are not nearly as good as one 20" fan.

Thats a 16" ICE Thermo fan on there at the moment, and its mounted as close to the core as possible, it also has some bullshit flow figures for the size fan it is, and when you here it running you know its moving a sh!tload of air. But you are right, I probably could fit a bit bigger fan on there. If I do this dual pass thing, it will free up enough room on the back of the radiator to probably squeeze in a couple of 10" fans on the back. Which would probably work better than going to a bigger one on the front.

Guts wrote:Dave I`ve been thinking of getting a triple flow alloy rad for mine and dropping it back in the front.

Who is it using a 45 or 75 series rad?

Nemesis was running a 75 series one I think.....and has the same issues as me. His isn't as tall as mine, but is a little thicker.

I think alloy radiator will be the only fool proof cure.

TWISTY wrote:Nemesis was running a 75 series one I think.....and has the same issues as me. His isn't as tall as mine, but is a little thicker.

HAD not has

Since I went the rear mount rad I haven`t really been following the heating/cooling problems as mine cools perfect now. But I hate the look of it and want it back in the front

I am planning to get the biggest possible alloy radiator made for my 4runner Lexus conversion (thanks to info from members here). I will have to see what room I end up with but I am now planning AU twin fans between motor and radiator if I can possibly get it to fit (maybe skinnier radiator). I will wait and see when the engine is in.

Could someone please explain what dual bypass is exactly ??


Ricky

Mine is alloy dual pass and also has the twin AU thermos on it. There is very little room between the fans and the motor. The plastic capping on the back of the fans has been shaved slightly as it did hit when the motor was torqued up originally. It no longer hits and I have never had a cooling issue even with slow speed 1st low revving the crap out of it in a very hot Qld summers day. Nor has it ever gone over 100 celsius in the soft sand. Imo the lack of space is a concern but I would rather live with it to avoid the cooling issues.

Dual pass, not dual bypass, I think.

chimpboy wrote:Dual pass, not dual bypass, I think.

Oh Yeah oooooops.

But what does that mean? I am guessing the water passes through the rad twice (stands to reason).


Ricky

Its where the inlet and outlet hoses are on the same side and the tank is seperated in the middle, causing the water to travel through the top half of the rad. then in the side tank, then through thw bottom half

Work well, problem is when you block 1 core, you loose the efficiency of 2

cloughy wrote:Work well, problem is when you block 1 core, you loose the efficiency of 2

The other issue is if the Bafel on the hose tank is not fitted correctly and allows flow through it you will cook the engine as fast as if you had no radiator at all.

RUFF wrote:

cloughy wrote:Work well, problem is when you block 1 core, you loose the efficiency of 2

The other issue is if the Bafel on the hose tank is not fitted correctly and allows flow through it you will cook the engine as fast as if you had no radiator at all.

Very true

If you get a Rad made can you move it forward to make room for a fan and shroud behind??
Joel

PGS 4WD wrote:If you get a Rad made can you move it forward to make room for a fan and shroud behind??
Joel

x2. Can't you fit the rad on the front of the support panel and rejig the grille?

slosh wrote:

PGS 4WD wrote:If you get a Rad made can you move it forward to make room for a fan and shroud behind??
Joel

x2. Can't you fit the rad on the front of the support panel and rejig the grille?

I was thinking this too.

Also boof......

I understand the thickness issues between rad and engine, but what about the width of the AU fans? I was checking them out and they are a VERY wide unit (650mm wide verses current 530mm). Did you have any issues? Was there much to modify including getting the radiator made that wide as well?


Ricky

Hey Dave have seen a car from factory with a pusher fan on the front of a radiator, that had a shroud.

The fan is a high output multi speed unit.

Also 4runner rick on pirate ran a shrouded fan on the front of his 7mge, converted 4runner. This fixed a overheating problem he had.

Give the shrould a go and let us know.

Matt

rixrunner wrote:

slosh wrote:

PGS 4WD wrote:If you get a Rad made can you move it forward to make room for a fan and shroud behind??
Joel

x2. Can't you fit the rad on the front of the support panel and rejig the grille?

I was thinking this too.

Also boof......

I understand the thickness issues between rad and engine, but what about the width of the AU fans? I was checking them out and they are a VERY wide unit (650mm wide verses current 530mm). Did you have any issues? Was there much to modify including getting the radiator made that wide as well?


Ricky

To be honest Id have to check on the actual width of my rad I cant remember it I do know the fans shroud is a little wider but not enough to cause a problem.

Chimpboy is right about not having a shroud with a front mounted fan.

When the fan clutch died on my Rodeo I had 14" electric fan (ex OEM BMW Siemens brand S blade) handy so I modded the grill a bit and fitted it as close as I could to the a/c condensor.
It worked pretty well with the factory shroud still on except on hot days under load on the highways. (All other conditions it was fine)

I took the factory shroud off to see if it improved cooling on the long hot highway trips an it did to a degree
I think a front mount fan still needs shrouding on the front of the radiator/condensor and level with the front of the fan to collect as much air as possible so the fan isn't pushing air out the sides and away from the radiator area, which is what was happening to a degree on mine.

Mind you that was sitting still with the fan at full bore, I just had a manual switch to turn it on when needed.

cheers, sudso