Outer Limits 4x4 Board

I have bought a aftermarket alloy radiator which claim to have a 30% better cooling then the factory radiator..

Now i have not installed it yet because i want to change or remove the aircondensor sitting in front of the radiator, but was thinking of removing the clutch fan and using either one big thermo fan/ duel fans.

Has anyone changed to this and have better cooling then the clutch fan.

I know it has been asked before but am curious to know why a thermo fan is not as effective as the clutch fan when a thermo seems more effective.

Give me an idea of what you guys have used and if it helped or not.

Cheers
Brad

When I had my hilux I went the other way for better cooling. I was running one large thermo and switched to the factory engine fan and shroud and found it helped a bit. I never noticed any loss of power either.

brad 93hilux wrote: I know it has been asked before but am curious to know why a thermo fan is not as effective as the clutch fan when a thermo seems more effective.

You will find this is because most thermos don't have a properly designed shroud.

I was thinking of maybe using a au falcon shroud and thermos and just using sheetmetal to encase the outside edges where the thermos overhang the radiator so it is sucking air through the radiator and not sucking air outside the radiator...

Not sure if that will work though

if you make ashroud as you say it should help alot, i have a vt commodore dual thermo with the fans built into the shroud like the falcon ones on my 60, a bit of modification with a grinder and a flap of rubber and seals up pretty good and pulls a fair bit of air through. the other thing with dual fans is you can have them on idividual switches so u can just run one while getting around town if u want then 2 when playing off road.

yeh thats simmiliar to what i was thinking but was asking the question to see what other people have used...

Surely there has been a few people that has played with thermo's and got a good/ bad outcome?

I tried the thermo fan thing and thought I had it right, Until I started to do some steep slow off road, Temps went sky high. Put the original clutch fan on and now no problems.

would have to also agree with the previous post had a gq 4.2 petrol patrol with 2 x 14inch fans on it and when i did steep off road work they just would not keep up , even when set to run all the time .. pulled them out and put the standard fan back on and no probs again ..

you have to compare the air the electric fans pull through the radiator compared to an engine fan at driving rpm etc 2500 rpm. if you hold the engine at 2500 rpm with the bonnet open you'll find there is heaps more air flow with the engine fan than electric fans can put out .

also noticed no difference with power or economy with electric fans or engine fan

just what i found from my experience .

yeh cheers thats exactly what i was looking to find out.....

Thanks guys

Just a quick question for you chaps who were unsuccessful with the electric fan setups, what type/brand of fan unit were you using?

hi brad, i have put duel thermo fans into my 80 series after the original fluid drive coupling didnt work so good.and i had overheating probs with it. i used the duel fans out of a nissan maxima the have duel speed and i have a switch to either have them off, both on low or both on high, turning them off for watercrossing is great for stopping water spaying all over the motor. only prob i had was forgetting to turn them back on after creekcrossings, the can be set up with a thermo switch to do all that automatically thou. never had any drama's doing hillclimbs on 30 degree days... the best thing was that the fans bolted to the original mounts, may not be the case in the hilux,,

oh and the fans only cost me $35 when they wanted $110 for an au falcon 1

brad 93hilux wrote:I have bought a aftermarket alloy radiator which claim to have a 30% better cooling then the factory radiator..

Now i have not installed it yet because i want to change or remove the aircondensor sitting in front of the radiator, but was thinking of removing the clutch fan and using either one big thermo fan/ duel fans.

Has anyone changed to this and have better cooling then the clutch fan.

I know it has been asked before but am curious to know why a thermo fan is not as effective as the clutch fan when a thermo seems more effective.

Give me an idea of what you guys have used and if it helped or not.

Cheers
Brad

Still struggling with overheating mate?

Definately stay with the viscous clutch fan. They move a shiteload of air.
Has it got plenty of fluid in the hub?
I figured out my heating problems, top mount intercooler and a better thermostat.

yeh, i think it is a airflow thing....

The 2004 model viscous fan got pulled apart during the week and put another 2 tubes of silicon oil in it(was already full), also removed the aftermarket copper radiator and installed a larger alloy one...

Still no change

Going in tomorrow to get the aircon regassed (been disconnected since the engine change)... so i bought 2 7" thermo fans and am getting the airconditioning place to replace the air condensor with a new one and put the two small thermos in front and help push air through..

When i removed the radiator i could not see through the air condensor core fins... all blocked and fins are all bent.. So hoping this will help

If not the intercooler and the oil cooler will be next

Brad

Its my truck not the engine i think as the engine never overheated when it was in the 2004 body... but i did put my turbo on it.

the best thing to dop is grab twin thermos from a ba falcon set one to come on when car start and one higher up the temp range works great run on my turbo intercoolered t/d 80 doesnt over heat anymore and better off road as pulls alot more air in at idal cheers

What or how is the best way to test and see if the clutch fan is engaging.

I'd be curius to know if you guys who havent had thermos work for you, have you had a decent shroud on them?
I have a set of AU fans I have modified to put on my 80series, just not convinced which way to go yet.

hi i just removed my direct fan and put two 10 inch thermos in and went backwards? got 20 degree hotter at normal operating temp ? so i removed one of them and kept one and put a switch on it to cut in automaticly at about 85 deg and also put back the direct fan...and everything is all good..

does anyone know what temp a 258 v8 should be sitting around ?is 70 to 80 deg too cool?

Around the city mine sits around 85 degrees (but air temps are low) but on the highway on the hills it will easily hit 115degrees (unloaded with cool air temp and egts around 300-350degrees max), but this is not over heating, the temp on the factory temp gauge is only starting to move at 115 and by 120 degrees it is 3/4.

I never let it go past 120 degrees...

Going to stick with the clutch fan but the aircon place that was gonna strap the 2 - 7" themos to the front of the air condensor cant get my bull bar off must be the 4 big roos ive hit (must be twisted)

Guess the intercooler and oil cooler will be next

...Brad...

I think its got to do with the radiator just as much as the thermal fans. I had twin (ford) thermals on my 350. But had a big 4 core alloy radiator. Shrouded it propperly and it never ever even looked like overheating in the middle of summer, on some hard hill climbs. I dont know what cfm rating they where... But they worked a treat.

yes i too bought new radiator a three core one got custom built to my needs ( just told the guy that i do alot of low speed high revs type of work soft sand hills etc etc .....so sitting around 70 deg is good considering we havnt hit summer yet........

its commonly accepted that an engine driven fan takes about 10 ish HP or 7ish KW to drive. thats a 7kw thermo you would need to match it or thereabouts.

7000w/12v = 583A
following this logic, a thermo at 20-50A (up to 600w) will not come close to an engine driven fan.

there other variables like fan efficiency and shrouding, but i've posted this to open some eyes.