all thermo fans are rubbish. clutch fans are much better unless you spend donkeys years making a perfect seal fan shroud. plus then you have the joys of all the electrical faults that go with them and the crappy 55A alternators that the VK's come out stock with. stick a good stereo in, headlights, heater and wipers and you get a flat battery. fun fun fun. plus all the joys of figuring out why your engine wont rev past 4K rpm when you have your heater/wipers going.
its not as easy as just sticking a new fan/shroud on. you will need 5mm spacers for the waterpump to retain its pulley. they all need to be the same weight so you cant just grab random washers from your bolts bucket. an unbalanced pump will leak eventually.
then you need to really put some time and effort into getting the shroud to seal 100%. it will need to cover the ENTIRE radiator and suck air evenly through or itll get hotspots which will eventually leak. it means fitting the shroud, fitting the radiator, taking it off, adding material, deleting material, fitting the shroud, fitting the radiator, taking it off (repeat).
THEN you need to change your alternator to handle the draw of two thermo fans. and yes, they draw a LOT of power. you can hookup a thermo switch, but they are not cheap and look a little bit ugly imo, but i guess it depends on how much planning you put into it. the only one i have seen is where the owner drilled a hole in the top of the thermostat housing and ran a wire. looked horrible. i would never do it. plus the fact that the majority of time itll spend switched on is at idle when your volts are at their lowest and when you will have the most trouble.
THEN you will need to run adequate wires and relays to it. i ran 2 single 16guage wires to power both of mine (one + one -) which i thought would be ample. i was wrong. after scratching my head for about 4 months i decided to run an addition wire to each (so 4 in total) and the fans instantly increased in speed, while hooking it up i noticed the single 30a fuse holder had completely melted, the fuse was fine, the holder was toast so i hooked up a 20A fuse to each wire and added an additional relay, so each fan now is completelty independant. running direct from the battery and comes on with ingnition 'on'.
so if your in the mood to go through all that bullshit, then go right ahead. just remember that there will be very little to no difference in power, and engine temperatures will increase.
I read most of your posts Ari and they are pretty well thought out for the most part.
I disagree with what you say about the thermos.... a clutch fan is always going to beat a **** instal of a thermo fan.
however if you do the electrics properly, not just twisting wires together and a flick of solder and electrical tape like most P platers who know ####all... (ive seen enough of their attempts in the wreckers with P plates still on the written of car), then it works.
as for the 55A alternator, mine ran a 120A unit with a sensor. yes its some money, but doing a job properly is never cheap, another fact lost on some of the people who post on these forums who do mods more for looks and the sake of it rather than anything else.
Anyone who builds are serious engine wont skimp on a good alternator if its a street driven car, add 20A for each fan. more for a big stereo if thats what you're into, another 10A for a good ignition system....
of course the clutch fan will be better than thermos where someone couldnt be ####ed spending a little time and taking the time to seal up the shroud properly.... sadly some car enthusiasts are butchers instead of craftsmen.
its best to pull the radiator out of the car and fit the shroud up that way, and then drop the whole assembly back into the car.
as for the temp switch, run one out of one of the TVS ports in the front of the manifold.
as for the spacers.... once again... too lazy to think. Buy some fine thread socketheads from a bolt shop, shorten them enough so they dont foul on the waterpump snout. and use them to hold the water pump pulley on, will be kucky to cost $1.
Ari you went through all that bullshit wit melted wires etc etc because you were either given wrong info or didnt bother to do your research properly before doing the job.
course you run each fan off its own relay.
My set up runs fine and I'd back it against any clutch fan....there are blokes in the VIC chapter that meet at FG that will vouch for it.
I'm not having a go at you, I just dont agree with what you posted, esp when most of what you post on here is spot on.
This topic has been done to death.
Further research can be done on
Home of the HDT amd
GMH-Torana Website and Forums - Home
thats where I got all my info from BEFORE i did anything.