Thermo in Vk help

[Gudgeon Pin]

hey all, have a vk calais as a toy doin few bits and pieces. runs a 5litre from vn, want to fit thermo fan. any one done this or steer me in the right direction. Want to know bout mounting and wiring. Have looked on here but can't find many vk's with injected 5, unless i'm looking in the wrong spots. Will post up car sometime after respray probably. Thanks

[VK SL 3800]

Many people fit mondeo fans as they are a close fit but just as many end up putting the big viscous units back on because the thermos cant cut it in traffic/low speeds. Nothing on the market can match the original fan for air flow. With my V6 i fitted the vp thermo fan and it has no problems keeping up, today was 40 c and it never got hotter then normal, but the V6 is much smaller and easier to cool so really you cant compare and i run a heavy duty V8 radiator as well, overkill.

[Cane_It]

Many people fit mondeo fans as they are a close fit but just as many end up putting the big viscous units back on because the thermos cant cut it in traffic/low speeds. Nothing on the market can match the original fan for air flow. With my V6 i fitted the vp thermo fan and it has no problems keeping up, today was 40 c and it never got hotter then normal, but the V6 is much smaller and easier to cool so really you cant compare and i run a heavy duty V8 radiator as well, overkill.

sorry but the mondeo fans kill the engine driven fan at idle for air flow. The shroud has to be carefully sealed to the radiator to prevent leans and ensure that all air is drawn through the radiator. Had this setup on a fairly stout 308 in a VK and it's never overheated. not even in slow heavy traffic on a 43'c day. Have to run the currect temperature switch to trigger them on and off at the current temperatures. They work fine as long as the rest of your cooling system is up to scratch.

[VK SL 3800]

Ya reckon? the viscous fan on my 308 draws pretty hard and there is a lot of air flow from it, easily enough to cool the engine at idle but saying that i did replace the clutch unit itself cause it was rooted and not locking up enough to drive the fan properly so maybe yours wasnt 100% either? either way heaps of people complain about thermos not cutting it but i have never tried them on a 308.

[torch]

sorry but the mondeo fans kill the engine driven fan at idle for air flow. The shroud has to be carefully sealed to the radiator to prevent leans and ensure that all air is drawn through the radiator. Had this setup on a fairly stout 308 in a VK and it's never overheated. not even in slow heavy traffic on a 43'c day. Have to run the currect temperature switch to trigger them on and off at the current temperatures. They work fine as long as the rest of your cooling system is up to scratch.

Sure you are talking about the 7 bladed clutch/viscous fan with a properly installed shroud? At 800rpm and when they are in the +80C condition(what is needed to activate them fully) they pull just as much air as an au ford twin fan set up. and once the revs increase unlike the elec fans, the flow continues to increase, important in some cars that will become marginal on the highway, or in heavy engine load/low speed use if they dont run the engine fan.

[Lewie]

What about the Series 1 VT V8 thermos? Could this be an alternative? I bought one for my car (yet to be fitted as still has 202) as I was following threads that suggested that these thermos were up to the task.

Any thoughts on that avenue?

[Sabbath']

A member from here has VT thermo's in his VK so they will fit, plus assumably up to the task

[ari666]

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.

[Cane_It]

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 shit 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.

[ari666]

i deserved that lol. look, at the end of the day, my whole post was hypocrytical cos' i have thermos on my VK, i think i was more trying to highlight the fact that its not as easy as "sticking a couple of VT thermos on" there really needs to be a lot of thought going into it and a good understanding of electrical systems. not the type of thing a guy with a pair of side cutters and a carport can get away with.

but yeah agreed, this subject has been done to death. a simple search would have yielded 100 results.

[Cane_It]

It's cool.
if you want to be clever with how the fans come on, you can use a tach relay (commonly used in LPG conversions) to trigger the two fan relays so the fans only run while the engine is running. ie when the coil is emitting a pulse.

Good that you have it sorted, it is involved, but in my opinion worth it if done properly, and I enjoy reading your posts, they're among the more informative on here.

[Gudgeon Pin]

The fan i got is 4 pronged thing think it was 6 banger one, dosen't get that hot on normal days just hot ones. it's not viscous it's constant so follows the revs. bolts up to vn waterpump and clears radiator comfortably. thought of putting in thermo but now that weather dosen't look like summer might not worry.

[torch]

The fan i got is 4 pronged thing think it was 6 banger one, dosen't get that hot on normal days just hot ones. it's not viscous it's constant so follows the revs. bolts up to vn waterpump and clears radiator comfortably. thought of putting in thermo but now that weather dosen't look like summer might not worry.

There is your problem,vn v8 should be at least running the 7 blade fan and viscous thermatic coupling with proper shroud.
You maybe keen to fit eleccy fans because they dont rob hp and give better fuel economy, in normal road use, complete fallacy.

Comparisons have been made with fixed fans robbing 15-25 +hp on the dyno at obscene rpms, but if the comparisons were done where you are driving the car forwards on real roads or with clutch fans at regular operating temp, then there would be no difference, the clutch fan is freewheeling for 99.9% of the time and even when it is thermatically engaged, rarely at highway speeds(it will roar and move a heap of air when you really need it) the clutch wont allow the fan to spin past 3000rpm and wont consume exponentially more power as the engine revs increase.