Thermo's v's Engine driven

[Mytqik]

My engine driven fan clutch has decided to lock solid & not spin freely anymore. You can see were it was "walked" down the shaft , chewing it up and is now no longer servicable.

My problem it that a new fan clutch is $200 (From Rip Every Poor C$%t Off)

Do I

A) Stop being a tight arse & just buy the fan clutch
B) Investigate the possibility of installing thermos with temperature control & manual over ride for water crossing???

If B is the answer what setups have people used in the past??

Are there any dis-advantages of using thermos over engine fans??

Cheers,
Randal.

[Shadow]

get a clutch from the wreckers

should be able to get rthe whole fan assembly for about $50-$100

[dumbdunce]

thermos suck. stick with the engine driven.

[Mytqik]

thermos suck.

Clever pun there

As you are mechanic, I value your opinion. But what exactly is it about Thermos that you don't like??

[dumbdunce]

thermos suck.

Clever pun there

As you are mechanic, I value your opinion. But what exactly is it about Thermos that you don't like??

mekanik? pff I ar a engiear! (I open the bonnet, look inside and say "there's an engin' ere!"

thermos almost never cover the entire radiator surface, ie they only draw air through the part of the radiator that is covered by the fan. it's possible to make a good thermo stup by making custom cowlings but most thermo setups just slap against the radiator. Also, the motor in the centre of most low-profile electric fans presents a significant dead area that almost no air can flow through. You will never get better cooling with electric fans when compared with the factory engine driven system. Electric fans are good for (a) front wheel drives with transverse mounted engines (b) applications where the vehicle will NOT be standing or driving slowly for extended periods eg race cars. Their only real benefit is freeing up high rpm horsepower, but the tradeoff is almost always poorer cooling control.

also, your $200 fan clutch is probably going to end up cheaper. Last time I priced thermos, for a dual setup for a subaru motor, with 2x 14" fans and a thermal switch, it was closer to $300 for the bits, and that was before any fitting was done.

cheers

[sierrajim]

Agreed with the downsides of thermos, however you can generally find a cowling off a vehicle with factory thermos that almost fits your existing radiator.

Takes some time to find the right one but it can be done.

The other thing is with thermos you can have an over ride switch to turn them off for water crossings or bog holes.

The factory fan setup is however more simplistic, no extra power drain on alternator, no switches to stuff up etc etc.

If you look at most cars with thermos they have higher output alternators than those that don't. Now take into account your (if you have them) aftermarket stereo, driving lights, rock lights, winch, brighter headlights etc etc ask yourself if your alternator and battery are up to it.

[80UTE]

thermos suck.

Clever pun there

As you are mechanic, I value your opinion. But what exactly is it about Thermos that you don't like??

mekanik? pff I ar a engiear! (I open the bonnet, look inside and say "there's an engin' ere!"

thermos almost never cover the entire radiator surface, ie they only draw air through the part of the radiator that is covered by the fan. it's possible to make a good thermo stup by making custom cowlings but most thermo setups just slap against the radiator. Also, the motor in the centre of most low-profile electric fans presents a significant dead area that almost no air can flow through. You will never get better cooling with electric fans when compared with the factory engine driven system. Electric fans are good for (a) front wheel drives with transverse mounted engines (b) applications where the vehicle will NOT be standing or driving slowly for extended periods eg race cars. Their only real benefit is freeing up high rpm horsepower, but the tradeoff is almost always poorer cooling control.

also, your $200 fan clutch is probably going to end up cheaper. Last time I priced thermos, for a dual setup for a subaru motor, with 2x 14" fans and a thermal switch, it was closer to $300 for the bits, and that was before any fitting was done.

cheers

I totally agree with Dumbdunce but to add to the case a thermo fan can only draw a fixed volume of air and in most cases driving around town in your passenger car you only need the fan to work when sitting at the lights etc etc, when driving the air coming in the front is generally enough to keep the engine temp under control. BUT in a 4B when wheelin you could be at full power in a low gear on a slippery hill but the thermo only draws a fixed volume of air and is in these situations that they wont give whats needed, on a 4B with a fixed fan the fan noise gets louder than everthing else as its pulling huge amounts of air the keep the temp under control. What new 4B's that a capable of going offroad have thermo fans for cooling and if the latest technology uses the dated but proven engine driven fan it must be the best system.

Wally

[dumbdunce]

...if the latest technology uses the dated but proven engine driven fan it must be the best system.

best or cheapest?

[Rainbow Warrior]

mekanik? pff I ar a engiear! (I open the bonnet, look inside and say "there's an engin' ere!"

thermos almost never cover the entire radiator surface, ie they only draw air through the part of the radiator that is covered by the fan. it's possible to make a good thermo stup by making custom cowlings but most thermo setups just slap against the radiator. Also, the motor in the centre of most low-profile electric fans presents a significant dead area that almost no air can flow through. You will never get better cooling with electric fans when compared with the factory engine driven system. Electric fans are good for (a) front wheel drives with transverse mounted engines (b) applications where the vehicle will NOT be standing or driving slowly for extended periods eg race cars. Their only real benefit is freeing up high rpm horsepower, but the tradeoff is almost always poorer cooling control.

also, your $200 fan clutch is probably going to end up cheaper. Last time I priced thermos, for a dual setup for a subaru motor, with 2x 14" fans and a thermal switch, it was closer to $300 for the bits, and that was before any fitting was done.

cheers

So how is a thermofan without cowling worse than an engine fan without a cowling? Apples to Apples comparisons please.
Dead spot? The centre of my fan motor is smaller in diameter than the factory viscous hub thing.
I have great temperature control, 2 fans, two thermostats, my fans hardly operate in the winter, it's not needed on the freeway, or cold rainy weather, engine warms up better in cold weather, I can tell it's running hard when the second fan comes in.
I get maximum cooling when its warm without having to rev the crap out of it.
I've used this system on 3 vehicles with same results.