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#51 ToRunYa

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Posted 08 March 2006 - 01:09 PM

obviously he is!
oh dear (wipes tears from eyes) anyways...
i have two thermo's on my car one on the front on one side and one on the back on the other side. Any particular reason why i done this set up? because the oil cooler was in the road!
car keeps cool in my usual 43+ degree summer days here
only time it got hot smelling was on a 47 degree day but i figure thats acceptable.

#52 _Herne_

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Posted 08 March 2006 - 01:35 PM

When is the book coming out on thermo fans, sheesh we have seen tons of stuff on this lately, seems to be a hobby horse for some. Just fit the bgucking things and lets not make rocket science out of it, they cant be bad as all/most cars made these days have them.

As for you Torunya you didn't even have the guts to admit you were wrong.... nuff said about you! Dont let the door hit ya where the good lord split ya on the way out!

Cheers
Herne

#53 _Keithy's_UC_

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Posted 08 March 2006 - 02:31 PM

lol, guys guys guys...

I'll sort my side of the debate out and you lads can argue it out between ya!

Davies Craig supplies and reccommends the fittment of the fans the way i have done it! Through the radiator. They have even included a diagram and a 2year replacement warranty on any parts affected by the thermo fans mounting (i.e. radiator). This is to cover their asses in the event one splits a radiator tube! But if you do it the way they state (and be gentle about it), you wont break anything nor will it be irrepairable damage!

And they say the fans can be used upstream or down, but they reccommend upstream (the way i have em)!!

Keith

#54 _Herne_

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Posted 08 March 2006 - 02:40 PM

For what it's worth my fans (which work fine) are fitted front side of the radiator and not where the old fan used to be :)

Make sense?

Cheers
Herne

#55 _Flamenco_

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Posted 08 March 2006 - 03:37 PM

I won't enter the debate on the front vs rear mounting but on the topic of mounting bolts through the radiator my old LJ had a setup that looked pretty safe (used for the transmission cooler). There are fasteners available that are entirely made of plastic (a bit like zip ties) for mounting coolers or fans to the radiator, to describe them:

A straight thin rod of plastic with cones all the way down the rod, a round clip is pushed onto the rod and tightens up when it goes past each of the cones (like the lines on a zip/cable tie).

Might be the best option if space is at a premium.

#56 _Yella SLuR_

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Posted 08 March 2006 - 06:21 PM

^ same things I used, although zip bits are more like a thread than straight lines.

#57 antelopeslr5000

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Posted 09 March 2006 - 04:42 AM

I guess what it boils down to in the end is what best suits your application. Front, rear mounted, one or two fans, who really cares as long as it gets the job done.

I have a 16" Davies Craig thermo fan which makes it impossible for me to mount the fan on the front of the radiator due to the bonnet striker so the fan is mounted in the engine bay. I've had the fan for 14 years now and it's still going strong. I previously had the fan mounted through the radiator as per the instructions however after about 3 years the radiator developed leaks. Maybe I installed it incorrectly but when I had my custom PWR aluminium raditor made (at $850 !) I didn't want to risk it so I had brackets fabricated to mount the fan so nothing goes though the raditor core, just for peace of mind.

#58 _Keithy's_UC_

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Posted 09 March 2006 - 10:07 AM

Well said antelope!

#59 _Yella SLuR_

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Posted 09 March 2006 - 11:34 AM

^^ eggsacery.

#60 gtrboyy

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Posted 09 March 2006 - 01:06 PM

Thermo fan debate,will it ever end lol.

#61 rodomo

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Posted 09 March 2006 - 11:00 PM

Z Z Z Z Z Z Z Z Z Z Z Z :ZZZ:

RACV MAN

#62 _Keithy's_UC_

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Posted 27 April 2006 - 04:26 AM

Quick update: Still no leaks in the radiator...

Keith

#63 _PAL066_

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Posted 19 May 2006 - 05:00 PM

Has anyone used one of the adjustable temp switches from JAYCAR electronics
there are two to choose from one at about $80 and the other $30 the cat. no. for the 30 dollar one is KC5381

#64 _devilsadvocate_

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Posted 19 May 2006 - 07:48 PM

Had a look at the jcar site
Things to consider:
Neither look like the are set up to work off your existing temperature sensor, there are others around that can work of this.

Looks like the sensors is thermistor for the cheaper one, which really arent very durable for putting in a moving water flow. How you'd do that is another problem, perhaps putting into radiator hose like the Cdavies capillary switches.....but that's what you want to get away from? Could be taped very hard to the top of the thermostat cover, but not sure how consistent the readings would be.

The more expensive one, quotes temps up to 1200C, which suggests it works with a thermocouple. These are very durable, and not really too much trouble to put inside a rad hose and not cause any troublesome leaks like the capillary tubes.
Ive got one still in the bottom hose on one of my cars.

Trigger on and trigger off temperature, how repeatable are they? and what is the difference between on and off. Suggest that 5C max between on and off is what you want to see otherwise the fans will stay on far too much of the time in warm conditions.
Are the devices suitable for tripping 12V car relays, sometimes the very small current draw of a relay causes problems with some designs especially in switching a relay off.
I couldnt see any info about this on the site so you would need to find this out. The other point is you have to assemble these yourself, do you have experience in constructing small electronic projects?

Edited by devilsadvocate, 19 May 2006 - 07:54 PM.


#65 rodomo

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Posted 19 May 2006 - 11:25 PM

My plan with the LJ (if I ever get to it) and the old Rangie (which will get a new heart over the next 2yrs) is to run thermo's on both and switching them with a Magna fan switch which fits into the lower section of the rad tank and therefore would be a low temp switch. This makes the most sense to me as the lower rad tank you would assume would always have "some" water in it in the case of a leak. My experience with other makes relies on the engine having a reasonably high level of water and if not the fans don't cut in and next thing is a total meltdown. I have also used the craig davies capilary type switch and found it tempermental and constantly in need of fine tuning.

#66 _devilsadvocate_

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Posted 20 May 2006 - 12:13 AM

Yes, also agree with the folly of having the switch in the top of the radiator. They also trigger unnecessarily after shutdown when heatsoaked coolant makes its way into the top tank of the rad.
The switch in the bottom of the rad does create its own problems though. Designing the correct trigger temp is tricky as it depends on the coolant flow rate and the size of the engine above it, whereas this is not a concern when a sensor is placed at the exit, as it is responding to the maximum temp of the coolant.

#67 _Yella SLuR_

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Posted 20 May 2006 - 01:26 AM

Just an update on the thermo installation. ^ only a problem when you have the thermo switch/relay hooked up to constant power supply, i.e. alternator/battery. I'm running the switch to the relay on an ignition circuit now, works fantastic, and isn't killing the battery anymore from the heatsoak issue.

I just love it when things work.

Edited by Yella SLuR, 20 May 2006 - 01:26 AM.


#68 _devilsadvocate_

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Posted 20 May 2006 - 07:59 AM

Just an update on the thermo installation.� ^ only a problem when you have the thermo switch/relay hooked up to constant power supply, i.e. alternator/battery.� I'm running the switch to the relay on an ignition circuit now, works fantastic, and isn't killing the battery anymore from the heatsoak issue.

It is still a problem if the fans are wired only to come on with the ignition.If the car is stopped for anywhere from 2 to 10mins the top tank of the rad will get and stay hot enough to trigger the switch and the fans will come on. Restarting the engine within this time frame will see ~ 20-30 secs until the switch is cooled down. While it doesnt sound much,I find the effect annoying and wasteful of energy and causing unnecessary wear and tear. The effect can be minimised to some extent by using a very high temp switch (>105C), but thats not how Id want the setup on my car. Other than the switch being controlled by the temp of the metal in the cylinder head itself, putting the switch in the bottom of the rad is the only real solution to this prob.

As Yella points out wiring the fans up live(not recommended by me) would run the fans for up to 15mins after switching the motor off, which wouldnt be brilliant for the battery, along with undesirable effect of the fans starting up without warning when you are poking around under the bonnet with everything supposedly switched off. I actually have mine connected to the distributor pulse sensor so that they will only ever come on if the engine is actually running and also bypassed when the starting circuit is activated.

Edited by devilsadvocate, 20 May 2006 - 08:10 AM.


#69 _Yella SLuR_

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Posted 20 May 2006 - 05:36 PM

Also of little benefit once the motor is switched off as there is no water flow. All it does it just makes a whole heap of cold water in the radiator that doesn't go anywhere till you next start the motor.

#70 _Oldn64_

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Posted 22 May 2006 - 11:59 PM

Also of little benefit once the motor is switched off as there is no water flow. All it does it just makes a whole heap of cold water in the radiator that doesn't go anywhere till you next start the motor.

Unless you have an electric water pump as well.... :)

cheers

#71 _devilsadvocate_

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Posted 23 May 2006 - 12:07 AM

Also of little benefit once the motor is switched off as there is no water flow.  All it does it just makes a whole heap of cold water in the radiator that doesn't go anywhere till you next start the motor.

Unless you have an electric water pump as well.... :)

cheers

and also some reason to be trying to cool it down quickly........overheated motor

#72 _Oldn64_

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Posted 23 May 2006 - 12:17 AM

and also some reason to be trying to cool it down quickly........overheated motor

Or maybe your crank is driving something more important????

Cheers

#73 makka

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Posted 23 May 2006 - 12:32 PM

I have just got a tridon thermo switch in the front of my intake manifold.
its neat and tidy and doesnt leak.

#74 rodomo

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Posted 23 May 2006 - 08:26 PM

Also of little benefit once the motor is switched off as there is no water flow. All it does it just makes a whole heap of cold water in the radiator that doesn't go anywhere till you next start the motor.

The water will circulate with the motor off, this is called thermo-syphoning. Works on the heat rises theory. Morris Minor side valve engines had no water pump and relied on thermo-syphoning for circulation. Just a bit of trivia :rolleyes:

#75 _devilsadvocate_

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Posted 23 May 2006 - 09:18 PM

Rodomo is right ^, its also the thermo syphon effect that causes hot water to migrate into the top tank when the motor is switched off......so yes there is circulation even without any fan cooling of the rad.....just enough to be of nuisance value.
Those older systems only worked if the rad was particularly tall, hence the tall bonnet/nose look of the vintage cars.




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