Thermo fan switch

[gary70au]

Hi guys,

I am thinking of using a tridon thermo fan switch to control my fan.

Can anyone suggest a temp range i should get for a 347 with alloy heads?

I am assuming if they say the range is 82 to 87 degrees, the switch activates somewhere between those 2 temps and stays on, until the temperature drops below them again. Does this sound right?

Tridon fan switches

Cheers

Gary

[hybrid]

I would guess it would come on at 87 and switch off at 82.

That should be ok I would have thought. You can probably do a search for windsor optimal operating temp.

[hybrid]

180F is around 82C, so that stat is probably about right for what you want.

[gary70au]

Thanks Hybrid, i just came to those figures myself. Thanks for confirming them.

Should i get a thermostat for that temp as well?

[hybrid]

Yeah your thermostat should definitely be aiming to be open somewhere around that time (82C), otherwise your fan and thermostat will not be working together.

Obviously you want your thermostat to be fully open before the fan comes on. Ideally you want the thermostat and radiator cooling the engine (especially when moving), and the fans only turn on when they are required.

[gary70au]

Is there any benefit to wiring the fans so they can stay on after the ignition is off?

I know newer cars do it, i just can't see it being effective without the waterpump spinning. Or does the water still circulate due to temperature variance?

[hybrid]

Theoretically, thermal flows should mean that the hotter water will want to move to the top of the engine, so there should be some sort of flow after the engine stops.
Not sure how much though.

Personally I wouldn't risk the flat battery. Thermo fans draw a lot of current.

[gary70au]

The current draw is one concern, however i am a bit worried about heat soak damaging the new heads.

In the past a short while after stopping the temp is showing at the top of the gauge.

[hybrid]

I guess that's for you to decide then.
There are plenty of cars with alloy heads that don't leave the fans running after the car is switched off.
You could also just have one of two fans running on rather than both.

[gary70au]

Not sure what to do.

It had a factory 86 mustang clutch fan on it when i got it, kept it at a happy temp. Some of the blades were cracking though, so i put a single thermo on.

Seemed to keep it under control but would have been iffy in heavy traffic.

I have replaced the front inner engine bay panels and rad support as the originals were pretty bent up.

I now have a new set of blades for the clutch fan but it doesn't fit in anymore. It seems the front end being out of whack allowed a bit more fan to radiator clearance.

I think it may be an 86 radiator as well.

[hybrid]

Do you have a shroud on it?

[donoauto]

i just fitted a 82c thermostat & used a triden TFS200 or TFS220 - can't remember part# until I get to work but the switch turns on @92c & off @ 87c. Tried a 95c-90c - TOO HOT & tried a 85c-80c(I think.......or was it 90c-85c????) either way - TOO COLD. The cold 1 wasn't in snyc. with thermostat & fan stayed all the time when engine was hot.
NOTE: I'm NOT running alloy heads yet!!! The triden part #'s of the other 2 switches was ( & again , don't quote me on these part#'s til I get to work ) TFS110 & TFS100. All have a 3/8 gas thread which I screwed into my inlet manifold ( I haven't got a heater so I used 1 of the heater hose locations)

[gary70au]

Hybrid, there was no shroud fitted when i got it.
Still not fitted as the fan won't even fit anymore. I have a 14inch (i think)thermo fan on it now.

Mark, thanks for the info. Looking at the tridon site it looks like you have the TFS200.

What radiator and fan setup do you have in yours Mark?

[donoauto]

16" thermo , no shroud , stock radiator I think but really don't know....

[donoauto]

& here's where the switch is ( just left of the dizzy in inlet manifold)