rodgling
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| posted on 11/3/15 at 09:59 AM |
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ideal fan switch temperature?
My fan is switched by a switch in the top of the radiator. Currently it turns on when the head reaches 101 degrees (normally the engine runs at 85
when moving).
This seems a high-ish temperature to turn on the fan, would I be better using a lower-temperature fan switch, maybe 5 - 10 degrees lower?
Engine is M3 Evo.
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cliftyhanger
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| posted on 11/3/15 at 10:10 AM |
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But what temp does it switch off? usually 5-10 degrees or so lower. So it may only switch off once down to mid/low 90's.
If you want to run cooler, you would probably need to swap the thermostat for a lower temp too. But modern engines seem to like running hot.
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Paul Turner
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| posted on 11/3/15 at 10:25 AM |
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On my Zetec I use the 88 degree stat and a 95 degree fan switch. From memory it switches off at about 91 degrees.
But in truth its only there should I forget to manually switch the fan on.
Think on the Focus the fan switches on at 102 degrees so 95 is well bellow.
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big-vee-twin
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| posted on 11/3/15 at 01:45 PM |
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On my Duratec the stat opens at 85.
My fan switch turns on fan at 95 and off at 85.
Duratec Engine is fitted, MS2 Extra V3 is assembled and tested, engine running, car now built. IVA passed 26/02/2016
http://www.triangleltd.com
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adithorp
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| posted on 11/3/15 at 03:28 PM |
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A lot depends on where the fan switch is. In the rad are usually on around 85-90c ish but if on the engine (stat housing usually) they come on 95-100c
ish. There can be quite a variation though; My R1 is switched at 105c by the ECU, using the temp sender in the block.
If the engine is holding at 85c in use, then your stat temp is fine. As long as the fan is on around 100 (engine temp) then it won't boil as the
pressurised system raises the boiling point. However 5c less on the fan switch might be better just to be on the safe side.
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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rodgling
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| posted on 11/3/15 at 03:45 PM |
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quote:
Originally posted by adithorp
A lot depends on where the fan switch is. In the rad are usually on around 85-90c ish but if on the engine (stat housing usually) they come on 95-100c
ish. There can be quite a variation though; My R1 is switched at 105c by the ECU, using the temp sender in the block.
If the engine is holding at 85c in use, then your stat temp is fine. As long as the fan is on around 100 (engine temp) then it won't boil as the
pressurised system raises the boiling point. However 5c less on the fan switch might be better just to be on the safe side.
Yeah, this is my thinking.
Ideally I suppose I'd have my dash turn the fan on based on both speed and temperature so that it pre-emptively starts the fan when the car is
halted, but for now I'll keep it simple and just swap the switch in the radiator for a slightly lower-temperature one.
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