Otter switch

[DTV]

Can anybody tell me where to get a 74c fan switch for TVR S3 please

[magpies]

That temperature is very low - lower than the thermostat probably?

The thermostat is designed to keep the engine temperature at its opening point or higher.

The fan is operated by the otter switch and that should be at a temperature approx. 10degC higher than the thermostat.

So for example a car with a thermostat opening temperature at say 82degC would probably have an otter switch operating at 92degC and switching off in the mid 80's. Engines run more efficiently at higher temperatures rather than lower.

[Penelope Stopit]

I think 85 to 90 is good but.......

[phillpot]

Around 90 degrees is normal but if you really want to go much lower try one of these.

[DTV]

Thank you that’s all very informative SC Parts do an 88 to 96 Does anyone know what the otter switch comes from Steve Heath seemed to indicate Landrover

[phillpot]

What type do you have?

Original is a clamp on type but if stainless pipes have been fitted you'll probably need a threaded one.


Why 74 degrees ?

[Alan461]

Fitted a Kenlowe variable (fan)stat like Mike mentioned above.
I put the sensor on the output from the radiator rather than the output from the engine.
Engine temperature stays level when parked because it receives cooling from the rad with the fan running, rather than start to overheat before fan operates.
I can’t understand why they put the otter switch downstream of the stat.
Maybe someone could explain. TVR right?

[DTV]

Mine is the screw in type. In Steve Heath book he recommends a switch with a lower value ( 74c ) from Tower View Race Services who no longer exists
The switch should operate at around 90 c

[phillpot]

DTV said:

In Steve Heath book he recommends a switch with a lower value ( 74c ) from Tower View Race Services who no longer exists

total nonense.


And I'd guess "everyone" else is running quite happily without one

Edited by phillpot on Saturday 8th June 09:08