Thermostats how and why.

[tbro]

Shamelessly pinched from Tridon site,


Selecting The Correct Thermostat
The best way to ensure that no problem occurs when fitting a new
thermostat is to make sure that the new thermostat is the same
style as the one being replaced. The following should always be
checked prior to installing a new thermostat.
1 ) Thermostat style (Non-bypass or Bypass).
2) Thermostat dimensions.
3) Correct operating temperature.
All thermostats in this catalogue are correct for the vehicle
applications listed in relation to operating temperature, thermostat
style and thermostat dimensions. Please use the vehicle
application guide in this catalogue to determine the correct
thermostat for your vehicle.
Why high-flow thermostats increase your
vehicles cooling system performance.
Todays engines tend to generate more heat than older vehicles. Most
vehicle engines are controlled by computers and sensors to specific
temperature ranges which makes fitting the correct temperature thermostat
even more important.
In the past if an engine had an overheating problem people tended to use a
cooler temperature thermostat to overcome this problem. This cannot be
done with the high-tech engines of today especially with vehicles that have
thermo fan switches fitted. These switches along with other sensors are
programmed to come on and off at specific temperatures set by the vehicle
manufacturers. Changing to cooler temperature thermostats could lead to
switches and sensors working differently to the settings as specified by the
vehicles manufacturer and in turn could lead to overheating and subsequent
engine damage. Vehicles with extra loads especially if towing can also
generate extra heat through the engine. The need to have cooling systems
working more efficiently becomes even more important for vehicles with
extra loads.
Tridon Australia now offers a High-Flow Thermostat to improve cooling
system performance. High-flow thermostats have a larger valve (Fig.l) and
allow approximately 30% more coolant to flow to the radiator than standard
type Thermostats. Using High Flow Thermostats eliminates any need for
using cooler temperature Thermostats as a temporary cure for overheating
problems as was done in the past. Using correct High Flow Thermostat at
correct temperatures specified by OEM manufacturers will not interfere with
the engine management system.
All High-Flow Thermostats are fitted with a jiggle pin that enables the system
pressure to be stabilised so that the valve opens easier. The jiggle pin also
allows air pockets to move past the Thermostat and the temperature to be
regulated more efficiently. Fitting High-Flow Thermostats will allow your
vehicle cooling system to operate more efficiently.



Thermostat Testing Procedures
- Correct Field Procedure
The thermostat may be tested in any commercial type of tester for
checking the thermostat operation. For accurate and valid results, the
tests should be pedormed under carefully controlled conditions as follows:
1. Fill test container with 50% water 50% coolant concentrate.
(minimum 2 litres)
2. Manually open the thermostat sufficiently to insert a fine thread under
the valve seat.
3. Suspend thermostat by the thread in the container. The thermostat
must be fully submerged and not touch the bottom or sides of the
container.
4. Heat the liquid slowly to activate the power element properly. Agitation
of the test fluid is required for accurate results.
5. Place a thermometer into the coolant so that the bulb is adjacent to the
thermostat temperature sensing pill.
6. Observe the thermometer and note the temperature at once when the
thermostat drops from the thread. This reading is the approximate start to
open temperature of the thermostat.
7. The thermostat should be replaced if it opens at a temperature more
than 6øC (1 IøF) below or 3øC (5øF) above the specified opening
temperature. The temperature should be increased and the thermostat
observed to make sure it fully opens. The thermostat should be fully open
at a coolant temperature approximately 12øC (22øF) above the specified
opening temperature.
8. When cool carefully examine the thermostat valve to make certain it is
properly seated. If it does not seat properly, it should be replaced. It is
important the replacement thermostat be of similar design with the proper
start to open temperature specifications.


© Tridon Australia Pty Ltd (1998) Master Catalogue:Thermostats, Radiator Caps, Thermo Fan Switches & Gaskets, 4th Ed., mail@tridon.com.au

[wun911]

I think the pointy bit faces out and the little hole with the jiggle pin goes on top.

It fits both ways and in any orientation, and if you put it in backwards and upside down you tend to overheat and stuff.