V8 Column for November 2005
 This month we have an extract from one of the V8NOTES recently released in a batch of new notes. As this one is important it is included in this month's V8 Column. It is an example of the good quality of postings on the V8 Bulletin Board which are providing a rich source of material for the long running V8NOTES series. Next month we have a four page V8 Newsletter which will be packed with news of the successful V8 Essex Tour, 2004 an announcement of the V8 Lincolnshire Tour 2005 being arranged by Mike Taylor and more useful workshop notes.


Flamenco Red 2903, the last V8, has recently resurfaced after being sold off from the Heritage Collection at Gaydon. (Photo: Fred Jenns)

Thermostat wrinkle explained
Philip James (Sandglow2868) from Surrey posted a reply to a query on the V8BB which is a useful reference to avoid frustration later. (V8NOTE334 released Aug 05)
Severe overheating difficulties can arise from a simple to cure oversight relating to the thermostat. The V8 engine is prone to air locks in its cooling system and one area where the air collects is in the thermostat housing, the highest point of the inlet manifold. The initial symptoms of this are very high temperature readings during warm up but once the thermostat has opened the temperature the coolant from heating the whole of the thermostat. Temperatures can rise to boiling point before the thermostat opens. Over time the

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thermostat can become distorted and stick, causing erratic temperature variations at all times and further overheating. mounting of the thermostat which can allow air to be trapped and
Figure 3: Thermostat showing the vent and the misleading TOP marking. Figure 4: Plastic float attached to the vent. (Photos: Philip James)

the coolant from heating the whole of the thermostat. Temperatures can rise to boiling point before the thermostat opens. Over time the thermostat can become distorted and stick, causing erratic temperature variations at all times and further overheating. mounting of the thermostat which can allow air to be trapped and settles back to normal. The cause of this is the unusual vertical prevent. Damage can extend to cylinder head gasket failure and water pump bearings.

To prevent this, it is essential that the thermostat is one that has a vent incorporated in it and that the vent is mounted at the top or 12'o'clock position to allow any air build up to be purged away to the radiator. Note that there are two types of thermostat manufactured, one with the vent and one without and both appear to be sold as GTS104 (the recommended 82°C thermostat). For the V8 application, the correct type is available from Land Rover main dealers (part number 602687) or MGV8 specialists (GTS104), but check you have the right unit if supplied from other sources. The non vented unit is cheaper to make and I guess that is why some outlets supply this.