Product Information - Prestige Parts® 78°C Thermostat UE36600-78

We’ve never been particularly happy with the factory Boot/Trunk Lid gas struts, which provide very little assistance. Now we have designed our own version, which combines a self-lifting actuation to the fully open position with a smooth, slow operation. These enable the lid to be fully opened either by operating the button on the lid, or the switch inside the car.

Whichever struts you are fitting, you may find they are tricky to fit, so here are some guidelines to help you.

Prestige Parts® thermostats are manufactured to the highest specifications by a specialist provider of thermostatic units, and only for the Prestige Parts® range. UE36600-78-X is geometrically identical to the OE thermostat and features the same valve in terms of diameter and shape. However, modern production techniques have been used to improve performance from that found in the original design, most particularly by achieving more consistent and reliable performance over the lifetime of the thermostat, as well as by using modern testing equipment to control product quality and consistency. The Prestige Parts® thermostat features the original lead safety plugs, and the thermostatic valve is of brass construction with a steel pin, to overcome the problem of chemical galling of the thermostatic valve exhibited in some early original designs, caused by both components being constructed of the same material.

Thermostatic performance is critical to managing engine temperature. Each Prestige Parts® thermostat is individually tested before being released for sale. Two measures are critical to thermostat performance:

STO (Start Temperature Opening, i.e. the temperature at which the thermostat begins to open)
MS (Minimum Stroke, i.e. the distance the thermostat should open by a certain temperature)

• For UE36600-X the STO is 78°C +/- 3°C
• MS is 8.0 mm minimum at 92°C

Other technical data is as follows:

• When the thermostat has achieved a stroke of 8.0+ mm, coolant flow is 261 litres/minute
• Average decrease in pressure within the system = 7.3 p.s.i. at full opening (as per original equipment, when operating at optimum performance).

The original thermostat design and execution suffered from decline in performance over a relatively small number of cycles, mainly due to the technology available at the time. In practice, this meant that the thermostatic stroke (the amount the thermostat opens) would begin to decline after a few hundred cycles. This is evidenced in the relatively frequent replacement of thermostats in the Rolls-Royce and Bentley service schedules. In order to combat this, an increased stroke was incorporated in the original design as a safety feature. Modern designs incorporate a slightly lower thermostatic stroke, which is compensated for by robust and accurate STO and MS performance over time, and in testing superior to the OE thermostat. This is accomplished through incorporation of superior wax within the valve mechanism, and by improved sealing design around the wax pellet, which promotes greater longevity. In short, reproducing a greater stroke is rendered redundant because the thermostat unit is manufactured using methods that promote the maintenance of optimum stroke throughout the working life of the thermostat.