This is a good spirited debate…
My comments about thermal damage to the engine are based upon the Wed Jul 22, 2009 11:00 am, post to ground the heater element wire and thereby energize the heater element permanently; from what I am reading the intent being to open the thermostat further or fully (most likely further) to achieve an 85 degree running temp. With all due respect, I stand by my original posting that this will allow some level of thermal shocking of, particularly, the engine block and is akin to a failed (open) thermostat that is not reacting and sensing the actual coolant temp.
Artificially creating the illusion of a hotter engine (ground the wire) is not shifting the effective range of the thermostats sensitivity but instead narrowing its sensitivity, if, it is sensing high coolant temperatures all the time… or sensing a higher temperature (margin) than that which actually exists. The thermal shocking will occur during periods of low-load when, for example, the vehicle is coasting down a grade when the thermostat would normally close or move toward closure. Instead, if I am understanding the operation of this thermostat correctly and applying this plan as described, the thermostat will remain open or more open than it should during this period of increased cooling which will result in a thermal change to the block… a shock. Steel, cast-iron, even aluminum does not like to willingly change shape and size without complaint, particularly when these castings have varying thicknesses and distances from the source of heating and cooling. One of the principal purposes of the thermostat is to try to keep the engine the same size during all loading situations.
High engine temps also contribute to high(er) combustion temps and the reduction of Oxides of Nitrogen and hydrocarbons. Lowering engine temp can lead to plug fouling, misfire, and all of the things that Rover owners, or any owners, dislike when dash lights turn on and ECU’s (or OBD) start to complain.
At the end of the day, I understand perfectly how the original poster feels about having an engine running that hot and under that much pressure… 22 PSI is a lot, and so is the temp. I suppose that the engineers who designed this heated thermostat were doing their best to have a hot engine run hot, and when it tried to get hotter, gave it an escape route by making the thermostat suddenly think it was getting even hotter and thereby provided (additional?) cooling.
For all of the technical reasons for high temp and high pressure, the danger is in a ruptured hose (as the original poster mentions) or blown-out “freeze-plug”. 105C = 221F, 10 degrees above boiling, so steam comes out. 22 PSI increases the boiling point by 66F, so we are now potentially talking 287F for a fully stuck closed thermostat, and hose that ruptures as a result of max pressure and temp, that is high-pressure, deadly temp steam. Drive it up a mountain to a lower atmospheric pressure and things get even hotter (lower boiling point) and higher pressure in the event of a rupture (extraordinarily vigorous discharge)… Maybe this engine is really a steam engine in disguise?
… And then of course there is the whole discussion about heating element longevity when the heating element is permanently heating, when it may have been designed to be intermittently activated…
All the best.