Observations after the new pump and thermostat.
The obvious change is the engine is definetely running cooler on a typical run, the indication is it is running around one needle width cooler, my favourite test climb is a 550 metre hill leading away from the coast, this would bring the gauge on a typical day at least to halfway, on a very hot day about two needle widths below the red, now it climbs about one needle width, assuming I can extrapolate from that I will assume that halfway or a little more on a hot day?
Now here is the interesting bit, after reaching the top of the hill and starting down the other side with a trailing throttle the gauge would come down as expected, but would continue to drop right down below the previous normal running temperature. Only after the car had been driven on the level for a couple of miles would the temperature come back to the 'pre climb' temp.
I have observed this with previous vehicles so thought nothing of it until I had a think about it, on a typical engine the now very cool water from the rad is entering the engine from the bottom hose and will course through the engine cooling it as it goes until it reaches the thermostat at the TOP of the engine,the cold water would bring down the temp as expected, the thermostat holding that water in the block until it reach the rated stat opening temp.
Now on the 80 the stat is in the bottom hose reading the incoming water and would react to the cold water quicker than the top position thermostat, so the reason my engine temp dropping so severely after the climb was because the thermostat was sticking wide open after the climb.
With the new thermostat the temp drops down to normal and holds it there even during the run down the other side of the hill, I have seen dozens of thermostats stick closed and just as many stick open but never one that continued to operate just very very slowly. Of course none of this would have been noticed without the temp gauge mod which IMO is one of the most important mods you can do on your 80.
As an asides, today so I could measure the radiator for the planned electric fans, I removed the fan/radiator shroud, (I have somehow misplaced the old rad I took off?) and then I got a call from a friend to go to his house and check out why his burglar alarm was sounding, (it seems he got an automated call while he was in another province miles away) you guessed it, the house is on the other side of the 550 metre climb, so up and over I went and noticed the temp did not alter from the previous readings taken earlier when the shroud was fitted, a clear indication that the cooling system on the 80 is designed with plenty of spare capacity built in, what a machine, the phrase 'they don't make em like they used too' must have been coined for the 80!
regards
Dave
PS, in case you were wondering the house alarm was a false one triggered by a window not being closed properly.
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