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you know, i'm looking at these pictures now & something concerns me. when i spoke earlier about coolant flow bing from the engine to the radiator over the thermostat, it was a general comment; cars are engineered that way for a reason. FYI, a centrifugal pump like the boxster's water pump is designed to suck from the center and blow to the edge, so we can deduce direction this way.
looking at our photos, two things strike me as very odd:
1. the thermostat opens to the low pressure side of the water pump. this means that the pump IS sucking water from radiators across the thermostat. this is not common, and strikes me as incredibly stupid. the cooler water from the radiators would cause the thermostat to start to close again almost immediately. the temp the thermostat is 'seeing' is the cooler radiator water combined with some engine recirculated water. this would imply our 190deg thermostat is actually running the engine at MUCH higher temperatures.....by design. essentially, the thermostat would try to achieve a 190deg exit temp from the radiators. hmm.....
2. the second thing is that our thermostat looks like it may be two thermostats in one. it looks like the bottom of the thermostat covers 'D' in the photo & like a second spring/actuator rod opens this second 'stopper'. my GUESS is that this is an attempt to heat up the heater core / passenger cabin before any other concern. i want to drop one into a water bath to see if this is the case.....
raby's point w/ the low temp thermostat is that when they measure engine temp at multiple points on test motors, they see some areas that get really hot WAY before the OEM thermostat starts to open. this design could be a reason why.
anyone else have thoughts on this?
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