A couple things to keep in mind. With the Permacool, there are two chambers with two holes each, one is marked “cold” and the other “hot”. The waxstat resides inside the “hot” chamber and is normally collapsed, allowing oil to flow from the “hot” side to the “cold” side until it heats up. When the waxstat is heated, it expands to block off the “cold” side (forcing all the oil to go through the cooler). You need to look at an installation diagram and think about this – or just hold a Permacool in your hands and look inside, then toss it into boiling water and see what happens. All their percentages are just estimates and based on the path of least resistance being the more direct path from tank to oil pump (bypassing the cooler). I don’t think the actual percent number means much. But I do hope and think that the idea of limping home if it fails might work.
PermaCool works differently than the automotive video above (thanks Mike). We rely on the expansion of the waxstat, which I do not know if it is fail safe to both force oil through the cooler and to keep it flowing there (purely by action inside the waxstat bulb). If the waxstat fails to expand, it allows maximum flow between “hot” and “cold” chambers (oil bypassing the cooler as resistance allows). When fully hot, it blocks off the “cold” side, whereas in automotive use, it opens to the radiator.
However, in automotive use, the MotoRad is fail safe because of the spring clips on the side of the spring in the housing (see the video). In our PermaCool application, the MotoRad housing, spring, and clips are cut away and not present. Here is a picture (if my attachment makes it) of the stock waxstat removed from my PermaCool (on the right) and the replacement 195 degree MotoRad P7200-195 on the left (cut out of its housing). Note, even though PermaCool says their ‘system’ is 180 degree, to achieve this they use a 170 degree waxstat. So, I am thinking that using a 195 is a 25 degree F difference (from the 180 degree PermaCool ‘system’ to a 205).
And, as I pointed out earlier, when I tossed both of these waxstats into boiling water, only the new one actuated by expanding. The stock one just sat there. I assume it has failed and done so in the closed position, meaning that inside the PermaCool it would always allow oil to pass between the “hot” and “cold” chambers in maximum heat-up-the-oil mode. If this happened inside a car, I don't see how it would make the fail safe clips work, unless it first expanded too much before failing to expand at all. Perhaps it failed after I removed it, as I never saw high enough oil temps despite this. So I assume this is what happened. But I admit to being unsure.
Dennis
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