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<div style="font-size: 10pt;"><div dir="auto">First , thank everyone for positive input on this.</div><div dir="auto">I am installing the temp. gauge sender in the cylinder head. </div><div dir="auto">Years ago I had a 1940 Chevy coupe street rod. It had a Flexilite brand adjustable temperature sensor to turn on the cooling fan. It's sensor bulb went into a rubber arc'd piece that allowed the sensor to be placed into coolant where a radiator hose slpped onto a hose nipple. I had it located at the thermostat housing. I'm leaning towards something like that. Most modern temperature sensors are designed for 195° as an initial "on" temperature. Also most I could find at the local junk yard are going to be very modern and the bung they screw into would be a plastic radiator. I'm using a stock 1275 cross flow radiator. If I had a decent temp switch ( 180° or lower?) And a copper/ brass bung , I could solder it into the radiator end tank. Or possibly into the lower coolant cross tube . Yes I know the hotter coolant is on top not on the bottom. Possibly on top of the thermostat housing , although the rear of head heater tap is going to be a bypass up to the thermostat housing which may make that casting a bit "busy" for a thermostatic switch mount. Those cast iron cross flow thermostat housings are awfully heavy and rather thin in the domed area over the thermostat. I'd use an alloy one of I had one that pointed the right way.... As of this writing I'm committed to using the cast iron one and brazing a 90° fitting on top for the coolant bypass back to the heater port on the head. I'd love to do it with AN fittings and cool braided hose , considering the "we tight" budget , that's not happening. </div><div dir="auto">My radiator guy is 1.5 hours away and he might have a copper or brass bung ( he must have 500+ junk radiator that he uses for pieces to modify radiators for customers) but too far to drive on a gamble. I could shop old foreign cars in our local pick-N-pull ( our "breakers") and test them for what temperature they make contact to close a circut. Somewhere I remember the old VW's ( rabbit & Scirocco days) had pretty reliable sending units. I need to do some research looking into early electric cooling fan system operating temperatures or pressures ( higher pressure systems traditionally were higher temperature systems from past experiences).</div><div dir="auto">More to come as I get more input.</div><div dir="auto">Chuck</div><div><div dir="auto" style="font-size:9pt;"><i>Sent from my LG Mobile</i></div></div></div>
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