So I just found time to test the temp gauge problem I was having and I want to verify my results. I got a digital probe thermometer and put it in the opening on the top of the radiator, and it registers a steady 175 degrees. The digital thermometer I used has shown accurate temps before, is this an accurate measurement of the water temp that the sensor in the engine would read? I ask because I am guessing the sensor in the engine would read higher but I am definitely no mechanic! I am just getting this truck back on the road and I want to make sure I don't damage the engine. And I do not know much about engines so I want to make sure I am getting the right info.
I Would have to say No , The Liquid where the temp sender would be higher then in the Radiator as Its allready been Recirculated & cooled to a certain extent . How many degrees diference, I have No clue . I Keep a Stewart Warner Manuel Temp Guage , That I Know is accurate With Several different fittings to adapt to about Anything, To Check against the Actual Guages readings . Just My Opinion though. Best of luck. Bob
Temperature Readings Yes , it's prolly accurate ~ the dashboard's gauge sender bulb is fitted to the back of the head as that's the hottest place in the engine so you get plenty of warning before it overheats . These engines were built to run fairly cool . The stock coling system is sufficient to keep a 500 C.I. Caddy engine running cool in Death Valley so your little old InLine 6 Banger should never overheat if it's properly tuned and you system is clean of scale . I run a 185° thermostat in my '49 as the engine is more efficient and lasts longer , more power , better fuel economy etc. , etc. - hoever this means it's much closer to the boiling point on thos hot days when I get trapped in blistering hot city traffic . The temp in the radiator neck is usually 15 ~ 20° cooler than in the back of the block so your 175° F reading is dead nuts where it should be .
