I have a 71 GS350, engine with auto and air, that runs great. My car has a stock 7 blade fan, factory shroud, and a cheap fan clutch which seems alright. My stock radiator seems perfectly clean (recent thorough flush) and it circulates very well when you visually check it. My car has a new properly operating 160 degree thermostat. I have high quality aftermarket guages which I believe are very accurate. My car runs at 170 degrees or so in town and at about 210 on the highway. After a highway run, it cools off to 170-180 on slower streets. I live in Texas and it's already about 90 here and full sun. Almost too hot to drop the top! Is this normal? I would like to see 160 all the time, wouldn't I? Suggestions? TIA Frank
If it runs hot on the highway and cool at lower speeds, that typically means that the radiator is of insufficient capacity, or is partially clogged. Any BBB deserves a 4 core, as the 3 core is insufficient in many cases. For every .010 overbore, it is possible for the engine to run 10-15* hotter. It is not possible to look into a radiator and know for sure how clear it is. If the radiator has been in the car a long time, I would replace it with a 4 core or 2 core Aluminum. Also in your climate, you could run 100% distilled water with a bottle of Red Line Water Wetter(or equivalent). The more A/F you run, more inefficient the coolant is of transferring heat. IMHO, 170-180* is optimal temperature.
I agree. I've always used the old "if it heats up too fast, it's the thermostat; if it heat's up in town and cools off on the highway, it's the airflow; and if it heats up on the highway it's water flow" rule. I guess I need a new radiator. Thanks, Frank
