Countach cooling questions

Hey all, I’m a relatively new owner of an ‘85 downdraft Countach. I took it for a drive the other day and had some cooling system issues, and now I have a few really basic questions.

Background: it was about 70F out and I was doing a twisty mountain drive at low speeds, 20-30mph. Temp reading on the dash was maybe 90-100C. I stopped and stepped out for a photo, letting the engine idle since it can be finicky to start when hot. Of course someone had to stop and talk to me about the car and within about 2 minutes I saw coolant dripping from the engine bay. I shut it off and let the engine cool. No coolant leaks visible on brief inspection, definitely not from the reservoir tank in the upper left corner of the bay, but I did hear trickling around the back of the engine for a bit. It soon stopped dripping, and since the car only lost maybe a half quart of coolant overall, after about 30m with the engine cover open I started it back up and drove back to the garage, watching temps carefully, and stopping once to check for additional drippage. On the way back, temps were around 60C at highway speed, but when I got to town and stop lights temps got up probably above 100C – basically to the line on the gauge just below the red line.

Questions:

• Where is the cooling system supposed to let off extra pressure? The cap on the reservoir tank doesn’t appear to have an overpressure valve.
• Any specific areas to look for coolant overpressure leaks?
• What are normal and dangerous temps for this engine?
• Should the car be able to keep itself cool at idle?
• Any recommended cooling upgrades, e.g. upgraded electric fans?

Thanks a bunch all,
eric

 

Thanks! Forgive the noob questions, I’m still trying to understand how this car works.

Does it actually have an expansion tank? There’s a reservoir tank but as far as I can tell no pressure valve for expansion into it. Based on the diagrams it looks like the tank is just pressurized along with the rest of the system. It’s not clear to me where overpressure is supposed to be released. In any case, the coolant didn’t seem to spill from the cap of the tank, the tank was dry.

One other clue, I didn’t see any steam from the engine bay at any point, so I don’t think it spilled on the tank and evaporated, but I could be wrong.