Another way to check temperature at the radiator is to use an old fashioned thermometer (meat or one from the parts store().  Warm the engine up to where the gauge usually shows (don't put the cap on) and stick the thermometer in the water


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

If your engine was really "HOT" it would be boiling over - not just a little overflow - a lot. The gauges can be "re-tuned' to read a bit more accurately - but making a check with a real thermometer - infrared works best - to settle your digestion.....is a good idea. Overflow space is exactly as DLR described above - leaving room in the upper tank of the radiator.

I'll try to hunt it down - but I used to have a photo of the opening on the back of the temp gauge where the needle position may be adjusted. The opening shows the edge of a cogged wheel where a small screwdriver can engage a tooth at a time. We had an ancient "wind-up" alarm clock that adjusted speed the same way, if you've seen one. 

 
 Steve Metzger       Tucson, Arizona

I agree totally with miker. I have a meter like that from Harbor Freight and would never travel with out it. Great to check tire temps too. I do not have a recovery system on my 56-292 and always leave the coolant level down 1" . I learned the hard way with that, it was always pucking out a small amount of coolant if I didn't. I use a #7 cap.
On your short trips does the temp gauge slow come down on a down hill run. If it does your probably ok. Good Luck.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

I don't remember your previous post, but just a couple,comments.

The factory gauges are notoriously inaccurate.

The oil breather will show vapor after a long drive, with the oil warmed up. That's why I prefer a PCV system over a road draft tube, and a closed PCV over an open one.

If you shut the engine off hot, it will heat soak and gain temperature at the top of the thermostat housing and the radiator. That can be the gurgle you hear. If you don't have a catch can and a sealed radiator cap, you'll end up with air space at the top of the radiator. If you fill it, it just repeats the process. Keeping air out of the system, using coolant recovery, is what most modern cars do. But they're designed to run over 200 degrees or so.

Go buy a cheap infrared thermometer. Check the temp at the top of the radiator and the themostat housing. Then, you'll know where the engine is running temp wise. You can check the bottom of the radiator too, and see the temperature drop. It's hard to believe, but I've seen several of these cheap ones run within 1/2 degree of a really expensive Fluke meter. Typical one from Amazon.

http://www.amazon.com/Etekcity-Lasergrip-1080-Non-contact-Thermometer/dp/B00DMI632G/ref=sr_1_4?ie=UTF8&qid=1463631184&sr=8-4&keywords=infrared+thermometer

You're probably just fine if your running a 50/50 mix of antifreeze and a 10lb cap or so.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Hey guys


I've posted topics about this before, but I've got some more concrete information now that my car is running well enough to drive long distance. It's about the temperature the engine seems to hover at.

After about half and hour of 50ish mph driving on country roads, the temperature gauge reads just about at the far end of the solid white line, hovering a little higher little lower from then on out.


Now I'm not expert on classic engines so the condition of the engine after stopping again when reaching this temperature I'm not sure if they're normal or not. After reaching our stop I lifted the hood to let it cool down a little, there was white/grey some coming from the oil breather, a dribble of coolant coming from the radiator overflow tube, and the inside of the radiator was making a gurgling sound every say.. 2 seconds.