nualln

How high does the coolant temperature level get before engine damage occurs?

Scott H.

That's an excellent question.
There are so many variables that it could be as low as 212*F or as high as 260*F plus

In our vintage you can expect accelerated wear when we get above about 230*F with a good cooling system and a freshly flushed block. Realistically we would like to keep our engines to less than 200*F at the temp sensor. Between 180*F and 190*F would be ideal.

The issue is that what we see is not necessarily the highest coolant temp in the block. Things like Porosity in the casting, hot spots, rough casting flash, the center two cylinders being simeesed (sp?). If someone punched in the old freeze plugs and left them in the block. Etcetera, ectcetera, ad-naseum.

Take your Mustang and Glen's Mustang, for instance, side by side and if both were running the same temp (say 240*F) one of you may see little effect while the other engine seizes a piston.

Where is your's running with the A/C on in this heat?

My 6 cylinder will run a steady 205*F to 210*F in stop and go, when the ambient temp is aver 100*F and I've got the A/C cranked. I keep a close eye on the engine oil, and try not to do a lot of short trips, as Heat Sink can be a big issue in our cast iron engines. I've taken my heat gun and checked out the entire engine, and radiator, everything is very even, telling me I've got a good clean cooling system, so I don't get excited.

Now if it was a 331 with AFR's I would not settle for over 200*F no matter how hot the ambient temp, or if I was sitting in the line at Burger King for 3 hours with the A/C full blast. That is an easily attainable goal.

HTH,

Soaring

Ask a simple question, and get a complicated answer from Scott. Boiling temp varies in different altitudes. Boiling temp is the highest temp you want to reach at sustained driving conditions before damage occurs. Down here in Texas that is about 212 degrees Fareinheit. If your engine is constantly boiling and running out of the rad with a 13 pound cap, then you need to take measures to reduce your running temp.

Scott H.

Good one Glen!!![sm=exactly.gif]

nualln

Well, when I'm coming home from work at 4:00pm, the A/C is on full blast, its 103, and there are about a dozen traffic lights in a 10 mile stretch, it can get as high as 220F.
When I look under the hood, I dont see any coolant coming out of the tube. I can lift up on the red lever on the cap and I see spray coming out of the tube, but thats it, no dripping coolant. It's not the gauge, cause the previous owner had a cheapo one in there, and my new autometer reads the same thing.

Will an electric fan solve this problem?

68COOP

YES! I have an elec fan, and when I turn it on, I can watch the guage drop. Not only that, it frees up some ponies, not having to pull the fan off the motor. I just went with a 3 row rad, and aluminum pump, and my car never gets above 190 on the guage, as long as I turn the fan on at around that temp. I have it wired in with a toggle switch, but they have kinds that will kick on at a certain temp too. Auto Zone has them, as do other parts stores I'm sure.