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Eric m":33uc9vzx said:
Rebuilt 200 slightly raised compression and comp 252 cam. Timing at 12 deg. Advance works. New radiator, water pump, hoses and classic auto air ac system which includes a new heater core. Runs terrific. Three row autozone radiator six blade fan and fan shroud. If I let it idle in my driveway in gear with ac on on a 70 degree day, my infrared gun reached 213 on the sending unit and 206 on the upper radiator tank. Upper hose is hotter than lower hose. I can't believe an electric fan is the only answer. 180 thermostat.
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Okay, few simple things.

Your car might not be over heating, but if your not comfortable with it feeling that hot based on your 27 years with it, then this is the processs you should go through.

My basic thinking is that the diagnosis will be retarded timing (just as bad as way too much at idle) will be overheating it due to vacuum at idle, A base advance figure of 12 degrees can change under A/C load. Redcued timing was how the old emissions engines got unpopular, they made a lot of heat.


Know that:

1.Electric fans require upgraded 130 Amp alternators to get anywhere near the stock low blade number fan pitch.

Old Blade fans always create the required wind rush. Electric fans "man" enough for the job cosume electricity, and also require other throttle kicking stratergies to control idle.

2. A fan shroud always helps, but they weren't standard, and the plastic versions don't look good. A well made Heating and Ventilation company made shroud would look good, but its your choice.

3. A free wheeling viscous fan from Hyden might help, but its non stock, and a long shot. Its got satisfactory wind rush from idle to about half speed. After 3000 rpm, there is awlays enough mooving air, and it free wheels.

4. Based on the load they place on an engine, even a good modern Sanden, all A/C units shoulds activate a carb mounted Vac Operated Throttle Positioner, or a Solenoid operateed kicker. Like the 1980-1983 1-bbl 3.3 throttle kicker, operated by a orange soleniod.

5. Your Autolite might not have the one that Tecumsah or York A/C Mustangs came out with in 1966. It allows the advance and idle and air fuel mixture to be adjusted better. Holley sells one that can be hidden away, but it needs to be done right to work properly. Holley make a 46-74 item.
https://www.holley.com/products/fuel_sy ... arts/46-74
http://documents.holley.com/20-9inst.pdf.



6. You don't have to opt out of your Load O matic, but you can convert it to electronic points, and customise the advance, or go Durapark, HEI, or just presist with it.


#2 by wsa111 » Tue Mar 14, 2017
viewtopic.php?f=1&t=76428&p=588727#p588727
billythedistributorman@live.com
Talk to wsa111. The ignition advance curve under load your A/C unit and low vac from your cam is your first thing to check.


http://www.automotiveu.com/SolvingOverheating.htm
the amount of additional advance from the vacuum advance should not exceed 10 degrees and not be in before 10 inches of vacuum. When you get too much advance at too low an engine vacuum from the vacuum advance you may get a vacuum advance ping at light throttle. The vacuum source we like for the vacuum advance is a ported source (no vacuum at idle). The reason for this is to avoid the timing change that happens on a vehicle with an automatic transmission when it goes into gear; the vacuum will go lower and cause the timing to change. This can affect the idle speed and quality when the car is in gear, especially if the engine has a hot cam (when the engine is in gear the vacuum is lower and therefore it has to have less timing advance, thus effecting the idle speed).
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Initial timing set at 12. I had it at 16 and put it back to stock spec. If a v8 car can run ac with same size radiator why can't my six? Rad is just an autozone three row.
 
Hi, while that seems to be running hot, consider a few things. Modern engines run hot for complete burn / emissions reasons. Some cars with 195 t stats don't have the fan come on till 210 degrees. Next, an engine with an over bore and higher compression will run hotter than a stocker. So on your car make sure the fan is 1/3 in and 2/3 out of the shroud. The race car guys use a product called Water Wetter, or another called 10 below. We put 2 bottles of Water Wetter in our Saturday night stock car to help keep the temp down. Good luck
 
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