1950 Overheating

[sconnors]

Wondering if someone can shed some light on this problem. I have a 1950 Buick Special 248. The car runs great and the temperature is always fine EXCEPT when sitting for a period in traffic or waiting in a line at a car show etc, the car overheats. Today I drove 35 miles to a show going between 55-65 mph and the temperature was fine. Parked the car at the show for a few hours and they were going to have a parade of all the old cars. I started the car up and sat in line for perhaps 15-20 min and she overheated. Once I pulled her out of the line, shut her off and let her cool down, I drove her home and she was fine all the way.
Anyone have a similar problem on a 1950 248? I'm wondering if I should start with the thermostat, water pump, or if someone else has any other ideas.
Thanks
Scott

[Straight Eight]

First off remember there are no original equipment electric fans on these old girls, and idleing for 20 minutes will cause the best of them to overheat. You gotta shut her down if you are not moving.
Of course you could get an electric fan and put it on the radiator, they do come in 6 volts.
You could also put in a 160 thermostat or cooler. Add "Water Wetter" to the coolant, mix fresh antifreeze and water with a minumum of antifreeze, then add more antifreeze in the winter time.
You could also open up the port holes so the hot air can escape the engine compartment.
There are all kinds of things you can do. You havent mentioned where the heat needle was on the dash while you were on the highway., and when you pulled into the show.

[sconnors]

The heat needle was dead center the whole trip up ad when I pulled into the show. After she was shut down for awhile and I started her up to join the parade she was cool.

First off remember there are no original equipment electric fans on these old girls, and idleing for 20 minutes will cause the best of them to overheat. You gotta shut her down if you are not moving.
Of course you could get an electric fan and put it on the radiator, they do come in 6 volts.
You could also put in a 160 thermostat or cooler. Add "Water Wetter" to the coolant, mix fresh antifreeze and water with a minumum of antifreeze, then add more antifreeze in the winter time.
You could also open up the port holes so the hot air can escape the engine compartment.
There are all kinds of things you can do. You havent mentioned where the heat needle was on the dash while you were on the highway., and when you pulled into the show.

[Straight Eight]

The fact she stayed in the middle seems to indicate nothing abnormal, now you just gotta make a few adjustments . Evans makes a 6 volt fan, push or pull depending how you install it.

[njlimbaugh]

You've probably done this already, but one more thing to check is the fan belt tension. Fans don't do anything above about 10 mph, but if they slip at idle or low speed that will contribute to overheating