Technical Running hot with A/C

Guys, thanks for all the suggestions and opinions. Solving a problem is usually better when there are more brains thinking about it. I'm going to change the thermostat to a Robert Shaw 195. After giving the temp guage a closer look, it appears to run at 195 with the A/C running. I had contacted my engine builder and they said that a 180 or a 195 would be adequate. I always ran a 180 but times are a changing.

Thanks again, and if you're ever up in the Amarillo area, give me a shout!
Jon delPozo

 

I have the same setup .zips riser flex fan and a 17 " electric fan in front of a walker rad. It would run around the same temps as yours. this summer I changed to a 160 degree thermostat which is what zipps recomends . my temps went down about 15 degrees. only had to use my elecric fan one time this summer on a 100 degree day in traffic.

 

All the hotter thermostat is going to do is let the engine get to 195 before opening instead of 180, it will not run any cooler or hotter then it does now. Once a thermostat opens, it is no longer in charge of the cooling if the radiator cannot get rid of the heat. Air flow is where you need to be looking. A smaller water pump pulley will speed up the fan and move more water, which is what you want for A/C equipped cars.

 

Joe H is right,once it's open the only thing that will regulate the temp is air flow. Make sure that the area between the grill and radiator is sealed and every bit of air goes through and not around or over or under the radiator, divert all the air flow to the rad and you will solve any problems.

 

I was told once by a very knowledgeable radiator man that if you aren't losing water it's not too hot. I have used that rule and not found it to be wrong. He also told me no two gauges will read the same. I feel this is true too. You have the good stuff on there 200 is ok if you aren't having to add coolant.

 

200 is fine with A/C on in traffic on a hot day, with a 16 psi cap boil over will be around 260 so you should be fine. Bob

 

200 is not too hot. For every pound od pressure you raise the boiling point 3 degrees. So instead of boiling at 212 a 10 pound cap would put it at 242 you have no heating problems with this car

 

200? Brrrr. My flathead hits 200 by the end of the driveway.

 

You are fine at 200. New cars run 215 all the time. Many a hot rodder would be tickled to have your problem.

 

This is mostly correct. Technically, overheating is the condition when coolant boils, if you keep it in a liquid state it's not overheating. However, old head gaskets may not fully agree with that, and they may fail prior to boil over depending on the pressure in the system and the age and weakness of the gasket and the sealing surfaces. But with all that said, 200 in a SBC is nothing to be concerned about. A SBC will run 100,000 miles at 200F, no problem. And the guys above me talking about the 195 thermostat are also correct. Changing the thermostat from 180 to 195 will only increase the temperature point that the thermostat opens, it most definitely WILL NOT help the condition you think you have.