[DFS]

Have a 289 w/Alum. Big Block Rad. 3000 CFM Electric Fan (Pulling) with Therm.Coupler. After engine warms up temp stays around 185 - 190 ºF and if I turn on A/C it will increase 3 to 5º. At dead stop in traffic it approaches 200ºF or a little over. I admit that I am a little paranoid about over heating, the fluid is 100% Coolant. the motor is actually a 66 with a "Cam" and the heads have been worked on a little, just a basic 289 with some help and a std. C4 Auto Trans. Should I be concerned. Motor has 1000 mi. on complete rebuild. car was completely rebuilt as well. Not to mention temp here in July Aug is always in high 90"s and so is the humidity. Should I be concerned, are am I just temp paranoid since i burned up a motor back in the 60's but not paying attention to the temp. gauge.
DFS

[jim293]

Welcome to the site. Lets try your question in here.

[Razgrizs]

When you say 100 percent coolant do you mean 100% antifreeze? If so , you should have a 50/50 mix of water and antifreeze.

[Ivy66GT]

First, your temps sound about right; 200 degrees is nothing to worry about with the A/C running. The system is designed to not boil until about 250F.

However, running straight antifreeze makes the car run hotter than if you have the correct 50% mix. Add half water and it will run cooler. With 100% water it runs cooler yet...until it either freezes or corrodes the engine/radiator and starts to plug up the system.

[DFS]

Originally Posted by Razgrizs

When you say 100 percent coolant do you mean 100% antifreeze? If so , you should have a 50/50 mix of water and antifreeze.

Yes it's 100% Antifreeze, but from the feed back I think I will change to at least a 70/30 mix with 30% being distilled water.

Many thanks for all the feed back.
DFS

[DFS]

Originally Posted by Ivy66GT

First, your temps sound about right; 200 degrees is nothing to worry about with the A/C running. The system is designed to not boil until about 250F.

However, running straight antifreeze makes the car run hotter than if you have the correct 50% mix. Add half water and it will run cooler. With 100% water it runs cooler yet...until it either freezes or corrodes the engine/radiator and starts to plug up the system.

Yes I running straight Antifreeze but I will change to a 70/30 this week, the 30% being Distilled Water.

Thanks
DFS

[DFS]

Originally Posted by Ivy66GT

First, your temps sound about right; 200 degrees is nothing to worry about with the A/C running. The system is designed to not boil until about 250F.

However, running straight antifreeze makes the car run hotter than if you have the correct 50% mix. Add half water and it will run cooler. With 100% water it runs cooler yet...until it either freezes or corrodes the engine/radiator and starts to plug up the system.

Thanks - I am going to change to a 70/30 this week the 30% be distilled water and
see how that works.
DFS

[DFS]

Originally Posted by jim293

Welcome to the site. Lets try your question in here.

Thanks recd. many answers and I'll make some changes this week
DFS

[DFS]

Originally Posted by Ivy66GT

First, your temps sound about right; 200 degrees is nothing to worry about with the A/C running. The system is designed to not boil until about 250F.

However, running straight antifreeze makes the car run hotter than if you have the correct 50% mix. Add half water and it will run cooler. With 100% water it runs cooler yet...until it either freezes or corrodes the engine/radiator and starts to plug up the system.

Thanks....as you can see I received a good response form many people, thanks all.
DFS

[Zaikur]

Originally Posted by DFS

Yes it's 100% Antifreeze, but from the feed back I think I will change to at least a 70/30 mix with 30% being distilled water.

Many thanks for all the feed back.
DFS

A 70/30 mix doesn't really do any good either, 50/50 really does give the best results. Your temps will probably drop by a good 10 deg that way. And why use distilled water? Every mechanic I know uses regular tap water.

[Ivy66GT]

The only reason to use a 70/30 mix would be if you expect to need freeze protection to -84 F. I doubt it gets that cold in Arkansas. The boiling temp with 70/30 is about 10 degrees higher than 50/50 but if it makes the engine run 10F hotter than you gained nothing while paying more for antifreeze you didn't need.

A 50/50 mix won't freeze until -34 F and I think you will be pretty safe.

Whether or not to use distilled water is a personal thing. I never do, but then I know some who think its cheap insurance to not get unwanted 'stuff' in the cooling system. It depends somewhat upon the water quality wherever you live. If you do use bottled water make sure it is truly distilled and not de-ionized since the later can have de-ionizing chemicals in it which you don't want either.