I've been wondering about coolant temps since I have a nice shiny new radiator. Anyhow, the Cummins 8.3 manual indicates a maximum coolant temperature of 212 degrees F. Of course, that's the temp at which water boils. Since we run a 50/50 anti-freeze ratio, our boiling temperature is elevated. So... would this mean that the engine's maximum operating temperature is also elevated? Inquiring minds... Thanks.
jor
The cooling system is also running under pressure which will increase the boiling point to a higher temperature (to approximately 257 F with a 15psi cap). Cannot really address your primary question but I would not think it would be good to run hotter.
Hey, Pierce. No need for such verbosity! ;)
jor
Mine hit 195 on San-Rafel pass in Utah this September. Didn't seem to be a problem. I was pulling a 5000 lb. cargo trailer with the old 8.3. 300hp. My speed was 37 at the top. My buddy has a 450hp and he was at 38 mph at the top. He is heavier but I was pleased.
My apology as I was heading out to the grocery store so just typed no and hit send. Sorry again!!
The 50/50 mix raises the boiling point of the coolant so the hot spots in the cylinder head can't vaporize and create a really hot spot where the coolant is replaced by vapor, which is not effective for cooling and the metal temperature goes way up in a hurry. The engine specs are the same whether it's water or a antifreeze mix. At the design spec temperature, all parts of the engine are at the clearances, the dimensions, etc intended by the engineers so this is the optimum for good economy as well as long engine life. The higher boiling point of a 50/50 mix is good insurance for all seasons as it also cools better than a 100 percent anti freeze solution and at the same time drops the freezing point so the coldest winter won't cause the mixture to freeze, expand and then damage the block/head(s). An added benefit is the corrosion protection the additives in the coolant provide for the different materials found in the cooling system.
Water is the only liquid that expands when heated and also expands when frozen. So, frozen water (ice) is less dense than when not frozen.
OK, owe you a beer or two when we meet. :))
Pierce
When I had my Dynasty it would go up to 210 degrees and then stop there. I think that is when the fans went into high speed. It
never seemed to be a problem. That was and 8.3 engine.
No still 212. Your just back to a fresh starting point. Very desirable. I'm sure we all have core envy
Scott