OVERHEATING
Thats fine I've read the advertising and the arguements for and against. some of it makes for compelling reading and some of it is the usual Ad. Man BS.
Just gotta chose which narrative you are swayed by... :) then try and find some solid science to back it up... and thats where the problems start, finding anything truely indpendent to back up or contradict the claims is nigh on impossible.
i can't find any good science to suggest its better and I can't find any good science to show its worse.
so it comes down to cost, availability and convienience. the first two are the killer for me.
Dave
Ok, one more time. I use the term YOU in the general sense, not as in YOU personally.
You have a fixed cooling medium temperature to work with. That’s ambient temperature. So for ***** and giggles we’ll say that’s from about 20-110 degrees Fahrenheit.
That’s ALL you get.
Again, for ***** and giggles we’ll say you love to run your engine at 195 degrees.
Now we have the temperatures we are working with.
So, let’s say that it’s a 60 degree day and you are rolling down the road at 195 degrees. You have a 135 degree temperature difference between ambient and coolant temperature. Assuming you have a 195 degree thermostat it is partially closing at some points to maintain your 195 degree temperature.
On a 100 degree day, you now only have a 95 degree temperature difference. You have less ability to remove heat from the coolant. Now the thermostat is wide open all the time and the coolant temp climbs to 205 degrees because the ONLY thing the thermostat does is set the MINIMUM coolant temperature.
Now you come on here and say my engine overheats at 205 on hot days. One response is it’s not overheating. And that’s true. It’s isn‘t OVER heating but it’s too hot. IMO 195 is too hot for a performance engine but that’s another topic for another post. And you just don’t want the engine at 205 degrees.
The other stock in trade answer is what you gave. Slow the coolant down so it stays in the radiator longer. Obviously at first blush that makes perfect sense. But it’s DEAD wrong.
Since (in this example) we are dealing with a 95 degree temperature difference (I should be saying delta but you get the point) the longer the coolant stays in the radiator, the longer the coolant stays in the engine. And when the coolant stays in the engine longer, it picks up more heat. Since you only have a 95 degree temperature difference, the coolant staying in the radiator doesn‘t do a pinch of **** of good. In fact, it’s *** backwards.
Think it through. The coolant is in the block longer, so it picks up more heat. The radiator just can’t shed any more heat no matter how much longer the coolant stays in it because the difference in temperature between ambient and what is coming out of the engine isn’t enough to effect a coolant temperature change.
That’s exactly what happens and it shows up in the difference in coolant temperature at the gauge and the temperature rating of the thermostat.
If your cooling system is running at peak performance your temperature should be at or within 5 or no more than 10 degrees of what the thermostat rating.
How many times do we see guys running a 180 thermostat but the gauge (assuming the gauge is accurate) says 200??? All the time.
Thats an example of what happens when you don’t have enough air flow, coolant flow or both.
Again, thinking it through and now understanding that keeping the coolant in the radiator longer also means the coolant stays in the engine longer, collecting more heat we can now look at the other side of the equation.
We speed up the coolant (and if you are running a mechanical fan you are speeding up the fan too which is a GOOD thing most of the time) so that the coolant isn’t in the engine as long, and since it’s not in the engine as long the coolant has a lower temperature going to the radiator.
Now we give the radiator a better temperature difference (lower coolant temperature out of the block requires LESS heat to be removed by the radiator and ambient temperature) to allow the system to shed heat.
I can’t make it any more plain than that. Leaving the coolant in the radiator longer means that same coolant stays in the engine longer and therefore is picking up more heat that the radiator and ambient temperatures have to deal with.
If you are constantly running at ambient temperatures of say 80 degrees or lower then you can have more errors in the system and not pay for it.
But, if you don’t want 190 plus degree coolant temperatures (I don’t, it’s too hot for performance) then it’s even more critical to get the coolant out of the engine sooner to the temperature difference is as great as it can be.
We can’t control ambient temperatures but we can control how long the coolant stays in the engine, how big and how many (or how few) cores the radiator has and how fast we turn the water pump (which controls along with the thermostat how long the coolant stays in the engine and radiator) and all that controls the operating temperature of the engine.
So the TL;DR is speed up the coolant and let the thermostat set the minimum operating temperature and the radiator and ambient temperature control maximum operating temperature.