RangerGress
Senior Member
- Joined
- Mar 9, 2014
- Posts
- 106
- Reaction score
- 33
- Location
- Savannah, GA
- Ram Year
- 2014
- Engine
- 3.0l turbo diesel
Sorry to dredge this up, but one reason nobody has stated not to change the mix in your cooling system is because it also changes the BOILING point, not only the freezing point. More water- easier to boil over. The coolant temp in these trucks handles a lot more than just cool the engine. Keeps the transmission temp in the optimal range, oil, everything. Oil absorbs heat as well, and that is also part of the design- the oil and coolant are designed to keep that engine in the sweet spot for temps. If it's running too hot, you're going to know it. The temps listed wouldn't alarm me at all.
The difference between the boiling point of a 50/50 solution and a 25/75 solution isn't much. Something along the lines of 10deg F IIRC.
The coolant system keeps the transmission cool, how?
In any event, this is all kind of overcome by events. Once it became clear that the thermostat doesn't fully open until 228deg, any concern re. 222deg went away.
Oil doesn't do much to cool water-cooled engines. If you look at the design of the block and the heads you'll see that most of the combustion chamber is surrounded by the water jacket. This is the design that dumps the heat of combustion into the coolant. The reason the oil gets hot is that it just happens to be running thru little passages in the hot block and head, which is different then being in cavities that surround the combustion regions.
Also, oil is a lousy heat exchange medium. It's around half as effective as water. That's why oil coolers can cool the oil a fair amount, but the cooled oil doesn't cool the engine much. Hmm, how to explain that.....it's as hard to get the heat energy out of the oil as it was to get it in. Years ago I was doing a lot of experiments with the oiling system of my BMW race car. I installed an aftermarket oil cooler 3.5x as big as OEM and put temp sensors before and after. The temp delta was only 4deg between inlet and outlet, which is obviously not a lot. What I didn't expect tho is that the over all temp of the oil was reduced significantly, like 25deg or so, which is a lot. That would seem to be a contradiction but what was happening was that pulling out 4deg in the oil cooler was enough to significantly lower the steady state temp of the system because the oil just wasn't pulling that much heat out of the engine.