TRCM, your huge missed point in your assertion that "it flows faster and doesn't have as much time to cool off in the radiator" is that it also flows faster in the engine and doesn't have as much time (per coolant "lap") to pick up heat there. It just does more laps in the same time to make up for that, because that's how physics works. Sorry.
Don't apologize, I know exactly what you are saying....the problem is, in the case of the OP, the heat transfer into the coolant in the block is greater, and since you brought up physics, there are many more low flow areas & eddies in the block that let the coolant stay in the 'heat absorption zone ' longer, than there are in the radiator, where the heat is given up.
The net result is, per 'lap' the coolant may absorb 15 deg of latent heat in the block, but only give up 10 deg in the radiator....which gives a net gain of heat....which is bad.
Some engines have external thermostat housings with a bypass hose back to the WP from the hot side of the stat so that there is still coolant flow over it when it is closed to keep the thermostat at the same temp as the water jackets so it can do its job. Good examples include the BMW M10 and the GM 2.2L OHV in the Cavalier. If the system is set up this way, removing the stat can in certain cases result in increased flow through the bypass and less through the radiator, resulting in overheating. However this does NOT apply to the 4.0 and a 4.0 will not overheat if you remove the stat, sorry.
Stop apologizing...I never said removing the t-stat in a 4.0 would cause it to overheat... I was and still am talking in general about a closed loop cooling system (or as closed loop as a cooling system is in your average car/truck), not being specific about any particular engine.
A friend of mine tho would likely tell you you are wrong, as when he did remove the t-stat, he had overheating problems. All he did was put it back in, and they went away. His is a 2000 model 4.0.
External thermostats with bypass hoses and coolant cavitation caused by extremely high flow can cause overheating. Mere high flow from a removed thermostat will not
unless it results in cavitation.
Hmmm...there goes that condition again that makes it do something else beside what you are trying to convince us it does.
Like I said, I will be testing this soon. Feel free to argue all you want, I've said my piece, I agree with AIBandit, and will be happy to eat my words if my test proves me wrong.
I already gave my experience on this....but no one wants to believe me...so do as you wish. I KNOW what happened when I did it. Not arguing, just relaying information...take it or leave it. I use to say the same thing you are, till I tried it and had to eat my words.
Edit: also, your example of walking vs running is spurious for two reasons. It is an open system not a closed one (you are passing through air you will never see again, thus its exit temperature is irrelevant) and you expend energy increasing the flowrate. Both affect the results.
When you walk or run thru the room, you are indeed going past/thru air you will never see again. The air forced thru the radiator to cool the coolant off is also air you will never see again. So what's the difference ??
Remember, YOU are the coolant, the air in the room represents the air that is forced thru the radiator by the fan or vehicle motion, and the room represents the radiator, not the other way around.
And true, you do expend energy increasing the flowrate...but NOT in the radiator where the heat transfer is occurring that is causing the overheating....so for any real purpose, the flowrate is constant and energy is not being added.
I'm done....yall do what ya want....I tried to tell you what happened when I & others I know did this 'experiment' of trying to improve our cooling systems using a higher flow pump, or using no t-stat, or whatever device was the new gimmick. In all cases, we ended up using the stock components with a bigger radiator to make things better.
You don't want to believe me....I get that, so I'm gonna quit worrying about it.
:worship: