We should have made this a poll.

 

Seems to me that we should take in account not to collide with the ECU algorithms we do not know in our vehicles.

I mean, no matter how cool we want our engines to run, the fuel/air mixture should not be pushed into rich conditions by the ECU.
As we do not know at what low temperature limit it occurs, establishing a low temperature limit could be necessary also.

If we like the engine coolant at 80C = 176F, the enrichening should for sure start below that, or fouling and consumption may be detrimental.

Does anyone know for sure at what coolant temperature there is no enrichment ?
Let's guess it is 85C = 185F. No matter how cool we want the engine to run; should not be under that temperature.

Now back to the upper limit :

Water with zero antifreeze and zero pressure cap boils at 100C = 212F
Water with zero antifreeze and 14psi = 1 bar cap boils at 118C = 245F

Helpful charts:
----> http://2.bp.blogspot.com/-srZWWqnH5A...LESCOPIC2B.gif
----> http://hellafunctional.com/wp-conten.../11/boilpt.gif

Does this work for you ? ---> Speed-Wiz coolant calculation
It is frozen for me.

Any knowlegeable and respected member to set a temperature figure from the opinions given please ? If discussing further deserves revising, well, let's revise the "overheating" definition figure then.

I still believe overheating definition should be around ~111C = 232F; which is a figure we very dislike our engines to run.

 

I am neither a knowledgeable nor a respected member. However, I would now like to revise my temperatures, above, down by 2 degrees for each of my categories (irritate, panic, pull over and tow; reduced to 210/218/230). With inline mod, 180 tstat and new radiator filled with green, I usually run at 185-190.

 

For you guys running an UltraGauge on board; can you stablish at what coolant range/rising temperature the stoichiometric 14.7:1 mixture starts being correct/locked ?
That at least can tell the lower (coldest) limit we should wish for.
I do not own an instrument that tells real-time readings of ideal combustion.

Please help if there is any readings that show a dangerous engine state at higher temperatures, to see if can be referred to as overheating. Or if there is a mixture reading where starts being lean. I do not know what information can be obtained from an UltraGauge to help the definition, if any.

I do run a 82C = 180F in-line thermostat with no bypass and a massive radiator, and engine runs pegged to exactly that. But perhaps is healthier for efficiency/performance/economy a higher number, if we can keep it safely steady all the time.
Thermodynamics says 'The more heat is created and the more an ICE is cooled, the better the efficiency' (Delta t).

 

Dammit. Just saw this. And already on the bus. Anyone who has a few minutes, it's the temp where we enter closed loop.

 

Any of you guys reporting these lower temperatures running a 4.6 (without the oil cooler)? I'll easily see 216 if climbing and under load with the AC switched off. (new Genuine 180TStat, New Nissens Radiator, new hose kit, new expansion tank and cap with green coolant)

 

UUGGGGH!! LUCKyyyyyy!

 

At 216F you've got a problem. I had an issue with temperature spikes with the stock set up. I went to the inline mod and have never looked back. My trucks runs fantastic and my engine doesn't tick anymore since I've done this mod. I run 183-186 most of the time. It's also nice to not have a super hot engine compartment when you need to check something out. You can always tell if shes running hot because the aluminum radiates such heat. The mod is so easy and totally worth it.

 

It's not clear to me that an inline mod would produce the desired effect. I see the types of occasional spikes that you mentioned caused you to switch to the inline mod but this is different. This is a steady climb in temperature due to the following conditions:

• Climbing a long, steep grade at speed (~65mph, from around sea level up to 4600 ft)
• heavy truck (arb bumper, steel rear bumper, dual battery setup, full SD rack, 140 pound roof top tent)
• stock gears

Once the temperature starts to climb, the TStat is already fully open, the cooling system just can't keep up. Pulling over allows the temperature to return to normal. If i slow down to say 45mph, temps will cease climbing depending on the severity of the grade and often begin to drop.



Normal freeway and town running, with the OEM setup I run between 186-194



I've seen a thread where the problem turned out to be a malfunctioning cat. I also had a theory that gearing might come into play, but I see that you also run 32" tires. Where do your temps sit when climbing a long, steep hill? (more than a couple of miles)


Anyways, didn't mean to hijack the thread. I have my alarms set to 210 on the UG and I'm looking for a spot to pull over safely by 220.