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Discussion Starter #21
Still not stationary, especially not when the money is on the line.
Stop assuming that you know more than someone who has a whole lot more experience in what he's talking about.
Dang man, I'm just trying to support Gputah. I was kinda hard on him before.

Re. a whole lot more experience. If the issue is Gputah's reference to racing, ah, I've been racing cars for 15yrs. I have >600 track days. I build the engines for my cars. A whole lot more experience than whom?
 

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No, never. I've never even had the coolant hit 230deg. I always back off the throttle when it gets that hot. Also, I've not been able to find any info that there is a derate coolant temp. It certainly makes sense that there is, but I've not come across someone that says he found the temp. It would have to be someone with a big oil cooler like you. That would let us rule out oil temp as the cause of the derate.

I've never paid much attention to oil temp. As long as I'm not near the oil derate temp <shrugs shoulders>, I just don't care about oil temp.
This explains why you're looking for the cure to a non-existent problem. Coolant temps aren't the issue when towing. Oil temp is.

Running at 9º ambient temp I could get my oil up to 210º with all 4 flaps closed on the grille cover, restricting air to my gynormous oil cooler. Open the two bottom flaps and the oil temp quickly drops to 170º as air hits the oil cooler. Tell me again how oil coolers are ineffective.

My oil cooler has lowered my coolant temps across the board. I don't think a larger radiator will do the same for oil temps. I think you'll likely see a very miniscule drop in oil temps, if you were even watching them and had a baseline.

I tow heavy and often, never been left wishing I had a better radiator.
 
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Discussion Starter #23
This explains why you're looking for the cure to a non-existent problem. Coolant temps aren't the issue when towing. Oil temp is.

Running at 9º ambient temp I could get my oil up to 210º with all 4 flaps closed on the grille cover, restricting air to my gynormous oil cooler. Open the two bottom flaps and the oil temp quickly drops to 170º as air hits the oil cooler. Tell me again how oil coolers are ineffective.

My oil cooler has lowered my coolant temps across the board. I don't think a larger radiator will do the same for oil temps. I think you'll likely see a very miniscule drop in oil temps, if you were even watching them and had a baseline.

I tow heavy and often, never been left wishing I had a better radiator.
Coolant temps are an issue for me when towing. Happy to hear that they are not an issue for you. I am oriented on staying in the optimum temp range for the engine, as defined by thermostat behavior, and you are oriented on oil temp causing derating. We are oriented on two different things.

Oil temps are/were a problem for you only because by towing hard you made them a problem. When I tow, I slow down when temps go high. So oil temps aren't a problem for me because I make them not a problem.

Re. Tell you again how oil coolers are ineffective. Ok, but this time don't just scan a sentence, really read it.

Oil coolers are effective at cooling oil and I've said nothing to the contrary. However, oil coolers are not very effective at cooling engines, as defined by dropping coolant temp. The reasons cooling oil is not very effective at cooling engines are all in the article. There's been a few reports to the contrary, but when behavior seems in conflict with the science, that indicates we're missing something. One of those things would be more rigorous testing of the reports that oil cooling significantly reduced coolant temps.

Here's an example. About 10yrs ago I installed a larger oil cooler in my race car. It was right in the air blast. I put temp sensors both before and after. What I found is that the oil cooler was responsible for only 2deg of temp drop and that really surprised me. But the cumulative trips thru the oil cooler created a steady state of a pretty significant oil temp drop, call it 40deg. That result surprised me. What I eventually figured out is that what I was observing was the result of oil being a lousy heat xfer fluid and oil not taking much heat energy to the oil cooler. In fact, the oil pan was removing more heat then the oil cooler was.

Each pass thru the oil cooler resulted in a temp drop of 2deg, but since each pass thru the engine (and oil pan) resulted in a gain of less than 2deg, there was a net reduction in temp. An equilibrium was reached at about 40deg lower.

Oil was such a crappy heat xfer mechanism that only 2deg of heat energy was dumped. Oil was so little in contact with the most hot bits of the engine, that it came out <2deg hotter than when it went in. That's a perfect example of oil being a lousy way to cool and engine.
 

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Discussion Starter #25
As a result of statements like this, I've completely lost interest in this thread. I'm out.
Seemed like a fair statement to me. He distorted what I had said about oil cooler effectiveness. I suggested that it was a mistake caused by not reading carefully. If you don't like that characterization, you going to suggest that it was an intentional misrepresentation? That'd be kind aggressive.
 

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You're making what I consider a low coolant temp an issue. We will have to agree to disagree on what we consider an issue.

The whole point of my modifications is to not have to back off the throttle as often and become what I consider to be a nuisance to the flow of traffic.

I'm happy with the results of my oil cooler, which makes my trips a lot more enjoyable.
 
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This explains why you're looking for the cure to a non-existent problem. Coolant temps aren't the issue when towing. Oil temp is.

Running at 9º ambient temp I could get my oil up to 210º with all 4 flaps closed on the grille cover, restricting air to my gynormous oil cooler. Open the two bottom flaps and the oil temp quickly drops to 170º as air hits the oil cooler. Tell me again how oil coolers are ineffective.

My oil cooler has lowered my coolant temps across the board. I don't think a larger radiator will do the same for oil temps. I think you'll likely see a very miniscule drop in oil temps, if you were even watching them and had a baseline.

I tow heavy and often, never been left wishing I had a better radiator.
@ BOUNTY HUNTER>If I may ask, what are you running for an oil cooler? i have everything needed, but would like to see what others are running, I'd love to be able to tie into the original oil cooler instead of removing it and installing an adapter plate.
 

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@ BOUNTY HUNTER>If I may ask, what are you running for an oil cooler? i have everything needed, but would like to see what others are running, I'd love to be able to tie into the original oil cooler instead of removing it and installing an adapter plate.
I'm running this oil cooler: 26 X 7 X 3.5 Inch cooler

Also using a CFT block adapter plate and DeRale 180º oil thermostat.

Not sure why you'd want to tie into the stock oil cooler.
 
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Been looking at coolers a bit myself. It looks like the CTF kit doesn't include the thermostat. Did you just buy the adapter plate and piece the rest together?
No, CFT does not supply the thermostat, I bought that off Amazon. The adapter plate and cooler came from CFT and I had CFT do the install.
 

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Discussion Starter #32 (Edited)
X2 it was an absolute beating just trying to read it, I’ll admit I couldn’t stomach finishing it.
Ram engineer liked it a lot. Said I was entirely correct re. my take on oil coolers vs. radiators.

In the 7yrs I've had the truck, I've written a couple magazine articles on it. I submitted the 2nd draft of this write up to the same magazine. As a fact check sort of thing, they sent it to a retired RAM engineer that does a lot of court cases these days as the resident expert for suits involving RAM engineering.

I talked to the editor re. my struggles to get EcoD fans to understand how cooling an engine works. He is a (car) racing buddy. We shook our heads in bewilderment. Article will come out this summer. I'll tell you the name of magazine when it comes out. Mag wants a follow up article later once it gets hot enough to see how the larger radiator does.
 

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Discussion Starter #33
You're making what I consider a low coolant temp an issue. We will have to agree to disagree on what we consider an issue.

The whole point of my modifications is to not have to back off the throttle as often and become what I consider to be a nuisance to the flow of traffic.

I'm happy with the results of my oil cooler, which makes my trips a lot more enjoyable.
I certainly agree that an oil temp that causes derate is a problem. I note, however, there's not been much discussion re. "why it's a problem." It's not particularly bad for the oil, so why the derate?

The EVIC shows us that the thermostat opens at about 195deg. Most thermostats have a 10deg management range, but lets say it's 15, so at 210deg it would be fully open. The purpose of the thermostat is to keep the engine in it's designed temp range. Hotter than that is outside of the engine's designed temp range. Frankly, I can't understand how you can apparently look at coolant temps at 230-235, shrug your shoulders and say "no problem." Sure, it's not a crisis. Engines aren't blowing up due to over-heat, but our engines being tolerant of repeated mild over-heats isn't an argument in support of "mild over-heats are no problem."

I would like to avoid mild-overheats. I don't really understand why that would be perceived as unreasonable.
 

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Frankly, I can't understand how you can apparently look at coolant temps at 230-235, shrug your shoulders and say "no problem." Sure, it's not a crisis. Engines aren't blowing up due to over-heat, but our engines being tolerant of repeated mild over-heats isn't an argument in support of "mild over-heats are no problem."

I would like to avoid mild-overheats. I don't really understand why that would be perceived as unreasonable.
I'll have to defer to FCA engineers on that one, I have neither the experience or education on why there's a derate at over 265º oil but not at 235º coolant. Surely there is a coolant temp at which a dash warning is activated followed shorty by a derate situation.
 

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Discussion Starter #35
I'll have to defer to FCA engineers on that one, I have neither the experience or education on why there's a derate at over 265º oil but not at 235º coolant. Surely there is a coolant temp at which a dash warning is activated followed shorty by a derate situation.
I would expect, only because it's logical, that we would get a derate from a high coolant temp just like an oil temp. But there's some interesting dynamics in how the coolant cooling rate and the oil cooling rate would react to increased temps.

1. The derate temps could be kinda arbitrary. We would prefer to assume that the derate temps were the result of careful analysis, but often things like that get set w/o much actual study. So maybe the oil derate temp really ought to be 10deg higher. Certainly the oil would tolerate higher temps.

2. The system for dumping heat from coolant that is getting too hot is very different from the system that is dumping heat from oil that is getting too hot. The ability of the oiling system to dump heat is pretty limited. It can dump a little heat to the coolant via the oil-water heat exchanger, but most heat that gets dumped from the oil is from the air blast on the oil pan. The oil pan can dump heat from 240deg oil to 90deg ambient air, which is a helova lot more efficient then trying to dump heat energy from 240deg oil to 220deg coolant. Also, the oil pan has a lot more surface area for heat xfer than the oil-coolant heat exchanger.

In contrast the radiator, with all it's surface area, is dumping heat from the coolant as best it can. Once the thermostat is fully open, call it 210deg on the EVIC, the coolant system is maxed out--except for one thing. As the coolant gets hotter, the radiator gets more effective. This is because heat xfer is proportional to the difference in temp and 235deg coolant is a fair amount hotter than 200deg coolant. If ambient is 90deg, then the hotter radiator will be about 25% more effective, which is a lot.

Sure, the oil pan would cool 260deg oil more effectively than it would cool 230deg oil, but the increased efficiency isn't as noticeable because the oil pan just doesn't have enough surface area to do a lot of cooling. The only reason the oil pan kinda works to cool oil is that the oil isn't moving much heat from the engine.
 

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Please stop comparing a N/A gas engine to a diesel there very different. Diesels run way hotter in cylinder which is why egr is required on diesels but used on few gas engines. These engines use aluminum pistons which transfer heat extremely well and are cooled via engine oil with piston cooling nozzles. Vm motori set a max oil sump temp for the oil of 284 F and fca had to follow that. The large diesels I used to work on had almost zero air flow across the oil pan and used coolant to oil heat exchangers which managed a delta of 5-10 degrees but you claim thats not possible.
 

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Discussion Starter #37
Please stop comparing a N/A gas engine to a diesel there very different. Diesels run way hotter in cylinder which is why egr is required on diesels but used on few gas engines. These engines use aluminum pistons which transfer heat extremely well and are cooled via engine oil with piston cooling nozzles. Vm motori set a max oil sump temp for the oil of 284 F and fca had to follow that. The large diesels I used to work on had almost zero air flow across the oil pan and used coolant to oil heat exchangers which managed a delta of 5-10 degrees but you claim thats not possible.
Re. stop comparing. The design of the cooling systems, from block and head water jacket to radiator is pretty close to identical.

Re. diesel engines run hotter. And it's a water cooled turbo. So maybe it should have gotten a bigger radiator then the Pentastar.

Re. max oil temp is 284deg. In the other thread you said the oil derate temp is 269deg, so I'm confused. High temp deration, oil or coolant? Is derate temp different than max temp?

Re. can't cool fluid with only a 5-10deg delta. I'd have to know more about the use case. If there seems to be a disconnect between the physics and what we're observing, it's always because we're missing something. The pic below shows the heat xfer equation for conduction and a quick glance shows that heat xfer is proportional to temp delta and surface area. So if you've got a small temp delta, you have to make up for it with huge surface area. There is just no getting around the fact that as delta T goes down, surface area has to go up. A heat exchange system wouldn't get designed with a small temp delta unless there was no other choice because making something big is expensive. In heat xfer, one always gets the two temps as far different as you can because that allows for a small heat exchanger.


88877
 

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@Gputah last time I checked, 1000 hp race cars are not stationary. I also know an engineer that didn't get it right usually doesn't admit it until their boss has to pay to fix their screw up.
Literally laughed out loud hearing my dad's voice here. 12th grade education and lineman w/ Florida Power & Light who rose to Division Superintendent in charge of new high line (500kV) construction across SW Florida.

Constantly had his MS prepared engineers redo plans because their school taught theory was not field reality. I suppose pioneering 'bare handing' in FL in the 1970's provided more 'education' than an academic classroom education LmAo.
 
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The max temp per vm motori of 284 is sump temps aka in the oil pan. The derate temp of 268 F is post oil cooler which is whats measured. When coolant comes back from the radiator it’s typically around 30-50 degrees lower than whats displayed on most engines the displayed temp is at the return for the water pump which is hottest.
 

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As a result of statements like this, I've completely lost interest in this thread. I'm out.
Actually, many context clues are observable here...if the avatar doesn't give it away, simply observe the redundant frequency of the authors selection of 'I' and the utilization within :ROFLMAO:.
 
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