How hot is too hot?

The_Josh_Bear

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...you might be able to cheat in the mean time and bend the thermal spring in the front of the clutch to cause the fan to come on sooner"

This was my first thought too to fix the engagement time. I've read that turning it 180* tighter will make it come on faster. (I think it's tighter that does it). Then do it again if it's too high still.

What is your EGTs running?

+1
I don't know if you did the 6.9 coolant mod, but I'm guessing not. The 7.3's will always run hotter than the same setup on a 6.9 because of anemic head cooling.

Boiling point for 50/50 coolant at sea level with a 15 psi cap is 265*F. At 250 I'd for sure be backing out of it because localized hot spots in the cylinder head will be well over that temp.

If you want to get scientific on it, measure the coolant temp at the lower radiator tank. Most have an npt petcock you can screw out and install a temp bung in it's place. That will tell you if the radiator/fan is functioning adequately. Check your gauge in a pot of boiling water too, I've seen them off as well.

+1 well said!
 

Black dawg

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I really dont think you can hurt one of these based on coolant temp, as long as it isnt boiling. I would be worried about the oil at that temp though and if it isnt a better quality oil it may get cooked into the ring lands.
 

Farmer Rock

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I really dont think you can hurt one of these based on coolant temp, as long as it isnt boiling. I would be worried about the oil at that temp though and if it isnt a better quality oil it may get cooked into the ring lands.
At 250 I would be worried about head gaskets and possibly warping a heading if it gets much hotter than that.



Rock
 

Oledirtypearl86

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Iv had mine at 240 for over an hr with egt at 1000 and it didnt warp anything I will say once at the top of the pass we pulled over and the truck needed to catch her breath for abpit 30 min as I had the heater going full bore and allthe doors and windows open. And she still runs great it was so hot in the truck my buddy threw up trying to drink water we were all heat soaked
 

03wr250f

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Few thoughts,
1st what is that fan out of or what is the sort number on that fan?

2nd when was the last time you flushed the cooling system? Like spend 3-4 hours running water thru it till it comes out spotless then flush with distilled then fill with coolant?

3rd I'm guessing you have all the usual
3 or 4 core rad, new motorcraft stat, hoses, water pump, new fan clutch etc
Please update what you have and haven't done

4th. What motor mods and how much fueling

5th how fast you pulling, ambient temp, how much of a grade and what are you pulling


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laserjock

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Lots of good thoughts here guys. Let me answer some questions and toss out some observations.


Yes it is a champion radiator. Having just cut a big hole in the tank I don’t think there is any manufacturing defect. However, I think your flow comment could be on the money but not a fault with the radiator.

I am now running a CDD 110 pump now. Fueling is more than before for sure. Truck has tons of power and it’s frustrating as hell not to be able to use it. I am having problems with my timing meter so I’m not confident with what my timing is. I think I’m at about 8 degrees but I don’t trust my meter currently so that’s a question mark I hopefully can answer soon. As far as EGTs, I typically lift at 1200. My probe is in the manifold between 6 and 8 which is supposed to be the hottest location. I rarely get that warm because the water temp climbs so fast.

The fan is off of a 6.4 psd which does have the same rotation as the idi. The 7.3 and 6.0 psd are backwards. So you are spot on there.

Other notes about my setup. I am running a water cooled Garrett turbo so the turbo is adding to the heat load a bit. I am running a 14 lb cap with fleet charge. It also has water wetter in it I think.

I typically shoot to top the bigger mountains in 4th gear at around 65 mph. With 3.55 gears that puts me at 2500-2700 rpm. On the mountains I am not flat on the floor anymore.

So here are some observations.

The thermal clutch is definitely working. At 230 the fan locks up and I know it is because the belts start squealing. [emoji849]

The fan and shroud are definitely doing their job because the truck cools really fast. To me that says we are definitely not heat soaking the radiator. I can be back on the thermostat or below in a mile or two after topping the mountain.

I currently cannot run over 900 EGT for much time because that’s where the water temp starts climbing really fast. So it’s basically a race up the mountain to get to the top before it gets too hot. Going across the mountains on I-68 is not conducive to that. Being limited to those kinds of sustained EGT would seem like a problem. I have been told by guys they run the over 1000 all day long and honestly I’ve never been able to do that.

My sender is in the factory position. My factor sender in the dash is in the rear of the pass head. If you watch, the dash gauge rises much slower than the autometer because the dash gauge is getting the water pretty early in the trip through the engine as opposed the the autometer which is seeing the hottest point. This tells me the radiator is doing it’s job for the most part.

So the long and the short of it to me is that it seems like I have enough cooling capacity with these mods. It cools much faster than it did but even before I could cool it down quick just by lifting. I think the problem is that I need to smooth out the spikes in the temp and I’m beginning to think it’s the thermostat not flowing enough. It is a new motorcraft thermostat. I’m seriously considering bypassing some water around the thermostat to see if that makes any difference. I’m thinking maybe a remote thermostat to regulate the bypass but still noodling that around.

I know I need to get the timing verified. That could be an aggravating factor.


In the long term, I can see a serp swap in my future to turn that giant fan.

I also think the hot side of my turbo plumbing is hurting me a bit. I may consider re-doing that up the road.
 

ifrythings

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How did you get the 6.4 fan to fit?

Does you lower rad hose have the spring in it to prevent collapsing?
 

03wr250f

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Couple thoughts
How did you fit the 6.4 fan? Did you trim it down?

I see no intercooler, that isnt helping you, how much boost are you making pulling the hills?
Water cooled will add heat slightly, but should also produce cooler boost slightly.

I have heard many times on higher hp idis egt is not so much the issue because as you are finding coolant is more of a issue

Verifying timing will help, but I found the best timing was get it close then drive it, find the most boost, lowest smoke and lowest egt for the same driving conditions will produce the best power and fuel eco. That will result in lower egts from a more complete burn.

I think working on a fan clutch that locks way sooner, say 210 is the biggest thing to go after first imo.

I dont think a second thermostat or a bypass will help
Might consider a flo-kooler water pump that flows more volume if that's the route you want to take.
And no one has tried one on a hot idi so far. It would be cool to know

I do think that rushing up the hill trying to beat temps isnt helping.

What are you hauling and how steep of grades?

My setup is very similar to yours(110cc r&d, injectors, s257, intercooler, water ****, champion rad, zf5, 3.55s) so I am both curious how yours can perform, and how mine will, but also how to make it better so you dont have issues

I think honestly you are trying to go too fast. 65 mph towing up a hill is flying for a idi. Especially since you are basically doing 5th gear with 4.10s

There is a guy on the facebook pages
Cclb, brick fully built motor, 180ish pump stage 3 turbo intercooled with a slide in camper in the bed
6% grade for 13 miles
Egts around 900, 5-10psi boost and 210 coolant temp but he pulled at 45mph.
So yes I understand wanting to use the new power but if your getting to hot maybe see how it does slowing down to say 50 in 3rd or maybe 50 in 4th but I feel like egts will be high due to lower rpm


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chillman88

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How did you get the 6.4 fan to fit?
How did you fit the 6.4 fan? Did you trim it down?

https://www.oilburners.net/threads/project-big-red.63615/page-200#post-1080429

I see no intercooler

He's running an air to air intercooler. You should skim through his build thread, it's really good Sunday reading lol. It made me jealous but he put a LOT of love into this truck, even re plated the fasteners!
 

BrianX128

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I currently cannot run over 900 EGT for much time because that’s where the water temp starts climbing really fast. So it’s basically a race up the mountain to get to the top before it gets too hot. Going across the mountains on I-68 is not conducive to that. Being limited to those kinds of sustained EGT would seem like a problem. I have been told by guys they run the over 1000 all day long and honestly I’ve never been able to do that.

This part just stands out to me having read through a good bit of the build thread and reading this thread. I can sit at 1000 egt+ with my ac on going up hills on 90* days and the most I can get to is 210/215. I would melt pistons with egt's before I'd ever hit higher water temps. I wonder how much heat the water cooled turbo is adding to your coolant if the egt's aren't exponentially making your water temp climb.

This is a stupid idea, but have you ever thought about adding a coolant filter / longer stainless braided lines to the inlet and outlet of the coolant feed to your turbo? Cool the coolant down more before it gets there having time away from "everything"? Only reason I think this might be relevant, I have a bypass oil filter setup and my oil temp in the engine can be hovering around 190 on hot days, but I have a second gauge I added to the oil temp once it's ran through 8ft of braided hose, the bypass filter, and 6 more feet of braided hose on it's way back to the oil filler cap, and it will be 30+ degrees cooler before it gets there. Maybe if your coolant had some time away after getting heat soaked by the turbo it wouldn't multiply your engine temps? Just an idea.
 

Booyah45828

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Thermostats are cheap. I know yours is new and motorcraft and all, but if you're leaning towards a faulty thermostat, throw another one in it.

Some food for thought. If the thermostat isn't opening fully, then it isn't sealing the bypass port below it, which will exacerbate any overheating issues.
 

Big Bart

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Some other avenues you may want to look at. (Not suggesting you did not do all this.)

1) I would check your IP timing ASAP. There is a guy on e-bay selling what seems to be army surplus Tech Time unites for about $200. Once I replaced my injectors but did not have time to set the timing that day. Next day started having cooling issues only when towing. Turns out my timing was about 8 degrees off. (Guessing was a couple of degrees off but new injectors opening later added to the problem.) Be careful as some shops will say they will time your IDI but many on this site have reported there local shops simply do not have the tools (Or it broke and was not replaced.) so they time by ear. So maybe they get lucky and get it right or maybe you get burned with a problem.
2) Check your injectors and make sure they are the correct ones for your turbo. (Could be adding too much or too little diesel.)
3) You may want to replace that new thermostat for peace of mind. Never assume new parts work. A small percentage do not.
4) You mentioned 4th gear so guessing you have a manual. But for those who read this thread later and have a automatic, the radiator cools the tranny fluid, so a tranny with issues running hot can complicate a heating issue. A external tranny cooler can help out.
5) You mentioned the turbo is cooled by the coolant. You may want to inspect the turbo to insure it spins freely (Bearing are good.) and is not binding up and if oil lubricated the oil lines are not clogged. (Due to burnt oil inside the line.)
6) If your radiator is aluminum just double check it is not clogged or ballooned. Most have a good experience with these aftermarket radiators. You may want to test your radiator has a good flow. One member suggested draining the radiator, leaving the cap off, pulling the bottom hose, and holding your hand over the bottom radiator outlet. Filling the radiator with water and pulling you hand to see if the pours out as expected or is slowly pouring out suggesting a clogged radiator. Never tried it, but would if I was having issues. Also look at the fins, do they looked balloned? Very common the amature race circuit that folks over heat, balloon the core, and dimish the cooling effect. (The core tubes expand and smash each other and close up the ones next to them, causing a reduction in flow.)
7) Lastley and guessing you have, but if you do choose to go to 3rd gear and slow up does the problem go away, get worse, or stay the same? My truck is a is not turbo with a C6 so towing up big grades looks like 2nd, 2,500 rpm and 40-45 mph.

Let us know what you find to be your cause of the heating issues.
 

Cubey

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Thermostats are cheap. I know yours is new and motorcraft and all, but if you're leaning towards a faulty thermostat, throw another one in it.

Some food for thought. If the thermostat isn't opening fully, then it isn't sealing the bypass port below it, which will exacerbate any overheating issues.

Boil testing new thermostats isn't a bad idea. I did that with mine. It should open at around 195 and water boils at 212 so putting it in cold water and heating it up to boiling should make it visibly work if it's not faulty. Then take it out and let it air cool, it should close back.

You can always boil test your existing thermostat too if you suspect it's bad. If it is, you should be able to return it under warranty if it's within the time frame.
 

03wr250f

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He's running an air to air intercooler. You should skim through his build thread, it's really good Sunday reading lol. It made me jealous but he put a LOT of love into this truck, even re plated the fasteners![/QUOTE]

Thanks!

When I found out he had a comprehensive build thread,I went and checked it out. The tail end that I did read answered several of my questions. And i learned his build is incredibly similar to mine, which is helpful and cool to know of someone else out there who has done similar to myself.

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Jim993

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I am not sure of the load you are pulling and maybe I missed it, but the first thing I would take a very close look at is the radiator. Have a radiator shop take upper tank off, tubes all clear? If they are clear, a bigger radiator may be needed.

Last August I drove my '85 F250 4x4 C6 from CA up through Tehachapi, Kingman and on to Prescot with a ton in the bed, 109 degrees at Needles for the climb to Kingman and Prescott. I never saw coolant temperatures above 200, transmission above 230.
 
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