I'm now leaving on Friday at noon and been meaning to ask this question for weeks now. Heard a lot of talk on here about EGTs. I've only towed 80 miles round trip twice last year. I've got a 2 hour trip all highway and some hills in middle Ohio. Rt 77. I heard that you can drive at 1100* all day but when you cross that threshold of 1200* your in trouble range. So my question is how long before your engine is toast? I've only seen it once on my truck towing and once recently test driving after some repairs.

 

I can't answer your question, but I can guess some of the additional info you'll be asked for. How much weight are you pulling? How fast are you pulling it? What gear/rpm are you pulling in/at? Good luck, I'm sure some of the tow pigs will be along to help soon enough.

 

Oink!

In My Opinion!

You can run 1250*F all day. Brief 30 second bursts up to 1400* are OK as long as EGTs cool afterwards. Sustained 1300* plus is dangerous.

You need tactics to control EGTs. Keep the revs up! This flows more air thru the engine and provides cooling. Click off the OD when encountering a grade, and if the EGTs get bad select the next gear down. If that slows you down that's OK, don't let your ego roast your engine.

Worst case scenario is low RPM and max fuel, don't do that.

 

Is your pyrometer in the manifold?

 

Pyrometer is in the driver side manifold. Camper 10k max. 4;10 rear end. As far as speed it's 55 to 70 there. I plan to run about 60 at max.

 

What part of OH you from? I’m a neighbor across the river. Still looking for a crazy 7.3 friend near my location.

Excuse me if I’ve already asked this question.

You’ve done the KC Balanced Assembly correct? (Time to add a signature )
4.10’s and the KC internals should tow well with everything sealed up good. My opinion anyhow.

 

1200-1300 I'm OK with, but I have an alarm set at 1300 to bring my attention to it so I can adjust my driving (Edge controller, probe drilled into in left manifold).

Of course, on the flats cruising (10k enclosed auto, or RV, trailer) I expect to see 800s most of the time.

Geneally speaking, if I'm not visibly "rolling coal" - not even a little bit visible wisp of smoke in the right rearview mirror - then my EGTs are good. I tried a high-hp tune once on a lark (DP Tuner, I only use the Edge for gauges) and once the visible smoke started EGT slammed over 1400, heading toward 1500, in a couple seconds. Nope nope nopity nope for me.

I asked on this topic a couple years ago and never got a solid answer; has anyone done any solid testing? Are there guidance from Ford? I'm curious about what EGTs start causing castings to soften and maybe valve seats to start sinking, and how long it takes. 'Til then I'm happy with my current baselines.

 

No tuner at lease not yet. Wanted to get the truck running the best at factory standards first and see how it pulls my camper. The truck is a tool for me and I like to take care of them. Anyway I did see about 600 to 800 EGTs on flat ground. It's mostly flat ground here. Boring roads especially for a sports car guy. Where I'm going today it's starts to get a little more hilly and that was my concern was a long grade up hill. I know I'm going to hit those EGTs today and wanted to mostly know how long (time) can we get away with over 1200?

 

This is my record so far. I wouldnt make this a repeatable temp pattern though, nor hold it more then 15-20seconds lol

 

This happens on every hill. 7.3, ZF6, 4.88 rear axle F550. Let 'er rip!!

 

Might I suggest that with a stock PCM/tune you shouldn't have any concerns?

Ford should have tuned this to cover even the worst leadfoot idiots (stock tune sure feels that way...once you tune, you'll never go back to stock.)

 

Exactly.

But 1250* all day long if you wanted.

 

Years ago before going down the mod rabbit hole I did 1250 cross country for days on end. At that temp tho you're fighting heat soak more than anything. Keeping the cooling fan off will help gain 2 mpg.

 

[$6.50 diesel part-of-brain takes notice...and begins to derail topic...]

Can you elaborate? I had an oil temp prob that turned out to be a water temp prob that turned out to be a bum radiator fan clutch. Upon replacing said clutch with a "heavy duty" version I noticed an immediate decline in fule mileage while towing (and a noticeable increase in fan noise which doesn't really bother me except for the fact it's an audible reminder of how much fuel it's sucking up...)

 

So way back before FTE when I was towing our 5th wheel out to Cali and back to OK, the cooling fan would be on every time there was a hint of incline. Oil temp would be around 225. Once I'd had enough and went full hog with tow mods as the cooling fan ran less mpg would go up. If I ran hotter tunes that resulted in the fan running more mpg would drop. It got to the point where I could guess within almost a teth of a mpg what the mileage would calculate out to be at fill ups based on how long the cooling fan ran for that tank.

Now that EGTs haven't been a concern for 3 years and I had the truck towing awesome the fan rarely comes on at all, even in hot tunes.

Remove the grill and take a comb to your condenser, or the transmission cooler, whatever you auto guys have in the very front of the truck and clean out all the sand pebbles and straighten your cooling fins from bug and bird strikes, then spray a degreaser in there and rinse it a few times. Doing a good thorough straightening and degreasing will take a good 2-3 hours. That will help bring down your cooling system temps some as well as decrease the cooling fan engagement. After that mods of some kinds will be needed to bring down EGTs and help lower the under hood temps to keep the fan off

When you consider that the fan uses 25-30hp to run that's around 10% of your stock peak HP, if you are applying that power to the road instead of the fan your milage will be more vs using it to move air