How hot is too hot

[onetonjohn]

Driving my 86 F350 today to get some propane tanks re-certifiied. It's pretty hot - maybe 90. Driving up hill (this is C6 truck) were going slow, and temps rising. I remember the fan clutch used to kick in around 210 - then it would sound like a jet engine. Today... Nothing. Temp went all the way up to 220. Still nothing. They were short hills and temp would come back down when I got off the gas, but curious if fan clutch is busted, or if this is normal. How close am I to the edge at 220F?

 

[DirtyWood]

I've read plenty of reports of people maintaining 230F and being fine but I've also read once you hit 245F the engine might be cooked. I once had the factory overtemp light come on briefly and the engine was okay. I could be wrong here but I thought I read the fan clutch wasn't supposed to kick in until about 230F.

 

[IDIBRONCO]

At 220* you're just fine.

 

[Black dawg]

Dont know what it would take to ruin one, especially if it doesnt lose coolant.

Have seen 265-270 (on real temp gauge, and verified with temp gun because I didnt believe it) for 10 minutes or so several times. This was pulling a pass several times over a couple summers.

 

[hacked89]

I run 285, real temp gauge, 15-20 minutes at a time. Motor runs perfect. Was fresh build and it was right on spec so doesn’t have much room to breath. Some piston wall scoring but nothing slowing it down.

I also run double oil coolers

 

[03wr250f]

Dont know what it would take to ruin one, especially if it doesnt lose coolant.

Have seen 265-270 (on real temp gauge, and verified with temp gun because I didnt believe it) for 10 minutes or so several times. This was pulling a pass several times over a couple summers.

the heck were you doing?
and for sure you have something wrong with your rig, likely a fan clutch


as for the op, 220* is not outside the realm of normal, however if you arent hearing the fan clutch lock at 220* i would absolutely suspect a bad fan clutch.
i would replace it and retest

@hacked89
what do you have for double oil coolers? what is your setup? 285* is absolutely insane
why are you ok running that hot, there is absolutely no reason, need or such that you should be running that hot.
oil temp will probably be 300* at that point and the rate at which even modern oil degraded at that temp is astounding.

With my upgraded fan and clutch i have yet to get it over 220* coolant and 225* oil temp when trying to get it hot climbing the Continental divide with a small trailer on, in 90* ambient temp.
or with 13k behind me and water **** on, However some of my customers have been able to hit 235* with my fan and a good working fan clutch, but that was also a 12.5k lb fifth wheel up a 6% grade in Arizona in the summer ...

 

[asmith]

I believe @hacked89 is running without a radiator in a demolition derby.

 

[03wr250f]

I believe @hacked89 is running without a radiator in a demolition derby.

ah ok that would make total and complete sense

a customer of mine does the same thing, looped cooling system, no radiator, 27 psi rad cap, and my fan for air cooling purposes, apparently it still does a great job of pushing sir over the motor so much so it actually does some air cooling

 

[Nero]

Just make sure your rad cap is in good shape. They sell cheap testers, if your cap is bleeding down it'll want to boil sooner. For each psi of pressure the boiling point gets raised by 3 degrees. So with a stock 7psi cap your boiling point is 233FF
Some of us like me run a 13lb cap, raising it to 251F to allow for some progressive cap failure.

 

[Black dawg]

the heck were you doing?
and for sure you have something wrong with your rig, likely a fan clutch

Nothing wrong, everything functioning as new, except much more power than stock, and with an intercooler in front adding more heat to the radiator and reducing airflow to the radiator.

I have owned enough and used enough of these trucks to know that with power level much over factory turbo level, 7.3 idi motors will run very warm being worked hard.....have never been able to run anywhere near max power for for very long before temps start climbing quickly

I would like to try one of your fans, are you back in mt?

 

[franklin2]

Just make sure your rad cap is in good shape. They sell cheap testers, if your cap is bleeding down it'll want to boil sooner. For each psi of pressure the boiling point gets raised by 3 degrees. So with a stock 7psi cap your boiling point is 233FF
Some of us like me run a 13lb cap, raising it to 251F to allow for some progressive cap failure.

I do not think 7 psi is stock. I have run 7 psi on a old radiator I was nursing along. But 13 psi sounds more like the stock pressure. And you can go on up to 16 psi if your radiator is in good shape.

 

[Clb]

03 wr 250
Hot link for your fans out there somewhere?
I remember something like
Blue dot
An oil swap
Spring retension
Mine is probably due for some P.M.

 

[Nero]

I gotcha

Workhorse Customs

Workhorse Customs. 5,140 likes · 45 talking about this. Upgrading Old Trucks

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[hacked89]

ah ok that would make total and complete sense

a customer of mine does the same thing, looped cooling system, no radiator, 27 psi rad cap, and my fan for air cooling purposes, apparently it still does a great job of pushing sir over the motor so much so it actually does some air cooling

A A - one in the same lol

 

[david85]

I gotcha

Workhorse Customs

Workhorse Customs. 5,140 likes · 45 talking about this. Upgrading Old Trucks

www.facebook.com

I recently ordered mine. Just waiting for the second parcel to arrive with the upgraded fan. Already have the electric fan clutch and hardware in my shop waiting to go.