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210 hot or NOT?

I think the answer here is that we are educated & watching the temps so we adjust our right foot & or gearing to manage the deficiencies. I doubt running at 210 would kill anything & certainly not if the motor peaks at 225ish & then we compensate to get it back down to 200ish.

IMO like has been stated in this post already what is more likely to kill our beloved 6.5 would be the none educated blind consumer that put his faith in the GM gauges / hot indication & ran the motor with the go pedal to the floor until it hit 260+ range. Dam shame something so simple was not addressed by GM but in there defense this motor was ever intended to pull 20K, still does not change the absurdity of 260 hot placement on the gauge.
 
I will also point out that I think 210* isn't a problem, my northstar [eldorado] runs at 200* min. The northstar is an all aluminun engine that sheds heat faster than a cast iron block and heads and cast iron block and aluminum heads.

This temp of 200* min is done for atleast two reasons. 1. lower emissions [EPA] 2. higher mileage through better fuel atomization.

A diesel engine is also in the same category of wanting /needing some heat to help atomize fuel for better power and economy.

Running 3 hours each way to Myrtle beach I was at 220/230 the whole way, and filled up my tank yesterday and found that I avg.17 mpg. towing 5000lbs.

I believe the detroit block isn't capable of this due to design flaws and the combo of high mileage that are on them now.

I did this all by mistake and couldn't pull over to mod the F/C because the engine bay was to hot and the family would have melted witout the ac on. Well it did fine so I left it unmodded and drove it home running at the same temps 220*/230* with no problem.

Would I run this temp all the time now? Sure especially if I had head studs, I also want to point out that my egts were always below 1000*. That also is probably key to why it lives, higher sustained egts would probably have killed it.
 
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Agreed there is also the distinct probability that the older lower flow water pumps were allowing the rear cylinders to operate at dangerously high temps that were not displayed accurately due to the lack of flow and the placement of the probe...point being 220 on a high flow 130gpm pump setup may tolerate this way better then the older low flow stock OEM pump.
 
I may put a coolant sensor in the rear of the head to compare the temp differential from front to rear. And if differential is greater than 10/20 percent I may fab up something to allieviate that.

Either way I would like to see the difference from front to rear temps.
 
You guys are onto it, now ... Bill told me the story of how the 'balance-flow' came to be, and it was by putting sensors all over the engine and looking at the large variances. Those back 2 cylinders on the passenger side were WAY hotter than the rest of the block; Bill figured the differential stresses were what caused the cracks.

The balance-flow concept did a lot to equalize the temperatures... what the new thinking is with the restricted crossover and high-flow pump does the same. Add a re-calibrated clutch, spotless cooling stack, dmax fan, the right Tstat, and locking the TCC when pulling, and you should be fine.

I've said it before; there is no silver bullet to cooling under load - you gotta do a lot of little things right and let them add up.
 
A diesel runs best at around 200 ect on a cold winters day for sure. I drove dumptrailers for years and in the heat of summer it always felt like the truck was losing a little power where as in winter when the truck was at operating temp but the air outside was nice and cold, you could feel the difference.
 
Acesneights1 said:
A diesel runs best at around 200 ect on a cold winters day for sure. I drove dumptrailers for years and in the heat of summer it always felt like the truck was losing a little power where as in winter when the truck was at operating temp but the air outside was nice and cold, you could feel the difference.
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That's also the issue with SSD's 'cold air intake'...( LOL ) ... the incoming cold air in the wintertime makes a huge difference. Lots more oxygen in the same volume of dense air means you can feed it more fuel.
 
Ok I looked that up but how do I tell my truck to do that when I am towing? Isnt that what happens when u kick it into passing gear or when u pull out towing in OD it is in 1st then shifts to second then shifts to 3rd and then shifts to fourth but when u let off the accelerator it drops RPMS and goes into another gear or I assume out of TCC lockup? How would u keep it in that gear or lockup or is my tranny adjusted wrong, I set the TPS myself cause it was wrong when I got the truck.
 
Ok thanks Crank I think this is worth learning. I am sure somebody will help us out. In the meantime I am gonna look it up if I can.
 
Almost every gas powered vehicle that comes into our shop runs at 210 degrees. Also in the early 90's GM small cars ,the electric fans would not come on until 220 degrees. My friends 04 Dodge Cummins diesel also runs at 210 .
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Most vehicles have the ect gauge set at 12 o'clock or straight up when at normal operating tempurature.

Maybe that is where it is supposed to run, just under or straight up. Remember they do come with a 195* t-stat which is only 15* away from 210 not a huge difference in temps.

I believe that with age and the amount we overwork them from what they were intended for is where the problems come in. DI engines these are not.

An engine in good health and well maintained will take 220/225 all day long.
 
robzombie4551 said:
I may put a coolant sensor in the rear of the head to compare the temp differential from front to rear. And if differential is greater than 10/20 percent I may fab up something to allieviate that.

Either way I would like to see the difference from front to rear temps.
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I have the 2000 balanced flow pump, Heaths fan clutch, and 02 DMax fan. I put my add-on temp gauge sender in the block-off plate on the rear of the pass head. Under normal DD driving it takes a long time to come up to match the stock gauge. It eventually comes up close to the stock gauge.

We just towed Hy 26 over the Coast Range for the first time. It has two passes in the 1200-1300ft area (according to the map, but it seems like we went over three passes). On the first one the stock temp gauge went up to the second line past 210* for a short time. The extra gauge went up to just over 220*, however I wasn't watching it as close as the stock gauge. After topping the hill the stock gauge came back down within a couple minutes or so. The extra gauge took a lot longer to come back down. I have seen this same delayed action before.

We will be leaving this afternoon for another tow. This time no hills to go over though, and only about 40 miles instead of 150 miles. I'll try to pay closer attention to the differential between the gauges this time.

Don
 
Got back this afternoon.

We live just over 1 mile from the freeway (country roads) so when we leave the house with a cold motor the temps haven't gone up very much when arriving at the freeway. I was trying to stay right at 60 mph for the whole trip. Within about 3 miles from the freeway entrance the add-on gauge had balanced to the stock gauge. Obviously the quicker balancing of temps was due to towing the trailer. The temps were at, or just over 195* on both gauges. The elevation went up by only about 300ft in 40 miles. The biggest "hill" was an overpass over railroad tracks on the freeway. There is more up and down in the road after leaving the freeway, but it is all so gradual.

Don
 
So what you're saying is that you have minimal differential from front to rear , but did you at any time maintain high load/1000* egt for any length of time?

I'm trying to find out if under sustained high load/egt, can the coolant system keep a sustained balance or if the back two cylinders retain more heat and therefore would need further modifications.
 
For this trip there was minimal difference. BUT, this was a very easy tow so I'm not able to give you any more info than what I've already given. As previously noted, under normal DD driving it does take a while to get the rear of the pass head up to same temps as the stock gauge. I'll be DDing about 15 miles later this morning so I'll try to remember to watch for how soon the temps balance out.

Don't forget that I do have the balanced flow pump. I don't have any info about what things were like pre-balanced flow pump as I didn't have the extra gauge then. It's less than a year since I installed the balanced flow pump so my only other trip was last fall for hunting and I don't clearly remember what the temps or EGTs were, just that they were good.

On this trip the only time EGTs hit 1000* or slightly over was accelerating upon entering the freeway and accelerating to speed when I left the freeway and went unto Hy 34. These times were very short.

Later this month we'll be going to a church family campout and I may be able to give you more info then. The trip will be to Silver Falls State Park so mostly on back country roads. The first part is mostly flat country roads with normal corners and straight areas. The last probably 20 miles will be much more crooked and hilly with several chances for more extended EGT observations. I'll try to remember to keep detailed info on the trip.

Don
 
handcannon said:
I'll be DDing about 15 miles later this morning so I'll try to remember to watch for how soon the temps balance out.

Don
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I remembered!!

9:45 AM-- ambient temps, 67*. It took about 3 miles to get stock gauge temps up to 195*, aux gauge wasn't even close.

About the 7 mile (had been traveling at 60-65 mph) area left the freeway and went to Hy 20, the aux gauge was hovering around 170-175*. Arrived at destination at about 15 miles, aux gauge was still around 170-175*.

1:30 PM--left on return trip, Hy 20 to Albany (8 miles) ambient temps, 84*. Aux gauge went up to 180-185* within 3 miles. Stock gauge was above 195*, maybe close to 200*. Spent some time running errands in town. In stop and go traffic the aux gauge went up to around 190*, stock was at a solid 200*.

4:30 PM--left town to go home, ambient temps, 87*. At 60-65 mph on the freeway the stock gauge was between 195 and 200*, aux was at about 185*. DDing and hwy speeds seems to help keep a 10-15* difference between stock and aux gauges.

This was a short distance check on temps so a longer distance may show up with a closer spread of temps. Towing works the motor more and seems to keep the aux gauge temps up equal to the stock gauge. I'll try to remember to give an update at the end of the month on how towing in a tougher situation effects the temps and EGTs..

Don
 
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