I was wondering how hot some of the highly bombed trucks were running & how long are they being ran at high temps. I can peg my pyro, if I stay at WOT for too long in 5th gear empty & 4th gear if loaded very heavy, I try not to make a habit of these high temps, but was wondering if brief hot runs are gonna cause any major longevity problems? thanks, Dusty

 

In short..yes. it better to not do that if at all possible and you wanna keep yor rig for a while<br><br>Don~

 

;D Of course you can keep it pegged at 1300 if you want to but its a good idea to keep it below 1200 if you want the engine to live a long life...I have only hit 1200 once pulling a loaded trailer up a mountain road and I was down to 5 mph by the time I hit the top of the road....if your EGT gauge has color coded temps it best not to run in the yellow very long and never hit the red zone

 

[quote author=Don M link=board=7;threadid=8149;start=0#78631 date=1039565424]<br>In short..yes. it better to not do that if at all possible and you wanna keep yor rig for a while<br><br>Don~<br>[/quote]I was racing a bombed 2001 Powerstroke over Burthod Pass I was pulling a 20ft Arctic Fox 7500lbs and he was pulling a 15ft Fleetwood about 4800lbs, altitude about 11500 feet I think and very steep. I actually passed him going up the steepest part and my egt's did hit about 1475 deg, but now I am wondering at what cost, I was only at that temp for about 30 seconds or so. but my friend for over 10 years and a Ford fanatic for life, I WAS NOT GOING TO LET HIM BEAT ME OVER THE PASS, it was Ford against Dodge and I had to prove who had the stronger truck &quot;ME&quot;..Anyway, do you guy's think I caused any damage to my truck running at that temp?

 

Can a stock truck produce dangerous EGT's? I do not have a gauge yet, so I have no way of keeping up with the temps. I pull a 20 ft. stock trailer in the Blue Ridge mountains, so I see plenty of hills and grades. Thanks guys!

 

&lt;---over 2,000 degrees {pre-turbo} for 2 minutes solid..cracked ears off head...and cylinder wall damage :'(...1350?what is the problem?

 

[quote author=JC Webb link=board=7;threadid=8149;start=0#78769 date=1039576793]<br>Can a stock truck produce dangerous EGT's? I do not have a gauge yet, so I have no way of keeping up with the temps. I pull a 20 ft. stock trailer in the Blue Ridge mountains, so I see plenty of hills and grades. Thanks guys!<br>[/quote]Hello J.C, When my truck was stock, I was pulling a 20ft. trailer through the Rockies and I push my truck pretty hard, it took alot even at high altitudes to get it over 1100 deg. You don't have anything to worry about with your truck. Mike

 

Aluminum begins to melt @ 1650 degrees, <br>BEGINS is the key word!<br>Danny

 

I read all this stuff on EGT and find it very interesting because I want to do some slight modifications and pull a heavy load. I see all this talk of high temperatures but never anything about ways to lower that temperature. It just seems with all these high HP products out thier their must be ways to cool them down, seems a better intercooler would just be common sence? So is there anything out thier?

 

Anytime and engine is pushed beyond its design limits it takes some life away.<br><br>When I had the stock HY35 turbo and dyno'd at 388 HP I could peg 1500 in the 1/4 mile. Its scary to look up and see the needle quiver on the peg.

 

Some things that will help lower EGT's: helping air in, and freeing up the exhaust out. Better filter like a BHAF, getting cool outside air to the filter, more efficient intercooler, bigger exhaust, removing muffler, different turbos/housings, also advanced timing.<br><br>The most dramatic drop in my EGT's when towing heavy came from advancing the timing.

 

This is where old truckers have the best understanding of what is right, the Pyrometer-Manifold Pressure-Water Temperature guages are your best friends. Co-ordinating an understanding between those guages and your right foot are essential in a mechanical injected engine while in a over fuel condition. On big rigs the pyro is always post turbo so any numbers you see in excess of 1250 degrees for more than 10-15 seconds creates the possibility of nuclear melt down scenario-Back Out of it! Traditionally Cummins dont like Water temperatures in excess of 210 degrees sustained for more than 2-3 minutes (fan stat cycle time) Back Out of it! Manifold pressure (boost) is directly relative to HP and air input, with mechanical injection when you see excessive black smoke while under continous high load (6000lbs+ on a hill) gradually back off throttle until smoke basically diminishes while maintaining the highest possible manifold pressure. If for some reason any or all three conditions can not be controlled, gear down and Back Out of it. Driving accordingly will give you high performance when you need it and an understanding of when to give in. When reading through posts you will discover situations of failure and those that caused it will generally say they should have Backed Out of it. Electronic Engines are in stock form unable to over fuel as precautionary programming is built in including the dreaded emergency defueling mode. When you start messing around with high performance parts and modifications go back to what I wrote on mechanical over fueling conditions, right foot must function within the realities of engine distruction. Drove many miles with my 91 jacked open/timing advanced without all these mods as they were not available yet, put a lot of miles on the old 380 Cat 3406 jacked and kicked lots of 444XT Cummins all over the hills tuned with a little timing and an allen Wrench. Those guages are what is important along with your attention, swallowing your pride and not being first guy up the hill may be easier to swallow than $5000-30,000 in repair bills and no truck. Cubic Horse Power= Cubic Dollars- how fast do you want to go, Truck Driver rule #1- dont walk if you can drive, dont cause anything to create this situation. PK

 

guys, melting pistons isn't the problem. the problem is allowing them to get too big (expansion via heat) way before they start to melt. There is a large temperature drop from piston to exhaust manifold, and yet another large temperature drop from exhaust manifold to post-turbo downpipe. The best possible way to keep the pistons properly sized is to keep exhaust manifold temperature below the Cummins spec of 1250 degrees. Anything higher than that and you are staring risk in the face.<br><br>Stock trucks are so hamstrung in terms of power that they are not really capable of acheiving dangerous EGTs. otherwise, DC wouldn't be able to warranty these trucks used for the pulling applications described in the manual. You do need to watch turbo cool-down though, again according to the manual, which is very clear on the subject. <br><br>Dusty-- pegging your pyro ? yikes! you're supposed to actually take action in response to the readings you get ;D.

 

Doug is right about the cool down but it is different from running EGT's. When you shut down your engine there is NO cool clean oil running through the turbo bearing area therefore all the heat in the housings will soak into surrounding metal (impeller shaft and bearings). This process is called coking and basically thats what it does is coke the oil and transform it into a hard carbon substance which effectively siezes the turbo impeller shaft. If it becomes siezed when stopped it just cost you a turbo, if only partially siezed and it piles up under load driving they usually break a shaft with interesting results. Had one on a 3406B/425HP that went through hood on a Pete, engine was jacked and the driver drove it like he stole it. After he left our employ and we payed what was owed by law the truck got fixed- $18000.00 CDN. PK