ET Help

[ERIC668]

Just put my new parts on and I can get some pretty high ET's. My question is what does Cummins say is the max temp and what happens if you exceed it . Will it damage the engine it say it goes over by a just a little for just a few seconds ? Or does it take a few min. to damage it? Any help is greatly appreciated.

 

[Gary C]

What are your EGT's????



I have seen 1700 on mine doing burnout's but just for a second.



One or 2 seconds is fine but for a minute, you better be careful.



Towing up a hill you should go over 1300 degree's some people say.

 

[ERIC668]

Unloaded on power level 5 and Wide open throttle 0-90 mph I can hit 1300 to almost 1400 if I keep my foot in it. But if it does exceed 1300 It Is not for more than a few seconds.

 

[Gary C]

Me personally, I would not sweat it. JMO



Maybe someone can chime in.

 

[KatDiesel]

Your fine.



1400° for a few seconds... ... . one can only dream WHen I have everything on and in "warp drive" I can get 1600° easy, but its never for more the 14 seconds

 

[bbutler]

1300 1350 max, after that your on your own!!!

 

[WAYNE]

I heard 1600 F keeps the top of the piston's clean.

 

[chuck3]

I bet it would.

 

[CTabor]

Keep it at 1600* and you will have pistons so clean that you will be able to see right through them.

 

[kswieringa]

PRE or Post Turbo

I'm installing a pyro . If I go pre turbo how do I know if the turbo has cooled enough before shutdown?

 

[MikeR]

A guy that's popular for building high hp diesels among this board once told me it takes 36 seconds to melt a piston at about 1800 degrees. So he said just don't hold it there quite that long.



kswieringa,

Anything under 350 deg is fine for shutdown,so with a pre mounted pyro,if you wait until it gets below 300 or even to 250 then it would have idled for a long enough time to let the turbo cool.

For the 'pre' vs 'post' argument; I feel it is more important knowing how much heat is going into your turbo rather than guessing how much heat just went through it.

 

[Boost]

Is the problem with high egt's that the tops of the pistons melt or is it that the pistons expand to the point that they start scaring the cylinder walls? Or is it both?

 

[Strick-9]

I've been bombed heavily for over a year now.



EGT's to 1500° regularly, but never more than 5-6 seconds at a time. Usually it's more like 1-2 seconds.



I've probably been to 1700° a few times.



I've pulled at 1250- 1300 for several miles.



I pulled my head off 5 weeks ago and it had 4 or 5 cracks in it.



All cracks were small (i. e. 1/2" or less). None were through.

Head shop said it was fine to reassemble with. They see that all the time.



High temps cause head cracks before they melt pistons.



-Chris

 

[Roger rodbolt]

Paper clips and egt's

A Cummins instructor compared high egt's and pistons problems to bending a paper clip. You may bend it for a while, maybe further and further but when it breaks you can't put it back together



MikeR,



Idle cooling the turbo is accepted practice here on the forum and I do the same. However I've never seen the 350 degrees post turbo published by Cummins or Holset. Of course I haven't really looked either but I was talking to another turbo manufacturer at the Oshkosh airshow and they said that on our diesels just spooldown time should be enough... ... I'm not promoting such but thought that you may have the Holset info?? Thanks,

 

[jwdeeming]

On the turbo shutdown temp, I was told the following by a diesel mechanic: Since engine oil is pumped through the turbo, and since oil burns at 400 deg, you want to shut down comfortably under that, otherwise you potentially burn or at least ruin uncirculating oil sitting in the turbo. I have an ISS Pro turbo temp monitor, running off a pre-turbo probe, and it shuts off at 300 degrees. In normal driving conditions, my truck idles down to 300 in 15 seconds or less. I've never seen it take more than 60 seconds.



JimD