I was reading on the internet today that someone has hit 1500 degrees post turbo a few times with no problems. Was i too quick at throwing the b.s. flag, or is this possible? also, what is the difference in temps between pre and post turbo egt setups?

 

Things can get REALLY hot! I've hit 1800 pre turbo and thats where it stopped because it pegged. I wasn't paying attencion. oops. 1500 post turbo is really hot though. I'm not even sure what pre turbo was. But I'm sure the turbo wasn't liking life too much!

 

That's no problem if you hit it occasionally.
I think Cummins says the maximum SUSTAINED temp should not exceed 1250 deg or something like that.

 

i thought the sustained temp was 1350? i dunno tho its been a while. lol


back in the day when i had a hot truck, i was pegging my pyro for several seconds. With no problems....yet lol

 

yeah, but 1500 post turbo? i guess maybe i was wrong

 

1500 post turbo wouldn't be impossible if all you added was fuel and tried to squeeze it through the stock turbo..

Either way, you take your chances. High EGT's do more damage to other components like head gaskets, valves, seats, injector tips, piston crown edges, rings and cylinders than most realize. I have hit 1400°F lots and its only for a few short bursts. But holding it there for any period of time or hitting the 1600-1800 mark is playing with your wallet. Sooner or later you will be bringing it out to the table.

 

1500* post turbo is from 1800-2000* pre turbo...depending on load. That's hot but doable.

It's not how hot you get...it's how long you stay hot!

RJ

 

You, and myself included, do not want to know how hot my EGT's have been. I guess if it stops at 1600* itis only 1600*, right? Even if it takes 3 (yes three full) seconds to come off 1600*, right?

 

I feel your pain!

 

turn it off right away when it gets hot like that

 

I hope you don't mean turn off the engine. If you do well, go right ahead, I aint gonna follow. It's much easier on a diesel to let itse;f cool down by running than just shuting it off.

 

Wow- notice anything glowing orange under the hood?

Would the head cracking/warping be an issue with egts like this even if the pistons survive?

 

I would have to say that, due to the decompression across the turbo, the temp should decrease rather significantly. I know that in jet turbine engines the temp will drop a hundred or two degrees C in a short distance across a turbine or two.
In a piston engine, why would anyone care about post turbo temp anyhow? Once the air is past the turbo, there's nothing to destroy. I would want to what the air temp coming immediately out of the head is, no? I am looking to put a pyro in in the near future and I have a manifold that is tapped. Seems logical to put the thermocouple here..

 

Definitely put the pyro pre turbo.

Some people are a little over cautious about egts. They think if it hits 1600 that its immediate engine melt down. While its good to keep the engine as cool as possible, its not going to hurt the motor much if you have short bursts with high temps. Ive pegged my 1600* pyro more times than i care to count, and can shoot about a 6 inch flame out of my stack. The truck is tore down right now for ported/oringed head and camshaft install. The motor has 230,000 miles on it and the pistons/cylinder walls look great. Cross hatches are easily seen and the pistons/valves look brand new. Long live the cummins

 

You will pay the price for repeated trips to 1800+,esp on the 24V's,when you remove the head to replace the gasket you will blow,you will find the head cracked ,and in need of replacement.Also a lot of the heat runs up the valve stems,and tranfers to whatever it can,it ruins valve seals,guys wonder why there trucks smoke more after,also weakens valve springs when they get too hot. If your getting that hot you need to back off the fuel unti lyou get enough air for it--or pay the price.