EGT-Values for a Turbodiesel.. (1 Viewer)

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But your engiens are stock with a turbo? I think in that case it's less critical anyhow, you should have the piston-cooling etc.
 
EGT at cruising speed is not an indicator that's useful. To many variables.

It's peak EGT under high load, heavy throttle you need to work with to tune to the upper limit of what you're comfortable with.
If your cruising 65mph @ 1250F I would say that is useful to know .. right ? Or am I missing something
 
If your cruising 65mph @ 1250F I would say that is useful to know .. right ? Or am I missing something

Sure. It's about as useful as looking at the factory temperature gauge, and seeing that it's not in the red.

So cruising is driving along the interstate, keeping a steady pace, part throttle, nothing particularly noteworthy.
If you need to watch your EGTs in this scenario, you have issues that should be addressed. You should be able to enjoy the scenery.

EGTs are gonna max out when you're at full throttle, in a high load situation, not cruising.

example being: loaded with camping gear, pushing hard up a mountain pass, holding top gear, right foot planted on the floor. RPM slowly dropping. You're dumping maximum fuel into the engine. The engine and turbo can't deliver any more air. AFR goes up. Combustion heat increases. Heart soak in the engine, turbo exhaust goes up.
This is when EGTs matter.

Tuning the fuel settings so your peak EGTs don't/can't exceed a safe level means you can ignore the EGT gauge until you are pushing hard under load.
Learn to be sympathetic to your engine.
Down shift when you're full throttle and losing RPM.
Your diesel is happier at higher RPM in a lower gear, at part throttle, rather than struggling to hold ground in a high gear with your foot to the floor. Then monitoring EGTs at these times is just checking that conditions aren't pushing the heart in the engine beyond the parameters you've set.

Short bursts of high EGTs were acceptable to me such as passing a slower rig on a hill. Pushing it into high EGTs for 30, 60, 90 seconds to get past that car before the passing lane ends etc I had no issue with.
I tuned so that 1dawhen pushed hard in normal driving I saw EGTs higher than most, and only if really pushing hard they would cross into a range I was not comfortable seeing as a sustained condition. That's when you watch EGTs
 
Sure. It's about as useful as looking at the factory temperature gauge, and seeing that it's not in the red.

So cruising is driving along the interstate, keeping a steady pace, part throttle, nothing particularly noteworthy.
If you need to watch your EGTs in this scenario, you have issues that should be addressed. You should be able to enjoy the scenery.

EGTs are gonna max out when you're at full throttle, in a high load situation, not cruising.

example being: loaded with camping gear, pushing hard up a mountain pass, holding top gear, right foot planted on the floor. RPM slowly dropping. You're dumping maximum fuel into the engine. The engine and turbo can't deliver any more air. AFR goes up. Combustion heat increases. Heart soak in the engine, turbo exhaust goes up.
This is when EGTs matter.

Tuning the fuel settings so your peak EGTs don't/can't exceed a safe level means you can ignore the EGT gauge until you are pushing hard under load.
Learn to be sympathetic to your engine.
Down shift when you're full throttle and losing RPM.
Your diesel is happier at higher RPM in a lower gear, at part throttle, rather than struggling to hold ground in a high gear with your foot to the floor. Then monitoring EGTs at these times is just checking that conditions aren't pushing the heart in the engine beyond the parameters you've set.

Short bursts of high EGTs were acceptable to me such as passing a slower rig on a hill. Pushing it into high EGTs for 30, 60, 90 seconds to get past that car before the passing lane ends etc I had no issue with.
I tuned so that 1dawhen pushed hard in normal driving I saw EGTs higher than most, and only if really pushing hard they would cross into a range I was not comfortable seeing as a sustained condition. That's when you watch EGTs
What do you consider to be sustained high EGTs ? I personally hate going past 1200 at all, but sometimes with a headwind with a slight grade I’m pushing 11-1200 sustained and I hate it .
 
1200f is about 650C? You won't hurt a direct injection diesel running it all day at 650C

My 1HDT saw 900C pre turbo messing around on the dyno and no damage at all evident. I'd see no issue with 800C for short bursts
 
What do you consider to be sustained high EGTs ? I personally hate going past 1200 at all, but sometimes with a headwind with a slight grade I’m pushing 11-1200 sustained and I hate it .

I know nothing about your engine set up. What engine? EGT probe preturbo?


When I had my hdj81, 750⁰c preturbo was widely considered the safe maximum EGT temp.

I personally think that's conservative.
I tuned so I'd see 750⁰c regularly in normal everyday driving (eg, passing traffic at 70mph uphill on motorway). My tuning limited EGTs to about 800⁰c UNLESS, I really pushed things, like holding a high gear, foot to the floor to pass before the crest of a hill.
Then, make a judgement. If you've been caught behind a truck with no passing lanes, you've got a chance to get passed, but can see there's only 2-300 hundred metres left before passing lane closes, and holding it flat stick well get you there, is it worth pushing it? Or do you back off and wait?
In these cases, I was ok seeing 900⁰c for short spurts.

I ran mine daily life this for about 2 years. I had the engine apart after blowing a turbo, and there was no sign of heat being a problem at all
 
I’m running a 4BT Cummins turbo diesel , Cummins rates these motors safety @ 1250F . I would assume that’s pre turbo (that’s where my turbo is )
 
@mudgudgeon what caused the turbo failure? I'd like to keep mine from failing...
Bearing wear. And boosting the stock turbo beyond its limits.
Impeller contacted the compressor housing and absolutely disintegrated.
Quite literally heard it POP! then smoke everywhere.

I had a replacement ready to go in, just hadn't found the time. Doh!
 
Sure. It's about as useful as looking at the factory temperature gauge, and seeing that it's not in the red.

So cruising is driving along the interstate, keeping a steady pace, part throttle, nothing particularly noteworthy.
If you need to watch your EGTs in this scenario, you have issues that should be addressed. You should be able to enjoy the scenery.

EGTs are gonna max out when you're at full throttle, in a high load situation, not cruising.

example being: loaded with camping gear, pushing hard up a mountain pass, holding top gear, right foot planted on the floor. RPM slowly dropping. You're dumping maximum fuel into the engine. The engine and turbo can't deliver any more air. AFR goes up. Combustion heat increases. Heart soak in the engine, turbo exhaust goes up.
This is when EGTs matter.

Tuning the fuel settings so your peak EGTs don't/can't exceed a safe level means you can ignore the EGT gauge until you are pushing hard under load.
Learn to be sympathetic to your engine.
Down shift when you're full throttle and losing RPM.
Your diesel is happier at higher RPM in a lower gear, at part throttle, rather than struggling to hold ground in a high gear with your foot to the floor. Then monitoring EGTs at these times is just checking that conditions aren't pushing the heart in the engine beyond the parameters you've set.

Short bursts of high EGTs were acceptable to me such as passing a slower rig on a hill. Pushing it into high EGTs for 30, 60, 90 seconds to get past that car before the passing lane ends etc I had no issue with.
I tuned so that 1dawhen pushed hard in normal driving I saw EGTs higher than most, and only if really pushing hard they would cross into a range I was not comfortable seeing as a sustained condition. That's when you watch EGTs
Thank you for this, a very comprehensive guide to reading EGT's which helped me better understand what I'm looking at. I recently got an EGT installed at the manifold of my 2L-TE so Im now trying to get baseline readings before I modify the truck any further. Thanks again!
 
I tuned my 1hd-t to run at up to 750-800⁰c, and was comfortable pushing it to 900⁰c for short bursts.

Diesel combustion temps are far lower than what a typical gas engine sees day in day out with lighter pistons, basically the same metallurgy, and no oil spray to cool pistons.

I figure most people are unnecessarily conservative with EGTs in a turbo diesel.


My 13BT runs much the same, for mine i'm limited by the cooling system, couple of minutes at 700c + and water temp starts going up.
 
You guys are pushing your motors to 1400 degrees ?!
Yeah, my 1HDT saw 900c on (rare) occasion and absolutely no evidence of damage. - EGT is not the temp of the piston etc, remember it has ~90C oil from the jets below and a fresh cool air charge coming in above.

I wouldn't advocate running 900c sustained but circa 750c (1400f) won't hurt a DI engine.

If you're IDI, 1HZ, 2L-T etc. I'd be keeping to the mid 600s, but I've usually found coolant temp is a challenge in an IDI on a sustained pull unless you want to go the way of the TD42 crowd with steam vents in the cylinder head etc...
 
You guys are pushing your motors to 1400 degrees ?!

Yep. I ran mine tuned so I saw 750-800⁰C regularly. 900 ish if pushed really hard.

Mine was like this about 18 months before I tie down the engine after my turbo excluded and the engine swallowed the bits.

Absolutely zero evidence of heat damage.

These temps are not what you see every time you get in the vehicle. It takes somewhat extended periods of wide open throttle under load.

I was comfortable seeing 750-800⁰C as a normal peak. If you're aware of how EGTs work and impact the engine, when you're driving in a manner that's gonna create high EGTs, that's when to keep an eye on your gauges. If EGT keeps climbing, either back off, down shift, or keep your foot planted until you crest that hill and cruise down the other side
 

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