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

[PEOPLES]

Good morning,

I have a old OJ50 Bandeirante (j4-type-Landcruiser) witht he OM314 Diesel Engine from Mercedes.
I bolted a turbo on it (still planning for the intercooler, but not now) and I have a EGT-Indicator between engine and turbine.

The engine has no features, a normal turboengine has, linke cooled valves, piston-cooling (via oil from beneath), etc. Just a classic normal aspirated diesel engine.

To get the benefit of the turbo I cranked up the fuel a little bit and right now I have 85hp on the rear wheel, where 85hp on the engine is stock. I keep the EGT below 650°C. Short term up to 700°C allowed. The turbo makes around 14PSI at full boost and high RPM. Nothing regulated

I recently saw some posts here, where people talked and mentioned, not going above 700°C (1200-1300°F) would mean, not full potentail of the engine. So what do you guys think, my engine can deal with? Is there a "kink-point" balancing between lifetime of the engine and power?

Thanks a lot

Michael

 

[William839]

I try not to go over 1300 at all personally , if you can keep it under 1100 that would be ideal .

 

[RyanMiller]

I try not to go over 1300 at all personally , if you can keep it under 1100 that would be ideal .

1300F is 704 C, and I abide by similar

 

[DrDuc]

I always tried to keep mine at 1250 or under.

 

[William839]

Also depends how long your cruising ? Are we talking maintained temps? My truck runs hotter at 1000-1100 cruising 70-75

 

[mudgudgeon]

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.

Stoichiometric Combustion

Stoichiometric combustion and excess air.

www.engineeringtoolbox.com

 

[Dougal]

Indirect injection engines can run hotter than direct injection. Because the piston bowl in direct injection engines makes the pistons run hotter.

 

[mudgudgeon]

Anyone got access to this journal?

https://journals.sagepub.com/doi/pdf/10.1243/146808705X7428

 

[PEOPLES]

Also depends how long your cruising ? Are we talking maintained temps? My truck runs hotter at 1000-1100 cruising 70-75

My LC is not so fast, usually cruise speed is around 55-60mph, at this speed no issues with the temp. Also going long climbs at that speed, the engines stays below 1000-1100°F. The engine only makes 3000min-1 and feels most comfortable at around 2400. But I'm not pushing it.

It is actually a direct injection engine, but an old one. Those old mercedes engines used to work in little comercial trucks with 7.5t. So I think the engine is used (designed for) to high loads over long time, but without turbo.

My concern is, that this engine was never designed to run with a turbo, I just forced him to do so (and it works well), but pistons, valves, etc. had been never designed for. That doesn't mean, that it is a problem, but I want to stay on the save side.

Thanks a lot guys, I guess I will stay with what I have know, doesn't seem to be so false. The intercooler along with a different pinion-set in the diffs are still on my list.

 

[bold2013]

My 1hdt cruises the highway at 800-1000f and upto 1100-1200f with hills and acceleration.

 

[William839]

My 1hdt cruises the highway at 800-1000f and upto 1100-1200f with hills and acceleration.

Is that stock? Is the pyro pre turbo or post turbo in the exhaust ?

 

[bold2013]

Pre turbo. Only have 3in turbo back exhaust upgrade.

 

[William839]

Pre turbo. Only have 3in turbo back exhaust upgrade.

That’s high but also what I cruise at , I’m in the process of trying to turn her down and run around 800

 

[ATL Cruiser]

That’s high but also what I cruise at , I’m in the process of trying to turn her down and run around 800

That's also what I run at pre-turbo. 800F.

It's still WAY MORE power than stock. And it gives me a large safety buffer at the same time.

 

[ATL Cruiser]

Anyone got access to this journal?

https://journals.sagepub.com/doi/pdf/10.1243/146808705X7428

What are you trying to read? I could dig it up I'm sure.

Edit: my bad. I see it now. It had a pop up on top of it. I'll dig this up.

Edit #2: got it. Shoot me a PM. Super interesting paper.

 

[bold2013]

800f at about 70 on cruise.

I am planning to replace my 315/75/16 with 255/85/16 along with updating the turbo and adding an FMIC this spring.

 

[William839]

800f at about 70 on cruise.

I am planning to replace my 315/75/16 with 255/85/16 along with updating the turbo and adding an FMIC this spring.

That’s a decent number already..

 

[Dougal]

Cruise EGT is about gearing and load. Your tune can't change it much, max fuel has no effect and timing only has a small effect.

 

[bold2013]

I’m not worried about it I just wanted to improve things before I tow a small trailer.

 

[mudgudgeon]

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.