om642 pre-turbine temperature limit?

[saunders1232011]

Good evening all,

Does anyone know the limit of the pre-turbine gas temperature on the om642?
I have a hybrid turbo of the gt2056v taken to gt2365, I would assume the turbine wheel would have be ok for a minimum of 850°C. My main concern is the exhaust valve temperature limit. I have a thermocouple pre-turbine so I can monitor temperatures and adjust my fuelling accordingly.

Thanks

 

[Elfat]

hi sorry i know this is a late thread but did you manage to get it all complete in the end?

 

[saunders1232011]

Yeah I am running approximately 900°C pre-turbine when heat soaked. (140+MPH)
Next step in measuring the depression at the compressor in to see whether a more "flowing" air intake system would be of much benefit.

 

[alexanderfoti]

It wont last long at 900C pre turbine, considering that it would have cooled slightly since leaving the head, which is aluminium.

 

[saunders1232011]

Indeed it is aluminium, but how long is it at 900°C for... It's very rare the car is doing speeds in excess of 130 MPH.

Additionally I have run engines with Aluminium Heads at 900°C port temps for hundreds of hours on test beds with no issues.
My main concern is the exhaust valve rather than the head itself... It is very subjective to the materials MB used on this particular engine...

Some turbo's are now specified to withstand 1050°C exhaust gas temperature. The heads are still aluminium...

 

[alexanderfoti]

But that means you are running EGT's close to 1050C. What are the stock readings?

 

[saunders1232011]

I think you mis-understood, I'm not running EGT's near 1050°C, I was just stating that it is possible with Aluminium heads.

 

[alexanderfoti]

you are if pre turbine temp is 900, depending on where you have the probe?

 

[saunders1232011]

Definitely not.
My thermocouple is placed 100mm before the turbine wheel.


I have run engines on test beds with port and pre-turbine thermocouples. Or for supercharged engines (without turbo chargers) a thermocouple just before the catalyst. You may loose a few °C from the valve to the catalyst or turbo, sometimes believe it or not the temperature can increase. This is based on production engines.
Turbo's mounted on fancy motorsport exhaust manifolds may loose slightly more heat due to the length of the pipework.

For turbo applications you can loose around 100°C through the turbine. ie. 900 pre turbine and 800 post turbine.

 

[alexanderfoti]

What are the stock readings?