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+--- Thread: 617a factory EGT (/showthread.php?tid=7550)
617a factory EGT - bullonezero - 12-25-2016
Hello Folks,
Does anyone know what the factory EGTs for the OM617a (turbo) engines were?
As i proceed with some mods, i m curious to know what Mercedes thought was acceptable.
RE: 617a factory EGT - NZScott - 12-25-2016
1250 F for a few seconds, to quote the 1978(?) SAE paper MB did (of course in normal use they shouldn't be that high)
RE: 617a factory EGT - R-3350 - 12-25-2016
the maximum recommended sustained temp on the turbine inlet mentioned in the SAE paper is 800*C (1472*F). i might be hesitant to run that and instead recommend the standard rule of thumb which is 1250*F continuous and 1450*F for up to 10 seconds.
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![[Image: Screenshot%20from%202016-12-25%20214228_zpsgfocaa6y.png]](http://i346.photobucket.com/albums/p435/R-3350/Screenshot%20from%202016-12-25%20214228_zpsgfocaa6y.png)
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RE: 617a factory EGT - MFSuper90 - 12-25-2016
I've seen 1400 on my setup before, no problem. But like most said, not longer than a couple seconds. Mostly for the fact that we don't have a straight enough road or long enough hill for me to pull that hard that long.
RE: 617a factory EGT - NZScott - 12-26-2016
Aha, well I was close
Now, what would max continuous EGT be for my NA with no oil nozzles
RE: 617a factory EGT - Simpler=Better - 12-26-2016
THat's tough, rule of thumb I'd say keep it under 1000*F?
My turbo would hit 1100*F on long hills (2056V turbo, straight pipe exhaust)
RE: 617a factory EGT - NZScott - 12-26-2016
That was about my guess too. I should really install that EGT gauge of mine
RE: 617a factory EGT - MFSuper90 - 12-26-2016
1000F is pretty low. Most of our older Ag equipment are non-oil squirter engines. Including both of our pulling tractors which have both seen 1700F+. I think it's more about duration than temp. A friend of mine with a international 466 (non oiler engine) hit 1900F peak going down the track and didn't melt pistons. But the duration was very short.
I think a lot of people worry too much about egts, it's engines with whacked out timing and messed up injectors (in direct injection at least) that Burn pistons.
Just my .02 cents
RE: 617a factory EGT - NZScott - 12-27-2016
Veeeery interesting, thanks. IDI with flat top pistons supposedly can get away with high EGT than DI, but then MB pistons have a little dish for the prechamber tip so...
RE: 617a factory EGT - barrote - 12-27-2016
U Folks ,
I´ve run my 605 konstantly at 800ºC and the only thing that melted was the turbo vanes and turbine.... DI´s have issues with high EGT , but only if injector spray patern is not good.... happens when only one or two holes clogg and the others start to cut away the piston like a blow torch....
Squirts is another mith , at least in European models i don´t see a "squirtless" diesel since the 616 N/A . Or tractor engines like was mentioned above....
sorry to highjack....
RE: 617a factory EGT - Mallinman - 12-27-2016
Where do you get the 800c from?? Is that pre or post turbo?
RE: 617a factory EGT - barrote - 12-28-2016
hugrr , whats the point of measuring EGT after turbo? (BTW i use an aviation thermocouple, suited for 1200ºC)
800º C is not much usually i lift foot due to other overheating, coolant and oil....
regards
RE: 617a factory EGT - Mallinman - 12-28-2016
I know there's not much point measuring after just some people find it hard to find a suitable point pre turbo to mount the probe. Just wondered where urs was
RE: 617a factory EGT - barrote - 12-28-2016
It has to be pre turbo, there is no point in measuring post turbo.
below facing the grownd almost all collectors i´ve seen have a flat spot where u can drill and insert the probe in the stream, without interference with the other hardware....
right aside i use the EGP conection...
RE: 617a factory EGT - mrfajita - 01-01-2017
(12-26-2016, 12:26 AM)NZScott Aha, well I was close
Now, what would max continuous EGT be for my NA with no oil nozzles
My 77 N/A with a HY35 has been over 1000 many times. Today on a canyon run I hit 1300 a few times at 15psi, uphill flat out in 3rd gear. Been running it boosted since last spring, nothing has broken yet
RE: 617a factory EGT - barrote - 01-02-2017
1300 farenheit ..... pls don´t fool people bother
RE: 617a factory EGT - Evenglass - 01-02-2017
My 2 cents.
Metal doesn't melt until almost 2200*F so why are we so worried? Now days if you ask most diesel owners what high egt's are they'll answer 800*F but why is this? I believe this to be the surge in sales specspecifically DI engines. Most people don't realize diesels from the eighties and nineties such as Volkswagen turbo IDI routinely run 1400-1500F egt's every day in factory form. The difference is in tje combustion chamber design. The heads of newer DI engines are mostly flat with most of the combustion occurring in the concaved piston. If the DI piston gets too hot it will start to expand and soon weld itsitself to the cylinder wall at the very least score the bore, this happens at about 900-1200*F depending on desidesign. With IDI engines the combustion chamber is mostlmostly in the head, heads have alot of mass and can ababsorb alot of heat. Iron IDI heads can absorb lots of heat and thermal expansion is relatively the same as the iron block so gasket failfailure is less likely. IDI pistopistons are mostly flat and absorb much less heat than the DI pistons and do not expand as much. This is why piston and ring clearance is greater on DI engines. 1200F is nothing for an IDI engine. Here's a good article about EGTs
http://www.trucktrend.com/cool-trucks/0508dp-2003-ford-f350-cummins/
RE: 617a factory EGT - MFSuper90 - 01-02-2017
I agree with you evenglass, besides that a DI engine will melt a piston at 1200. My DI engine runs 1700 and didn't melt the piston to the cylinder wall. And our other Perkins ran at 1800 for 20 years.
RE: 617a factory EGT - Evenglass - 01-02-2017
(01-02-2017, 08:34 PM)MFSuper90 I agree with you evenglass, besides that a DI engine will melt a piston at 1200. My DI engine runs 1700 and didn't melt the piston to the cylinder wall. And our other Perkins ran at 1800 for 20 years.I think you meant "IDI" in the second part. Or maybe the older low pressure DI engines.
RE: 617a factory EGT - MFSuper90 - 01-03-2017
Nope. Perkins 4.318, 6.354, and IH dt466 that have all seen 1700+F. All direct injection engines
RE: 617a factory EGT - maxypriest - 01-04-2017
I did a few top speed runs in my W124/OM606/HX40super/8.00mm set up and measured 850C ish EGT post exhaust housing (please don’t shoot me!!! – I did not know the place to put it at the time) and this was with WOT for a good while – vid attached.
Ran out of revs – 174mph max so a 1:2:65 is going in the rear this year. What I did notice is that as the revs go over 5200 the power and EGT drop off as the fuelling is being pulled back as the governor cuts in. You can see she is running clean as a whistle as she passes the timing equipment.
https://www.youtube.com/watch?v=R5mg3_EjdbA
RE: 617a factory EGT - charlysays - 01-11-2017
(01-04-2017, 09:42 AM)maxypriest I did a few top speed runs in my W124/OM606/HX40super/8.00mm set up and measured 850C ish EGT post exhaust housing (please don’t shoot me!!! – I did not know the place to put it at the time) and this was with WOT for a good while – vid attached.
Ran out of revs – 174mph max so a 1:2:65 is going in the rear this year. What I did notice is that as the revs go over 5200 the power and EGT drop off as the fuelling is being pulled back as the governor cuts in. You can see she is running clean as a whistle as she passes the timing equipment.
https://www.youtube.com/watch?v=R5mg3_EjdbA
850C post turbo is likely to be atleast 950 pre turbo, could be over 1000! Good to know an OM606 and an oil cooled turbo can survive such stress. My OM605 with EDC and GT2871 turbo can see 850 pre turbo on a hill at full throttle. Normal daily driving and the hottest it gets is 550- 600