EGT gauge is back up and running, however, the probe is after the turbo.  In my previous trucks I have been in the exhaust manifold, and 1200* was the peak I ever wanted to see..  My question is, because I can't move the probe before towing this week/weekend.  What temp would you guys say is a conservative number to stay at or below?

 

Thank you

21 minutes ago, Cowboy said:

reality hit me like a brick and I realized no one is going to grab a calculator while pulling a hill to find if there temps are acceptable.

 

This is well outside the common Joe Cummins owner. For someone that is pushing to grab every last bit of power out of engine, this might be an excellent article to be put together in the article database.

Edited July 1, 20177 yr by Mopar1973Man

Good data!! 

 

I'll bite on the drive pressure bit. It's been a couple years since I ran a drive pressure gauge (it's on the shelf and needs some wires moved since the Touch took up a pillar spot), but I think I generally ran a lower drive pressure ratio than you did and it took quite a bit of fuel and rpms to even get to 1:1 and rarely over 1.2:1 (DP:Boost). That could be where you are getting more than 10° per psi. 

 

I'll be doing some towing over the next week and I'll try to take some notes. I should get my drive pressure gauge up and running. It's literally 3' of wire and done. 

 

On a side note, 1400°+ while towing would scare me :-)

So I was 21.3K GCW and towed in temps up to 104° at 3,000' and 99° at 4,500'. 

 

12-14°:1 psi is normal for varying throttle and rpms. Under constant loads longer than 30 seconds it almost always stabilizes at 10-11°:1 psi, and sometimes it took longer than 30 seconds but we already know how slow post is to react. 

 

The more I monitor post the more I want to say that it actually is a better indicator of motor heat soak and thus would be easier to drive. It is nice having both thou. 

nevermind.  posted above.  It is interesting to see the differential above!  

 

I kinda am starting to think that the turbine EGT limitations are not from the turbine wheel itself, but from the heat transfer capacity of the bearings/oil flow.  

 

I agree that burned pistons are more of a concern than a turbine though. Turbines tend to be killed due to hot shutdowns. 

 

On another note, I recall reading in a Northrop A&P text from WW2 that the majority of the heat from a valve travels through the stem, not the seat.  Pistons and burned valves are a bit of a concern... but not a huge one as our engines have decent oiling.  

Edited July 9, 20177 yr by CSM

I'd like to think that the bearing isn't seeing all that heat, also with mine being a water cooled turbo if the bearing was the deciding factor on heat transfer mine should have a bigger delta. 

 

I think drive pressure may be the culprit as more drive pressure will result in a bigger pressure drop which leads to a higher temperature drop.