Diesel Engines Running Underloaded / Lube Problems?

While running 80% load would be ideal......running at less wouldn't have catastrophic effects as described, and the 3512's computers do keep them running pretty clean at lower RPM's, albeit not as ideal as 80% load. There are very few boats that run at 80% load most of the time. Look at all of the push boats on the Mississippi and Tennessee rivers, they rarely run at 80% load. Once they get the barges moving, going downriver, they run a lot less than 80% load.......
The engines won't pit when they're running under the circumstances, because they are running and 190 degrees and there is no condensation in them when they're running for 2 weeks straight at operating temp.

So chief, if the combustion temperature is 400*F what do you suppose the charge air temperature is just before injection?

You might want to review your class notes before posting some of this stuff. because some readers might believe it is true.

I understand all of this and it is good info. However, during a transatlantic crossing where the engines are never shut down, except maybe briefly to check oil level, there is no condensation that will form, so that is not a concern. When you get to the otherside, you're going to do oil changes within hours or days. I've worked on several megayachts with 3512's, about a decade ago, and they rarely cruised at 80% load.

I was the test Captain for the MAN common rails (2nd set in the United States) where MAN of North America did 7 days of seatrials in order to setup their fuel curves and computer parameters for the Common Rails. Which is a different story altogether.

Easy guys, keep it professional!

I guess that about sums up both your personal and professional standards. Wouldn't it have been more productive to the membership if you would just stick to the topic, answer the very reasonable question, and share some of what you profess to know about engine operations?

If you are going to post scare mongering myths and state things like combustion temperatures it would behoove you to at least be able to support your statements and at the very least provide real information to support what you claim is "real" data concerning combustion chamber conditions.

Let me sharpen the stick a bit; If you are convinced that the combustion temperature is 400*F perhaps you would tell us what the temperature of the charge air is in the cylinder at the start of injection. While you are at it, what do you believe (because it is glaringly apparent you don't know) is the ignition temperature of diesel fuel?

There is a term for that:

Urban Dictionary: Polishing a turd

To everyone posting in this thread, please be nice. There is no reason to antagonize. Some of you are already in enough agony.

temps

I would suggest that you do learn about charge air temps as any real "marine engineer" and in particular those who have spent their time obtaining combined diesel / steam un-limited Chief Engineers licenses will tell you that those temps are 'kinda' important.

Reading your posts I did wonder if you were indeed an engineer but then noticed your spelling of the word "tempetures" and realized that only a guy who has spent years gaining knowledge of how engines work and in particular watching all of those pressure and "Temperature" gauges did not have time to learn how to spell on that week long course at MAN !.

1: You shouldn't have posted nonsense to begin with.

2: You should have responded to a reasonable question with information to support your statements regarding cylinder conditions.

3: You should stick to the topic, particularly if it is one you started.

4: You should check your "facts" before publishing them.

5: If you are going to give advice about diesel engine operations in this forum you had better do your homework first. Don't bring a noodle to a knife fight when you get poked for posting BS.

Your reaction to being called out for posting nonsense is why people are afraid to ask questions here. No one gets nailed for asking even the most basic newbie question but when someone comes along and pretends to be an expert while posting complete nonsense it tends to poison the well.

I wonder

C4ENG,

"Does charge air have anything to do with your aftercooler temperature? I always wondered that.."

Asking a question like that makes me wonder if you know how a diesel engine works. Besides checking your facts think very carefully about your question before posting.

...a little hint, do you have any idea what goes through your aftercooler ?

Where did you get those numbers?

numbers

not sure but he probably stayed in a Holiday Inn last night

This is really sad. C4ENG has been expertly corrected. Is it necessary to continue? PLEASE... let it go.