crankcase oil looks clean

[jerseyboy]

I checked the dip stick on my freshly rebuilt port engine and it looks like it was just changed and not run at all.
The boat has about 4 hours on the rebuild 8-53 Detroit but I always thought the diesel oil turned black right away. I'm I wrong or do I need to put a lot more hours on it?

 

[Jims43DC]

I checked the dip stick on my freshly rebuilt port engine and it looks like it was just changed and not run at all.
The boat has about 4 hours on the rebuild 8-53 Detroit but I always thought the diesel oil turned black right away. I'm I wrong or do I need to put a lot more hours on it?

I have 43 hours on my last oil change (671's) and the oil is still clean not black and haven't had to add any yet.

 

[cww]

It depends on how you ran it. If it’s low load running it won’t turn black all that quickly. On a detroit you break them in by flogging the crap out of them. Evidently that seats the rings a lot better than babying it. My mechanic wouldn’t warranty the rebuilds unless he was onboard for the initial break-in, which consisted of running around the river with them almost on the pins for several hours. If you’re going easy on them, don’t.

 

[madhatter1]

My worn out 1973 8-71 TIs were like that. Nice clear oil always. My 8-92's oil is pitch black like the Cummins on the 34. Have no idea why.