1982 6/71 T inline 6 ,2 Stroke Diesel engine what's correct oil ?

Pascal is asking because this should have be caught in survey.

My DD 6-71 TIB engines have oil capacity listed as 28 quarts/ 7 Gallons. I use Shell Rotella T1 40 W and boat on northern Lake Michigan / Lake Huron.
At 2100 rpm my engines are steady at 165 degrees over a 3 hr cruise.
1988 Viking 44 Motor Yacht with dry weight of 40,000 #.
Similar boat to MBevins.

Racerx4772.
I have a 43 Viking DC / MY, and when I bought it used in 1990, it would overheat on the port engine. It turned out to be the exhaust riser. Viking install cast iron risers, and they can get rusty. The problem was it was not discovered by the engine survey before I bought the boat, because it seems that the rust particles sometimes get pulled up behind the diffuser, and sometimes only some of it does. Please get a water pressure gauge, and insert it in one of the zinc holes in the fuel cooler. It should only have a few pounds of PSI @ 2000RPM. Check it a few times, and maybe compare it to the other engine. At one point during my delivery trip, the pressure got so high that it blew the hose right off the pipe that connects to the exhaust.
I was very upset with the surveyor because of this because he found no problem, but he explained to me how the rust will settle down at idle, and then be drawn up against the diffuser when throttling up. This made sense, as this was an Intracoastal trip, and constantly fast and slow going, and waiting for bridges. The engine was constantly running much hotter than the other one, but after waiting for one bridge for a while, I then got back up to speed and the hose came right off. It is worth checking. I replaced both risers with stainless steel ones and have never had another problem.
Dennis

Had the same problem and the same solution in 2016.

You can't believe how much rust and scale will accumulate in the mixing elbow.
I removed the exhaust hose from the mixing elbow and the offset tube and could see all the crap laying on the water ports of the elbow.

If it is the elbow, don't good around trying to clean it, replace them both.

Unsure who you were asking for pictures from but here is a picture of an offset tube and one of a mixing elbow next to 2 old turbos.