I worked on and for Detroit Diesel for years. When I lived in Regina, Saskatchewan, I would frequently get sent to a coal mine outside Estevan in the south east corner of the province to work on the 12V71 haul truck engines or the Allison powershift transmissions. One time I got sent down and told I did not need the usual parts. When I got there I was asked to tune up a 2300CID Cummins V12 in an Easyminer. The radiator is about 12 feet by 12 feet. All hydraulic drive, 4 Cat D8 undercarriages with hydraulic motors. Under it is a large drum with carbide cutters to chew up the coal which then gets on a conveyor into the haul trucks. The shop manual was in their library. Now Cummins hiway truck engines were 855CID. They also made a larger inline 6 of 1150CID. Then they had a 1710 cube V12 which was more or less 2 855 engines in one block. They did the same to the 1150 to get the 2300 V12.
The next week I got sent down again to tune it up again. I asked if I had made an error the week before. No, you did goodbut we had 4 other guys out to tune it up and liked the way it ran best when you did it. 2 mechanics from Cummins and 2 independent mechanics. The week after that I had to go down to tune up a Detroit 12V71 which always invariably involved an inframe overhaul as they worked too hard coming out of the pit. The radiator was out of the Easyminer. A welder had caught it on fire which with coal dust, diesel fuel and hydraulic oil all soaked up burned like crazy. But the engine ran good when they got it all back together.