I don't know for sure about the OM617, but the first 6.9 IDI Ford I bought was 180 degrees out of time - and it still ran!

Took a shot of ether to get it started, it smoked like a mosquito fogger, and it barely had enough power to get up to 60 mph (with your foot on the floor on level ground), but it still ran. I drove it home like that.

Based on that experience and how similar the two engines are in terms of construction and principles of operation, I'm going to go out on a limb here and say that I'll bet an OM617 would run at 11* atdc...

__________________
1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown