What engine oil for Onan 12 djc

[Treedog]

Just purchased a 12 djc. It's a 1967 model, but damn near perfect. Runs like a top, and not much sign of wear and tear on it. What type of engine oil should I use? Do these older engines with flat top lifters require a zinc based oil? Also does anybody have an idea of approximate value of these units? I'll be using it for home auxiliary power, to offset our totally off-grid setup. Any opinions on this application would also be appreciated. Thanks-

[DaveVA78Chieftain]

Please refer to pdf page 17 of http://www.twinslan.net/~n0nas/manuals/onan/932-0112%20Onan%20Post-Sale%20Literature%20%28Manuals%29%20Index%20%2807-1998%29.pdf for the correct manual numbers for the DJC generator you have.  You will need to decode the SPEC number to correctly ID the manuals you need.

[DaveVA78Chieftain]

This Army manual contains a large portion of the information for the Onan 10KW Diesel DJC (Army version number MEP-003A)
http://igor.chudov.com/projects/manuals/ONAN-DJC-MEP-003A-Manual.pdf

[Rickf1985]

Engine oil would be 15W-40 Rotella or Delo or similar diesel motor oils. I have two of the MEP-002 5KW units.
I also have all of the manuals and a source for the ones you need if you want them.