The Nissan Diesel in US pickups of 80s vintage was a copy of one of the
versions of the OM 636, an engine that MB stopped production on in 1959, as
being outdated. I think your engine is the same series. The OM 636 had
versions with banks of 2 cylinders that bolt to the crankcase, as well as
one piece block versions. I believe the OM 636 was designed in the 30s and
powered the 170D, the 180D and the 180Db. It was replaced by the OM621,
which is essentially the same block and head as OM615 and 616 and shares
some parts with the 617.
On second thought, I think the industrial versions of the 636 lived on into
the 60s and beyond in refer units, forklifts and such. The Farhrtzoid
(PKW, or automotive) versions stopped production in about 1959.
Nissan 4 cyl gassers were direct copies of the engine used in the 190c, I
think that was M121? and the famed Z 6 cyl engine is a copy of the M180
engine. I am not sure if these were licensed or just knock-offs.
Then again my 87 Nissan Patrol has glow plugs but I think they just copied
the Merc diesel engine, except it has pushrods.
Loren Faeth
