The bottom end is probably finished being reassembled at the machine shop, but they called me in
for some consultation... The original head has a crater in the #2 combustion chamber, eaten away by
corrosion, maybe 1/4" deep & 5/8" wide. The 190 head,that I got (amazingly) at a local junkyard,
has badly pitted valve seats. They don't have confidence in replacement valve seats staying in, and
they don't have confidence in a head being built up by hot welding and not being warped. Off to do
some more digging...
May 4
Not easy to find this head around. It is a 9:1 compression head.
May 13
The 121.940, in the model 200 of '65-'68, and this engine, the 121.941, share the 9:1 head. Here
are applicable #s for the 9:1 -
casting # 121 016 22 01 (this is the one from the bus)
121 016 26 01
head part # 121 010 21 21
121 010 25 21
121 010 36 21
121 010 39 21
121 010 69 21 (available from MB Classic @ EUR 876.53)
The M121 parts book doesn't show either of those casting #s, but it does show the part #s,
several of which point specifically to the M121.941 of the 319B.
Unfortunately for finding spares, the 200 wasn't sold in the US either...
May 14
Always helpful Jim Axman pointed me toward American Cylinder Head, Inc., where Tim Graney
said he'd take a look at the original head if I send it out - apparently they do this kind of repair
enough to know what they're doing.
May 28
Tim has the head, says nothing looks insurmountable.