Vintage BMW Motorcycle Owners

Hi all - I have a problem!

The R66 project is going well but there are no numbers on the case, the barrels or the head. There is sometyhing on the barrels but I don't know what it means. Can anyone help me with identifying the marks on the barrels? Cheers. Mark.

Hi - very cool project!

2-39, and 3-39 -- I think those are foundry / casting date codes - the first number being either the week or month, and then the year (1939).

No clue what "SMOP" means!

I think the later R66 cylinders had a head oil return tube?

-Chris