1939 R66 on Ebay

Darryl.Richman · Post by **Darryl.Richman** » Wed Jun 06, 2007 1:59 pm

My R12 has a similar mark. It also is stamped with OZ-74. You may *just* be able to see this all in the photo:

The Y 10 mark is on the top, just ahead of the bell housing. I have no idea what the significance of this mark is.

You may be able to make out the OZ-74 stamp on the flat area above the followers.

There are other stamps that BMW put on the cases. For the split case motors like my R12, there are two numbers that are stamped on both halves on the front right side. I don't know what they mean, but they originally matched. Similarly, the crank webs have numbers stamped into the sides, and they originally matched and lined up. The /3 and /2 tunnel motors have the gear train offset stamped into the top of the case.

EuroIron · Post by **EuroIron** » Wed Jun 06, 2007 2:02 pm

cast into the flange of one cylinder, right side, is "SMOP" and it also has stamped numbers

the left cylinder does not have these cast or stamped marks

and it has what appear to be skirt oiler holes drilled

Bruce Frey · Post by **Bruce Frey** » Wed Jun 06, 2007 4:15 pm

My R5 motor is also stamped OZ 80 just as your is. I believe your engine number stamp is authentic with the BMW roundels before and after the number. My R5 has no other stamps that indicate military possession, either.

It was usual for the both the cylinders and heads to be stamped with the engine number (or an abbreviation of it), however, I have also seen cylinders and heads without them.....probably replacement parts. On the cylinders, the number is usually on the upper side of the flange where it bolts to the engine. The number on the heads is usually on one side of the upper edge near the valve cover. I will look through my pix and try to post some examples.

If you are lucky enough to have these stamps (they are sometimes hard to see) that match the engine number, that is a good bonus and I would add it to your auction info.

I think it is typical to have oiler holes only on one side.

Good luck! Your auctions add a bit of life to eBay.

Best regards,

Bruce

EuroIron · Post by **EuroIron** » Wed Jun 06, 2007 7:51 pm

Thanks guys, I found Y only on the other side of the engine as well..... right next to the small rondel, and it looks like a post war rondel but careful measuring shows it to be different and obviously done with a very crisp and fresh stamp

weird stuff for sure and thanks again for all your help

EuroIron · Post by **EuroIron** » Thu Jun 07, 2007 3:02 pm

tell me, what are those raked tree forks actually correct for?

I have some that do not have raked trees as well

I have several sets of forks and many in parts but I'm thinking these are the wrong ones....... and I have no idea why it would appear to need cable holders for what would appear to be a double sided brake drum

EuroIron · Post by **EuroIron** » Fri Jun 08, 2007 2:20 pm

http://www.youtube.com/watch?v=tj49V13Iv-4

schrader7032 · Post by **schrader7032** » Fri Jun 08, 2007 4:34 pm

http://www.youtube.com/watch?v=tj49V13Iv-4

I was expecting someone to crank up a pre-war BMW near the end of the video...just a bunch of crickets, however...?

Kurt in S.A.

EuroIron · Post by **EuroIron** » Tue Jun 12, 2007 1:53 pm

you are correct, only crickets.........

appropriate, don't you think?

anyhow, so far it is looking like the R66 is being adopted

thank you guys for your help

VBMWMO · Post by **VBMWMO** » Mon Feb 15, 2010 2:51 pm

I'm sure there must be some historical or technical bits to be gleaned.