• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

Cylinder Head Identification

b25bsaboy

New member
Good afternoon to everyone,

Several week's ago I bought a collection of parts for Airheads and Norton Commando parts. There was more Norton parts than Airhead but in the |pile I came up with a dirty pair of double plugged BMW Airhead Cylinder Heads. They were dirty as H*#l and took them and got them Vapor Cleaned at a local shop here in Calgary. The difference is amazing, but I have no idea what these heads will fit, thus I am asking if anyone has any idea what I have?
On the inside where the valves are it is stamped 30/22.
 

Attachments

  • IMG_2337.jpg
    IMG_2337.jpg
    57 KB · Views: 252
  • IMG_2340.jpg
    IMG_2340.jpg
    62.4 KB · Views: 246
Last edited:
No serial number or part number on the heads. As a general rule, BMW never puts part numbers on parts. The number you do see in the figures is a mold number for which there is no information about.
 
Is that the serial number on the heads? The microfiche for BMW parts should be of help. St.
Thank you for the comment, but Kurt is right about BMW not putting parts numbers on castings. What you do see is a foundry forging number.
In comparing my heads on the other heads under my comment, it stricks me that the two heads are a matched pair.
If you look at the L10 - R10 (left and right side)
1 263 947 (L10((left side)) and 1 263 947 (R10((right side))?
SiCu is a foundry metallurgical # of what the head material is?
Si - Silicon, and Cu - Copper which is mixed in with the aluminum for heat treating to stress relieve?
 
Last edited:
The L10 and R10 probably indicates they are 1000cc heads. The SiCu does represent something about the aluminum alloy. I found an old post by Oak where he said the silicon was approximately 8% and the copper was approximately 3.5%. Oak was a metallurgist.
 
does it make any sense to measure the intake and exhaust ports? didn't the the early R100 have 40 mm I, 40mm Exh. just wondering if that could get you one step closer.
 
does it make any sense to measure the intake and exhaust ports? didn't the the early R100 have 40 mm I, 40mm Exh. just wondering if that could get you one step closer.
Your comment makes sense, as the chap whose parts I bought from also had a 1979 R100RT with I believe 40mm Bing carbs on the machine . Will go look see!
 
Rick:

Dave Anderson (Anderwerks) can figure out what they are, for you.
 
Last edited:
Measure the ID of the exhaust ports and the diameter of the ground/angled portion of the valve seats.
Good morning Anton! BeforeI went to bed last night, took a micrometer out into the shop and measure the exhaust ports and they are .040 mm. So that answers a few issues.
The 1979 BMW R100RT that was purchased along with the parts has .040mm Bing carbs on the machine.
 
40mm (.040 is a very different number) exhaust ports pretty much narrows it down to a '77-era big-valve R100 head. I have a '79 R100RT in parts and I have those same heads. 44mm intake and 40mm exhaust valves.
 
Maybe Rick meant 0.04 meters!! I just measured the valves that came out of my '78 R100/7. The intakes are 42mm while the exhaust are 40mm.
 
Maybe Rick meant 0.04 meters!! I just measured the valves that came out of my '78 R100/7. The intakes are 42mm while the exhaust are 40mm.

Kurt, Sorry for the delay in responding to clear the air. Went out and re-measured the inside diameter of the inlet spigot for the 40mm carburetor and it is 41mm.
Here is the photo that I guess says so!
 

Attachments

  • IMG_2366.jpg
    IMG_2366.jpg
    44.1 KB · Views: 86
Good afternoon to everyone,

Several week's ago I bought a collection of parts for Airheads and Norton Commando parts. There was more Norton parts than Airhead but in the |pile I came up with a dirty pair of double plugged BMW Airhead Cylinder Heads. They were dirty as H*#l and took them and got them Vapor Cleaned at a local shop here in Calgary. The difference is amazing, but I have no idea what these heads will fit, thus I am asking if anyone has any idea what I have?
On the inside where the valves are it is stamped 30/22.

Here are pictures of my heads from my 1977 R100RS. The casting number matches yours. I'd call that good for identifying them as 1977 R100 heads.

IMG_8370.jpg

IMG_9130.jpg

Best.
Brook Reams.
 
Back
Top