Does this letter "H" signify anything - its on the barrel of a recently acquired engine. I looked at 3 others in the shop and every one had a different letter on the barrel. (if its too fuzzy on this post, you can click to view the full image)

Thanks!Chris

From M20

email (option): chris@classicbikebooks.com

I think you will find only L, M or H stamped on the barrels- on later models at least, this signified the bore tolerance (Low, Medium and High) and the original piston letter would match the cylinder tolerance. Pistons are stamped the same way, L, M or H.
Vince
(Edit - now I see on the large photo that it looks cast into the cylinder- so my previous info is not relevant to this particular case, as the cylinder would be stamped after the boring was complete))

email (option): vinver@ns.sympatico.ca

Thanks Vincent - yes, the letter is cast, not stamped, but your info is still useful because I have seen those stamped letters and wondered what they mean too, and now I know!

BTW - this latest engine was lifted from Canada just this weekend along with 2 gearboxes.

email (option): chris@classicbikebooks.com

What, an engine from Canada? Pity!
What part of Canada if I may ask, and where are you located? Not much M20 stuff around the east coast that I'm not aware of yet, most of what I have been accumulating for my M20 has had to come from abroad.
Vincent

email (option): vinver@ns.sympatico.ca

Hi Vincent,

Got the engine (a rebuild from India) and the gearboxes from a dealer near Sarnia Ont who knew my dad and I have a penchant for these thing. If he comes up with much more I"ll let you know! Actually these were sitting in his stock taking up room for years and he just wanted rid of it - !!! (no it wasn't free, wouldn't that have been the icing on the cake!)

I used to live in Valcourt, Quebec, but haven't been there for many years and now I live in the USA. Are you in Nova Scotia? Just a guess based on the "ns" in your email!

Chris

email (option): chris@classicbikebooks.com

hi ,ive just checked five bsrrels,only one has a square cas on ,no letter.india eh ,maybe a caste number,hindu perhaps cheers rick

email (option): richardholt@rocketmail.com

rick

maybe a caste number,hindu perhaps cheers rick

email (option): chris@classicbikebooks.com

Chris,

Curious...Are you in Wisconsin now?

cheers, Scott

Scott - yes, Wisconsin. Howdya guess? (probably not too difficult to guess!)

email (option): chris@classicbikebooks.com

Hey Chris,

Nice to see you here!

We shall have to get together for a ride
when we meet up at some event.

If you are ever in my neck of the woods, my door is open to you and any M20 fanatics.

Cheers,

Robb

email (option): britool51@hotmail.com

Robb - I'll be over for Thanksgiving - not your house Robb, my brother's, down the road a bit in Brighton (the other side of Lansing from you). Probably a tad cold though for riding, but if its a mild weekend, maybe?

email (option): chris@classicbikebooks.com

Maybe it's the difference between sleeved and unsleeved barrels?

Wassup with you Yanks? Can't you think up names for your towns? Brighton and Lancing are on the south coast of England, and always will be Ron

email (option): ronpier@talk21.com

Well, thanks for everyone's non-help so far (Vincent and Douglas excepted!)

Did BSA have their own foundry / casting dept? Perhaps this cast letter has some relationship to BSA's manufacturing date; or if they had suppliers, then it may be the symbol of a supplier.

I asked my dad, who worked at BSA post-war (one of his duties as a young apprentice was unloading the returning railcars full of military bikes, and sorting out the BSAs from what he called "the junk" and tossing some of "the junk" into the canal...) - he thought BSA generally manufactured its own cast iron parts, but he suspects during a time of extremely high demand (such as WWII) that they would have pulled in outside resources. Other than the M20s, he's not much into cast iron, more of an alloy guy, him! Anyway, if anyone has info on BSA cast iron manufacturing that would be interesting to hear; meanwhile we'll see what we can find out on our side.

Anyway, it matters not, I suppose. Its just more interesting trivia when it comes to these old warhorses.

Thanks!

email (option): chris@classicbikebooks.com

usealy if an number or letter is cast into a piece it is more to do with the casting so it any problems accure they know which caster it came from ie the buck is distorted or poor metal is used in that pour

email (option): chris@classicbikebooks.com

Chris,

How did I know Wisconsin? The email address helped (no, not too hard). I've bought some books from your business (www.classicbikebooks.com/). Great service. Let me know if you are ever in Madison.

cheers, Scott

email (option): sd246@sbcglobal.net

Acton, Alton, Andover, Arundel, Berwick, Buxton, Enfield, Falmouth, Hartland, Scarborough, Southport. Names of some towns here in Maine. I guess that's why they call us "New England"!

BSA had extensive 'in house' casting facilities for ferrous and non ferrous castings of all types,including specialist alloy castings, to the extent that they supplied other firms within the motorcycle and related industries...There was no other motorcycle manufacturer that came even close to BSA in the range and volume of products manufactured..Ian

You've confirmed what I've always known: BSA Rules!

email (option): chris@classicbikebooks.com

hi chris,check out my post bsa factory tour,you can search using the box above it'll open your eyes.i work in engineering you find these tags all over castings,i think sometimes its the pattern maker just leaving his monica,have you ever walked past newly laid concrete without dirtying a finger? cheers rick

email (option): richardholt@rocketmail.com