engine dating

[Rocket Racer]

My 1960 super rocket project has limited history prior to 1980 when it was in the uk with the current engine fitted, earlier papers do not mention the engine number but in 1972 the original log book was recorded as being destroyed in Derbys and only notes the frame number. But at least the engine and frame have been together for at least 30 years now although the engine number suggests a 1961 build. So swapped in at some point.
However my thread relates to the common date stamping usually found under the front of the engine. In this engines case the motor appears to be date stamped 20.2.67
Could this mean it was a factory spare, not sold until 1967? Thats well after the A10's were obsolete... which seems odd or unlikely
Any thoughts from the forum?

[muskrat]

G'day RR, I'd guess your thought might be correct. I doubt it would have been stamped at the agents at swap over, but at the factory on despatch.
Cheers

[trevinoz]

Maybe the "stamper" didn't have his glasses on and picked up the 7 instead of the 1.

Trev.

[Rocket Racer]

thanks guys, my thoughts too! possibly a dispatch date, or an error in the stamping.
My understanding is BSA policy was to provide parts support for models up to 10 years old, so a 1967 stamp doesn't seem out of the question, well past a warranty swap, but fitted after a blow up perhaps. In the absence of any other hypothesis I'm going to assume the engine was fitted in 1967 (or thereabouts).

[trevinoz]

RR,
             My understanding of the dates stamped on the cases is that they are the machining or casting date.
On the plunger cases you will find a different date on each side so is most likely a casting date.
Let the debate begin!

Trev.

[WozzA]

I thought we covered the dateing issue here..   
http://www.a7a10.net/forum/index.php?topic=6397.msg44090#msg44090

[Rocket Racer]

I thought we covered the dateing issue here..   
http://www.a7a10.net/forum/index.php?topic=6397.msg44090#msg44090

Thanks for that, as usual everything gets discussed on numerous threads  but still doesnt comprehensively answer the question, the engine number indicates a '61 motor, but as Muskrat suggests may have sat in the factory til 67 as a spare?? until my '60 needed a fresh motor perhaps.
All the other engine cases I have on the shelf have equivalent dates that coincide to the engine number year or general bike dating, but 1967 doesnt fit that logic and which was what threw me.
if the engine was never sold in a bike in the usual sense that might explain my odd year stamp.
I have previously sent an email to the UK BSAOC to try and further understand the history of the bike, but didnt hear back. so have yet to send them any money
I'll continue to assume the date is a dispatch from factory date