Wierd Engine Number

[Lightningpower]

Hi,
I dragged home a few boxes of A7/A10 parts tonight and am at a total loss about the engine number.  The frame that was included was CA7.32XX, and has all the appearances of an early (1954) swinging arm frame.  The light green paint leaves me thinking it was an A7.  The Engine, however, is boggling me.  The numbers are all genuine (looking) font and I am sure they've not been doctored.  The problem is this: the prefix doesn't exist in the books.  The engine number is: FA7.XXXXX.  It's a really big number that suggests end-of-the-line, but I can't find FA7 anywhere but on frames.  The engine is also stamped HHC.  What is the collective wisdom?  It came with a rev drive on the timing cover, a K2FC mag, and an alloy head that was detached.  Thanks for any help!
-CG

[A10Boy]

Have you accidentally mixed the numbers up? CA7 is an engine number and FA7 is a frame number.

HHC means High Compression pistons and sports cam. Together with an ally head, rev counter and F2FC, without checking the books, I think you could have a shooting star.

[Lightningpower]

Unfortunately, I've not mixed the numbers up.  I doubt they were mixed up at the factory too, because I would think that different people stamped the frames and engines.  If it was a Shooting Star, then it should have "SS" in the engine number.  I've had wierd numbers before and BSAOC has made sense of them for me.  Sometimes things were mis-stamped.

[dpaddock]

I'm fairly certain that CA7 was the frame prefix used for the Golden Flash and Road Rocket in 1954 and 1955, and they were the first of the swing arm frames.

CA7 was also the prefix for the A7 (not Shooting Star) engines in those two years.

David

[trevinoz]

Maybe a restamp?
                               Trev.

[bsa-bill]

It's possible BSA would still have crankcases cast after the date the model ceased production ( stock for spare ? )

Could well be your engine was rebuilt at a later stage and re-stamped (perhaps wrongly), by whom and when may well have to remain a mystery unless you have any POs names and address

[Beezageezauk]

Just my thoughts on this one!!

A guy buys a new bike in late '59 with frame number FA7.115XX.

Somehow the engine (and bike) gets damaged in 1963 and is taken in to a dealers for repair.

Maybe the crankcases have been sent to a specialist alloy welder who reckons they are beyond repair and new ones are ordered from BSA.

By the time the new cases arrive the original cases have been scrapped or simply unavailable.

The bike repairer won't have the title or registration documents at hand so an assumption is made that the engine number is the same as the frame number so the new cases were stamped up with the frame number.  I believe that Triumphs always had true matching engine and frame numbers!!  If so, this could be a valid reason for using the frame number on the engine.

Ok...it's just my thoughts...but I suppose it's a possibility!!

Beezageezauk.

[bsa-bill]

crankcase belly numbers match.  So much for the replaced crank-half theory

Not necessarily, anyone knowing what they were doing would replace the whole crankcase, they are matched pairs which is the reason for the number on each half.

BSA would not supply ONE half of a crankcase, although the parts book shows a number for a 'right hand crankcase' there is a notation at the page bottom that this part is supplied only as a complete crankcase

[chaterlea25]

HI, Lightningpower
The staggered fin barrells are the latest types for A10's
61? onwards
HTH
John O R

[Lightningpower]

Race engine! Now to find the frame!