Found matched cases stamped A65LC. Guessed the C meant Competition which made me want to know more. Found out here at BritBike on the Serial Number pages that it means Clubman. Were A65 Lightning Clubmans only produced for one year? The left case has a casting number 70-0999 The case has the trans and cam. More questions: 1) The serial number script varies. Bogus? 2) The casting number on the left case is 70-099. Bogus confirmed?
Different views and takes on this stuff by various people but iv'e always thought that what made any of these old crates rare or different was what tuners and blokes did with the standard factory turned out mostly junk of the day, not what bloody number was stamped on the cases. All the cases were the same over all the models anyway, it's not as if the spitfire had special strengthened features or the lightning clubman had facility for fuel injection, they were the same as the others with the exception of the head and/or gearbox cluster, maybe a set of pistons and carbs. All the stuff was available for anyone to bolt on if they wanted.
The C indicates 1969 model year. For that year BSA used a new typeface for stamping all engines (as well as all Triumph triple engines as they were made at Small Heath). And serial #s were on the raised pad as on your cases though the pad did change a couple of times during the 1970 model production.
Oddly they didn't use the same typeface on frames as far as I can recall.
This looks like a replacement crankcase (the 70-9099 is legit as is the serial # pad). When I worked in the Brit bike business (in Texas USA) the area service manager would bring stamps & stamp replacement cases with new #s. This looks like the case here as a few are not correct: 5,6, 8 & possibly A. The others look correct. Maybe whoever stamped it lost part of the set & used others. Then it may have come off the line this way. The 5,6, & 8 may have been lost or swapped for a beer.
Frankly, I'd take it as a novelty & not worry about it.
As an aside I have read in several places that BSA stamped completed engines then later stamped frames to match. Maybe. In the video Bits Stuck Anywhere there is a clip of the Triple assembly line. One worker is stamping the engine #s at the end of the line. Perhaps he was trying to correct a badly stamped #. I have seen one serial number with a 4 stamped over with a 1 to match the frame.
When T160s were on the market I had to replace a few crankcases. The last time I saw the SM he came to stamp some replacement cases. He left his stamps at the shop. Only a few days later NVT announced liquidation & I never saw the fellow again. Over the years I lost most of the set. I can stamp any serial # as long as it uses B, L, T, 1, 2, 0 only.
There are a number of serial number lists that claim Lightning Clubman’s were built in 1966 and used the A65LC engine code. I have researched that model a lot, IMO any bikes dispatched in the 66 model year as Lightning Clubman’s were left over bikes.
There were 190 Lightning Clubman’s built in 64/65 using A65DC engine code. Allegedly, 29 more were assembled in 66 model year. Note that A65DC does not clearly define a Lightning Clubman. Any road model dual carb 650 twin of 64/65 model years with a close ratio gearbox got that engine code. The close ratio gear set was available in 66 and those engines would have been stamped LC. The odd Spitfire Hornet cases from 64/65 show up stamped EC as well.
I believe those number stampings could very well be original factory work.
I have a fairly large collection of engine number stamping images from multiple years. All manner of letter and number fonts were used at the factory and in different combinations. Here is a sample of an "8" being of a different font than the rest.
Ok, I've been convinced to set aside my adult beverage, go to the garage to investigate. I have A65s from 67~72 as well as many frames & crankcases. I do have a complete '69 whose provenance I know. That one is A65TCnnnnn. It uses the old stamps as do other '69 crankcases.
The old stamps used a larger 8 as a rule, so the OP's #s may be 100% legitimate.
The A65x/MYnnnnnn scheme was introduced in 1970 as far as I can tell. All '69s are A65xCnnnnn. Of course this brings us to '70 where it may be A65x/MYnnnnn or a '67 serial # with -Y.
Then in '71 some where MYnnnnnA65x OR A65x/MYnnnnn.
I think that I'll go back to my AB before I think about this more.
I had a particular interest in 1969 year stamps at one stage. My early 69 A65F has some different fonts to that. But sits about 3000 down the number series and the order of the individual elements has changed to the later style format with the letters indicating month & year and the model last. Bacon's books state numbering system changed during 1969. I know he gets things wrong but mine is consistent with that.
I found 2 others with the A65LC XXXXX format. Some similarities noted. Interestingly these all sit in the 11xxx number range. Looks like its anything goes on the stamp fonts. That 8 looks consistent though.
I'd say my bike has genuine numbers. The others look OK to me.
From a purely practical point of view, the later the cases. the better they are. Like most motors that have been in production for several years, various developments are included into the later ones and certainly with the A65, there were several improvements and the strengthening of the cases generally. If the machine is going to be used as a motorbike rather than an exhibit, then the latest cases were better.
>"...I believe spitfire (maybe only mk2/3??) engines had the little piled arms stamp near the number, just like the one on the GP carbs. Though I don’t know if they did this on clubman motors. AIUI it was something that was done to signify motors being assembled in the competition shop. Maybe Gary could confirm?"
That little stamp was typical on multiple models. I know of no information to indicate it was anything special.
They may have been some LC cases in 66, though the C would always have meant close ratio and clubman.
I think the 'C' was intended to indicate the close ratio gear cluster. The Lightning Clubman would have come with the CR gear cluster, so being stamped LC may just be a happy coincidence.
I’ve actually Amended my text to “not clubman”(I should proof read before clicking post)
A bit like the DC casings, all clubmans (least from 65) had DC motors, but not all DC motors went into Lightning clubmans.
Bikes with close ratio boxes could be ordered (or at least in theory) right until the end, however whether the factory continued to stamp the engines accordingly is beyond me.
I believe spitfire (maybe only mk2/3??) engines had the little piled arms stamp near the number, just like the one on the GP carbs. Though I don’t know if they did this on clubman motors. AIUI it was something that was done to signify motors being assembled in the competition shop. Maybe Gary could confirm?
The casting surface is as original behind the stamps, so regardless of when it was stamped ie at the factory or at a dealer the current numbers are the first numbers stamped. So very extremely unlikely to have be parted out from a stolen bike and then restamped.
After filing the area flat, use some coarse emery and hammer it onto the surface, you wouldn't be able to tell the difference between that and the original finish. You may have to scrub the area with dirty kero and wire brush etc. Then just stamp whatever number you want, don't be too neat as the factory wasn't and don't hold the stamps too square or it'll look too good. OR just run a weld across the number and say the case was cracked. If it was a Brough i may worry but these things were mass produced like sausages, who cares?
Yes but I was not going to mention that . Plus it does need some skill and technique to do it properly or it just looks too uniform.