[Adrian II]

Is this with a view to obtaining a UK age-related registration number, Dan?

A.

[grumbern]

So with the frame number Graham Scarth should be able to tell you the engine number. You can easily check, if the numbers you see would be identical and just add the rest with punch numbers.

[Citrus]

I also have a 1934 LF. engine Number LF 1595 that left the factory on 19 Sept 34
Your engine number will start with LF but be different to your frame number
Graham Scarth will not tell you what the engine number is - even though he will have that data - specifically so that people can not "make" matching number bikes. If you tell him the number - he will tell you if it is correct or not.

[Ove]

I've heard there are more Bugattis surviving today than the factory built....  of course, that's what put me off!

I'm surprised if there is no sign of an engine number. It doesn't seem plausable that previous owners managed to 'accidentally' polish all trace away.  Do you need the engine number to register / tax the bike? If not, leave it as an intriguing unsolved mystery and enjoy working on it and riding it.

I've got an old 50s sports car. It is registered on it's body no. not the total chassis no. 'Lost' its chassis plate in its first few years. Been that way since it was re-imported and UK registered  in 1962. I'm fine with that and it hasn't caused any legal or practical problems, like getting the right parts for it. Nice talking point.

[grumbern]

It's the same with Ford model-As and hardtail Harleys... And there's a whole lot of Bullets for sale from the "mid-60's", that don't look old at all.

[Ove]

Only their owners do...

[Anonizator]

Hm.. This polish looks very strange. Apparently, he did it on his own without professional equipment. Well, back to restoring the engine code-chemical etch is probably one of the most effective solutions to this problem, so maybe it will help you, but I'm not 100% sure about it. If you have friends who can do this for you at a discount, then you should use this service. The main thing is not to try to search for this number on the Internet, as I am sure that you will not be able to find anything about your engine. When I was looking for information about my engine, I came across a site like https://www.sunsigns.org/angel-number-55-meaning/ and now I'm addicted to numerology. By the way, I did not find any information about my engine

[ddavidv]

The last Bullet I worked on suffered from over zealous case polishing. A few of the digits were barely readable. The bike was once a crusty mess so it's not necessarily done to hide anything.

[muezler]

I dont think that PT (Dye penetrant testing) would lead to any feasible result.
There are too many micro and macro scratches from damages and from the previous "Polishing" processes.
As soon as you put on the developer all the residues from the other scratches will start to bleed into each other and you would not see anything besides a big blob of red.
Plus you will make a bloody mess out of your garage...quite literally a bloody mess.

My best bet would be to uninstall that part and make a RT (x-ray or gamma ray test)...if the numbers were hammered in with enough force, then you should see differences in the material density where the chisel was used.

If you have a steel structure or plate work workshop next to you then they should know someone who is doing the NDT (weld testing) for them.

But this might be a bit overkill for just getting an engine number

Cheers
muezler

[Karl Fenn]

Well this is where my forensics come in, apparently painting it in acid will show the number, they use this technique to trace stolen BMW when they have ground the number out, when they punch the number it leaves an impression deep into the metal, not sure which acid they use

[mountainrider]

Hm.. This polish looks very strange. Apparently, he did it on his own without professional equipment. Well, back to restoring the engine code-chemical etch is probably one of the most effective solutions to this problem, so maybe it will help you, but I'm not 100% sure about it. If you have friends who can do this for you at a discount, then you should use this service. The main thing is not to try to search for this number on the Internet, as I am sure that you will not be able to find anything about your engine. When I was looking for information about my engine, I came across a site like https://chi-nese.com/565-angel-number-spiritual-meaning-love-money-twin-flame/ and now I'm addicted to numerology. By the way, I did not find any information about my engine

What do you mean by "not to try to search on the internet?" The internet is the only place people can find answers! I recently tried to recover my old engine number, and if I did not find this forum and youtube, I would never have been able to recover the number.