Author Topic: Recovering an old engine number (Read 6508 times)

Dantheman · **on:** January 14, 2020, 03:50:25 pm

Does anyone have any tips for trying to recover an old engine number stamped into a set of crankcases?

I have an early 1930's 4 valve Bullet (Model LF), a previous owner has excessively polished the crankcases and the engine number is no longer readable other than the first two letters. I have been looking particularly at a chemical etch, has anyone had much success with this before?

Adrian II · **Reply #1 on:** January 14, 2020, 08:42:57 pm

Know any good forensic scientists? UV light?

A.

Boxerman · **Reply #2 on:** January 15, 2020, 07:52:52 am

We used ro use a crack locating spray where I worked, to locate finer - than - hairline cracks in hydraulic components.
It was a 3 part process, primer, spray & developer and would show up cracks not normally visible to the naked eye.
Not sure if this would work for your case, but it is all I can think of.

Frank

Ove · **Reply #3 on:** January 15, 2020, 07:07:29 pm

How about a high resolution digital camera, zoomed up on your screen? Some phone cameras are at high mPs resolution. Play around with lighting angle?

Kevin Mahoney · **Reply #4 on:** January 15, 2020, 08:37:58 pm

you might want to try Baxter Cycle in Marne Iowa. They deal with this stuff everyday

olhogrider · **Reply #5 on:** January 15, 2020, 09:26:21 pm

Quote from: Boxerman on January 15, 2020, 07:52:52 am

We used ro use a crack locating spray where I worked, to locate finer - than - hairline cracks in hydraulic components.
It was a 3 part process, primer, spray & developer and would show up cracks not normally visible to the naked eye.
Not sure if this would work for your case, but it is all I can think of.

Frank

What you are describing is "dye penetrant". It is like magnaflux for non-ferrous metals. Aircraft maintenance supply houses carry it.

Boxerman · **Reply #6 on:** January 15, 2020, 10:15:29 pm

This looks like the stuff we used:
https://www.gas-uk.co.uk/crack-detection-spray-set.html

Frank

grumbern · **Reply #7 on:** January 16, 2020, 03:07:37 pm

It is possible to recover even sanded VIN's by scanning the material with x-ray. This will uncover the indents in the inner structure, even if the surface is smooth. I know this is used for crime investigation, but I don't know if this technology is somehow available to a "civilian" in an affordable manner. Just an idea. Chemicals won't work, as these tend to work their way regardless of the fine irregularities in material structure.
Andreas

olhogrider · **Reply #8 on:** January 16, 2020, 09:37:21 pm

Quote from: grumbern on January 16, 2020, 03:07:37 pm

It is possible to recover even sanded VIN's by scanning the material with x-ray. This will uncover the indents in the inner structure, even if the surface is smooth. I know this is used for crime investigation, but I don't know if this technology is somehow available to a "civilian" in an affordable manner. Just an idea. Chemicals won't work, as these tend to work their way regardless of the fine irregularities in material structure.
Andreas

Some aircraft, Beech 18 for example, require the wing to be x-rayed. If you can find an aircraft shop that performs those inspections they could probably do you. For a price. I doubt if any doctor's office would do it.

Arizoni · **Reply #9 on:** January 17, 2020, 03:49:46 am

The equipment in a doctors office won't begin to penetrate metal if it has any thickness at all.

Dantheman · **Reply #10 on:** January 20, 2020, 05:16:19 pm

Interesting comments, certainly given a few more ideas, thanks

ERC · **Reply #11 on:** January 21, 2020, 09:58:59 pm

Find an old registration where it came from. That should have a number. Unless it hasn't been registered in a lot of years. ERC

Dantheman · **Reply #12 on:** January 22, 2020, 09:25:59 am

Quote from: ERC on January 21, 2020, 09:58:59 pm

Find an old registration where it came from. That should have a number. Unless it hasn't been registered in a lot of years. ERC

The story goes that the bike has been untouched for 50+ years in Germany before making it to me, and unfortunately has no registration or supporting paperwork. Its still a project bike in its current state and missing a few pieces.

grumbern · **Reply #13 on:** January 22, 2020, 05:35:51 pm

Did the engine come with a frame? Then the frame should give a clue to the engine number.

Dantheman · **Reply #14 on:** January 24, 2020, 05:18:14 pm

Quote from: grumbern on January 22, 2020, 05:35:51 pm

Did the engine come with a frame? Then the frame should give a clue to the engine number.

Yes, the engine is in a correct type 1934 frame which has been dated by the club (its about 90% of a bike), the engine is the correct 1934 type so stands a good chance they are paired from the factory, but it would just be nice to officially confirm this with the numbers through the owners club. The engine and frame number on these bikes would be unique to each other originally, as opposed to being identical like some other manufacturers.

Adrian II · **Reply #15 on:** January 24, 2020, 05:20:04 pm

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

A.

grumbern · **Reply #16 on:** January 24, 2020, 09:09:25 pm

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 · **Reply #17 on:** January 25, 2020, 02:29:54 am

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 · **Reply #18 on:** January 25, 2020, 09:52:20 am

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 · **Reply #19 on:** January 25, 2020, 03:04:05 pm

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 · **Reply #20 on:** January 25, 2020, 06:55:58 pm

Only their owners do...

Anonizator · **Reply #21 on:** February 17, 2021, 01:48:33 am

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 · **Reply #22 on:** February 17, 2021, 01:42:31 pm

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 · **Reply #23 on:** February 18, 2021, 10:00:12 am

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 · **Reply #24 on:** February 27, 2021, 09:08:09 pm

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 · **Reply #25 on:** January 09, 2023, 10:42:03 pm

Quote from: Anonizator on February 17, 2021, 01:48:33 am

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.