MGB Register Forum

Hi All

I've got a 1974 MGB GT that I'm trying to get back on the road. It came to me with no history (and a lot of rust) having been off the road for 20+ years. Its got a few of the usual upgrades but without any paperwork I don't know much about the engine.

Chief mystery is that on the V5 the engine number is stated as just "2825"
Clearly this isn't the original number. I presume its either a mistake at the DVLA or a previous owner had a recon / uprated engine fitted that came from a company that gave their units their own numbers. If thats the case, hopefully I can track down the supplier and see if there is anything interesting about the spec.

So, my question is: Does anyone know of a supplier that renumbers their rebuilt engines with a 4-digit number?

Many thanks and Happy New Year
Peter

ps - its Citron Yellow and no, I'm not going to change the colour :¬)

Hi Peter,
Welcome to the MGB Register Forum

Is that the only number on the engine itself?

I know there are lots of cars on the register with just digits & it's a guess but that would be the numbers after the important letters.

Happy New Year

Paul

Just to be clear: the engine number should be on an aluminium tag mounted on the block next to the thermostat housing.
These tags do often get removed if the engine is rebuilt, but there is no real reason for ever removing that tag.

Yours may be something like this: 18V 847F H 40101)

Ian F

Happy New Year

Sadly no tag on the engine. I'd like to add one but want to try to confirm if the 4 digit number recorded on the V5 is actually correct or not first.
There is a good engineering company in Didcot that would probably do the stamping. I cant find a supplier for them online.

From what I've researched so far I think the original would be something like 18V 780F H ##### but I'll order a heritage certificate to find out for sure.
I guess the 4 digits recorded could be the last group from the plate but I'd have thought they'd be higher numbers in 1974.

I have looked at the Register all of the chassis no's around Peters chassis number there are a few within + - 10 and these are prefixed 18V780FH 28**
Paul

I sent you a private message yesterday Peter.
When you are logged in or you may have had an email to advise a message has been sent.

Here is mine 75B located around the dipstick area on the block

Paul

https://www.minisport.com/lmg1053s-a-se ... umber.html

You should be able to get an authentic replacement plate from these people.

Ian F

Thanks
That looks good

Ian F wrote: Thu Jan 01, 2026 10:50 am https://www.minisport.com/lmg1053s-a-se ... umber.html

You should be able to get an authentic replacement plate from these people.

Ian F

Is there any benefit in advising the DVLA of a change of engine number ?

Many years ago I remember having to trailer a car to a VOSA site for inspection as I was trying to sell it's registration number but it didnt at the time have a current MOT. (I was selling its reg number to raise money to repair the rest of the car).
The inspector commented in passing the engine number didnt align to the V5. I was worried this might derail the process but as soon as I explained the old engine was dead when i first got the car so I had changed it during my ownership, he nodded and asked if I'd like the change of engine number recorded whilst they were doing the registration change. They couldnt have been more helpful.

Not sure if things have changed since but the engine number didnt seem of any great importance to them.

There is a lot of inconsistency when it comes to engine numbers, which I guess proves your point that the authorities are generally unconcerned.

A few observations:

# many vehicles do not have the engine number recorded in the BMHT records, or on the V5. This is true for many older Land Rovers.

# I suspect that most MGs pre 1980 will have had an engine rebuild or swap, and that a large number will not have the correct engine number on the V5. When A series engines have their block refaced then this will inevitably remove the engine number tag which sits flat on the block face. Very many will never be replaced.

# I have been involved in club level motorbike racing for many years, and a few years ago the club's tried to get a real grip on frame numbers and engine numbers, to the extent that you could be excluded from a meeting if they weren't present. This was presumably driven by the authorities.
Race bikes are not road registered generally and many have no V5, and it was widely acknowledged that these bikes provided a good outlet for stolen frames and engines with the stamped on numbers removed.
The same considerations could apply to older classic cars with engines which bear no engine tag, and which have no receipt for a replacement engine.
I believe this area of engine identification and proof of purchase will be addressed in the forthcoming vehicle registration regulations.

Ian F