Mine is:

XNFAD18Y/102918 - July 78.
The engine number is 12H87UH002232

_________________
Cheers
Alec
1275LS - July 78 - XNFAD18Y/102918

Is everyone saying that this is an 1100 not a 1275? If so you cannot blame the buyer for being slightly disappointed that it was advertised on the forums as a complete, genuine and original LS with 1275, not only by the last owner, but also backed up and posted by poeee, yet it appears that this is not the case at all. I would have though such things were verified before it was put up for sale, and such claims were verified genuine....

I'm am not trying to get anyone's nose out of joint, but if both the last owner and poeee both claim its a genuine 1275 LS, one would think that its a valid, credible source of information.


Just my 2c.


I am of coarse referring to the below which is the text from the sale thread:

No, the motor is from a Morris 1100S, not a Mini.. it's a 1275, just not a genuine LS. It's still a good motor, just not original.

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Simon

The adventures of an owner builder in the Tallarook Ranges

Ahhh right.

That makes sense then. But its still not "genuine" as claimed right?

I'd consider it a "genuine" car myself.. but obviously not "matching numbers".. but then it wasn't advertised as such.

_________________
Simon

The adventures of an owner builder in the Tallarook Ranges

Can anyone categorically state that the motor isn't the original. If the Vins are reliable and the engines could be numbered out of sequence is it not possible that the early cars used whatever 1275's they received until the 12H902U's arrived?? My case in point is the few 12H897U's that have turned up and this 12YTAH....

_________________
Cheers
Alec
1275LS - July 78 - XNFAD18Y/102918

There were actually two sets of different numbers used for the 1275 LS - just to make things easy for all of us!!

It appears the 'earlier' models had the body prefix of 022X2S4M09 and it should be fitted with an engine having a prefix 12H897/U.

The 'latter' models had the body prefix XNFAD18Y and should be fitted with an engine 12H902/U.

I'm trying to establish when the number system changed, but it appears it was around September 1978 - perhaps someone could shed a bit of light on this.

Interesting also is that (at least some) of the factory information says that production of the 1275 LS didn't commence until August 1978 - now there's an eye opener for you guys with the July Plated models

The 12H/389/SH engine is from an english 1275 GT.

There is a lot of myths about prefixes around. Nearly every list I have seen has a lot of mistakes and these mistakes keep getting passed along.
The prefix 022X2S4M09 is for a 998 LS not a 1275. See the 09 on the end of the prefix? that stands for 998cc.
As far as I know all 1275LS's were made after the change in code to the new type (the bulletin for the change of code was dated 24 April 1978). So they should all have the XNFAD18Y code.



The 12YD/Ta/H prefix is a Morris 1100S prefix. There is no possibility of a Morris 1100S motor being fitted to a 1275LS from the factory. It just didn't happen. It was 9 years later and the two motors are very different in spec.

Yes, the 09 is supposted to mean that it is a 998, however I've worked on way too many factory genuine 1275 LS's with the 022X2S4M09 body prefixes for there to be a coincidence. I did thoughly check these cars as I thought the same, and either they are real or a lot of people have gone to a lot of trouble.

Over the years I have come across a lot of factory 'funnies' and reading other peoples experiences and noted discrepancies it is pretty obvious that despite the good system of coding that the factory developed and all the unique parts for particular models, the reality of what happen on the production floor is quite different to all this. One clear example of his that we all know of is the latter Cooper S's, from around 1969 - I doubt that any two that rolled off the line where the same and none of them 'line up' with the parts books.....

All the 1275LS's were built after the code system changed. There is no chance of a 1275LS wearing a plate with the 022X2S4M09 prefix. That system was finished at the end of April and the 1275LS came months later. There was no going back.
Any car with a 022X2S4M09 prefix would be a 998LS, even if someone fitted a 1275 motor later.

As for the rolling changes through the life of the Cooper S I don't think that there are any great mysteries in them. They introduced changes as old parts run out and new parts were developed. They didn't build one with a Lockheed booster and the next with a PBR and then go back to a Lockheed. They just made a change and moved on. There are no secrets left unsolved.
We know the approximate date of each change in the production run of the Cooper S.

Hi All,

Thanks for the info, my apologies if i sparked a debate.

A question, just out of interest, if i have an 1100S, what is the difference between a 1275 and what i have? Would the current motor i have still be worth a re-build, or would the output be significantly less? I know this question is probably in the wrong thread now...

Cheers,

Jimbo

The motors are nearly the same. After this time the main difference will be the stamping of the engine number.
If you rebuild the motor there will be no difference between the output of the two engines.
Most modified cars use the motor out of the Morris 1100S as there are more of them around.
They made 1000 1275LS's.
They made over 15,000 Morris 1100S's.
You can see why so many cars have the wrong motor.

Ok. What I'd like to know is this:

Mine has an engine that is 12H897U (but with the 9 missing thanks Leyland ).

I can see no other minis that use this number on the lists other than the suggestion that some other 1275LS's had them. So what does the 897 mean compared to the 902 and how does anyone out there know for sure that 12H902 was the only code on 1275LS?

If someone has the magic book of Vin/engine numbers, where do I get my copy?

_________________
Cheers
Alec
1275LS - July 78 - XNFAD18Y/102918

Refer my posting 3 up.

PS I never said they went 'back and forth' with parts, only that there were a lot of differences in the same model.

Hi All,

Just an FYI (since I feel responsible for starting the LS1275 engine side discussion).

I sourced my 12H902 engine block today. Got it for just over $200.

Now, onto the original resto......

Thanks for everyones advice and input. Cheers.

Jimbo.