Which 12a497 casting style for 997 block?

[Cole Liggett]

I know that there were two different casting styles for the 12A497 blocks. I’m trying to figure out which casting style the 997 Cooper would have had.

12A497

Or

12A
497


I’ll attach photos for reference and I appreciate the help in advance!

[Dearg1275]

To make it more interesting /confusing there were three variations in 997 blocks and again three for 998. Of course the part numbers for the stripped blocks bare no relation to the casting numbers (all start 8G the same as standard minis) and the numbering is all over the place. The 997 (&998) had an early and later high compression block and later (115142 on) a LC block. I can only think that the deck height was increased on these LC offerings. The 998 engines used all three variants of their block from the start (101 on).

The casting style may not reflect any of the above but reflect which foundry produced them.

CF237E63-4889-44CD-9DB7-E9E1A07E5DF8.jpeg

D

[Spider]

I'm pretty sure they are one and the same in every material way.

The 'difference' here is the foundries they were cast in and I'm 99% sure, that's all.

[Dearg1275]

The block with the W mark is a Wellingborough foundry casting. The other has markings RMO that are of identical font and size to the WMO cast on my early 12A204, 997 block. The other major foundry was I think in Coventry.

D

[wild_willy]

My 12A497 cooper 997 block has no fuel pump provision (hole not cast). My 12A497 Cooper 998 block has a hole for the fuel pump albeit covered with a blanking plate from original.

[Cole Liggett]

This makes more sense, thank you everyone for the information!

[251 ENG]

The wellingborough marked casting would probably be most suited. They supplied the castings for all the specialist engines such as formula junior and cooper s , all were built at Morris Engines in Coventry.
I would think that all the 997 engines also came from the same source .
As long as it's a thin flange block it should be ok .

There was an original late 997 block for sale on here about 6 months ago but I can,t remember which block casting it was

[Dearg1275]

The wellingborough marked casting would probably be most suited. They supplied the castings for all the specialist engines such as formula junior and cooper s , all were built at Morris Engines in Coventry.
I would think that all the 997 engines also came from the same source .
As long as it's a thin flange block it should be ok .

There was an original late 997 block for sale on here about 6 months ago but I can,t remember which block casting it was

Not so. As above, my 12A204 early 997 block does not have the Wellingborough logo. Something else to start recording in your wee book of numbers perhaps?

D

[251 ENG]

That's interesting David

What foundary mark does it have ?

[Dearg1275]

Simon. This is all there is.

995EC208-A903-4BF0-981E-6C87719EB190.jpeg

Does it tell you anything?

D

[251 ENG]

Somebody, somewhere will have a database of foundary marks

[JohnA]

Very early casting from my 997 project. No.12 i believe.
Has fuel pump hole.

[GTOGREEN1969]

Great info. Thanks