1275 A series piston size?

[meverett]

Hi all,
Need to install new piston rings whilst rebuilding my 1275 engine.
The identifying markings are on the top of the piston as in the photo but not sure what size they are for ordering new. Any ideas?

IMG_3820.JPG

[meverett]

Re: 1275 A series piston size?

IMG_3822.JPG

[meverett]

Re: 1275 A series piston size?

I think these are standard as the piston diameter is 2.7805" and all the shells have been standard size.

[stevejgreen]

Re: 1275 A series piston size?

I would suggest talking to any of the Classic Mini parts suppliers. I am no 1.3 expert but I think there are only three or four piston variants that have a different grudgeon pin to crown dimension for a 1275.

I also believe that the piston rings for the 20142 pistons you show are NLA so you might be into buying new pistons and rings. Not so bad as you can do a little tuning in the process of the rebuild.

Good luck, keep us posted.

[meverett]

Re: 1275 A series piston size?

Thanks Steve,
If i purchased new pistons and rings what are my options, would any standard size 1275 fit or am I restricted by gudgeon pin size and therefore have to fit new con rods.
It is a shame as it's only one of the oil rings that is damaged, somehow got a nick in it during storage, they were all fine when removed and the bores are all good.

[stevejgreen]

Re: 1275 A series piston size?

As I said, I am no expert!
I have a little experience of 1.3/1275 engines from days gone by. The experts will be the Classic Mini guys who will have seen so much more than me, but I am sure that there is a limited supply of the many possible piston variants, and that piston rings are a critical factor, old rings do not fit new pistons and vice versa.

New, accurate information is always useful. I am mostly in Spain, you UK guys have to do your own research and discovery.

[listerjp2]

Re: 1275 A series piston size?

I have pm'd you

adrian

[stevejgreen]

Re: 1275 A series piston size?

I have pm'd you

adrian

Do you have specific information that will help others, or is it confidential?
Can't see why it would be restricted to a PM?

[meverett]

Re: 1275 A series piston size?

After a bit of research I can replace these for the 21251 pistons which are low compression or go for the higher compression pistons 21253. Both available at minispares.com
Fair difference in price the 21251 are £132 for 4, the 21253 are £194 for 4.
Any 1275 A series gurus out there could tell me which ones are the closest to my removed 20142 pistons?

[dogoncrazy]

Re: 1275 A series piston size?

I rebuilt my 1275 with Mg Metro pistons which had a higher compression than standard. This was on a A + engine so may have been different in terms of gudgeon pin , which was if I remember correctly a press fit and was done at engineering shop.