6 replies to this topic

[MrIan]

I recently recovered my 1275 engine from a garage I rent. It was stripped many years ago and rebored but then left. On looking at the bores i'm thinking it might need another rebore to sort the surface out so what is the largest a 1275 block can be taken to ? I'll try honing the block bores firstly just to see (keeping fingers crossed).

I'm pretty sure it's already bored out by 30 thou and have a feeling 60 thou was the max years ago.

[gazza82]

60 thou unless you want to go offset (1330cc)

 

60 thou is also ideal as then you can re-sleeve to go back to 1275 in the future

[DomCr250]

73.5mm safely or 74mm if you are old school.

 

If it's just surface rust (no moisture has run down the bores) you may well find a hone will work well and you can run with what you have got.

 

The cheapish honing kits that run on a drill work well.

 

Dom

[MrIan]

Fingers crossed then I can shift it with honing as it's not been wet at all. If not it looks like I'm gonna have to hope another 30 thou will clear it. At least I have options to be able to save it then.

Edited by MrIan, 10 March 2015 - 09:27 PM.

[gazza82]

40 thou first ...

[Cooperman]

Always go to the next size up when re-boring engines on any classic car as there will never be any more blocks made, well affordable blocks anyway. Someone might cast some new 1275 Cooper 'S' blocks for many thousands of pounds each sometime in the future.

[MrIan]

Yes, I did mean I have got 30 thou to play with max. I'll try honing first but if no good then as you say 10 thou at a time to try n clear it.