7 replies to this topic

[ben.mini]

Hi All, 

 

Have stripped my engine down, and found the bores slightly lipped at the top, so looking at a rebore. I started looking at different pistons, but would like some views and recommendations for some good quality pistons. 

 

Engine is an MG Metro 1275 (bores are factory lined). I am looking to build a solid road engine, not really interested in changing the MG Cam at the moment, unless someone can persuade me other wise. Will also look at some head work in the future. So I am looking to build a robust short engine that can handle some light head modifications later.

 

In terms of pistons I have been looking at these from minispares:

 

Classic Mini P21253-20 - Mini Spares Onlne Shop

 

or these

 

C-STN100-20 - Mini 1275 +.020 mini spares evolution lightweight piston

 

 

Could anyone recommend them or is there something better on the market for similar money.

 

 

 

[nicklouse]

First thing I would do is get the block looked at by the company that will be doing the work. 
 

the bores need measuring to identify what bore it needs.  

[Spider]

I haven't tried them but the Mini Spares C-STN100's look a good unit.

[ACDodd]

The Evo pistons are very good with excellent rings, I recommend them.

Ac

[KTS]

..as above, no point buying +20thou pistons if the machine shop are going to tell you the bores are going to need at least +30thou.

 

Keith Calver also does a range of pistons for similar money

 

https://www.calverst...webshop/engine/

[ben.mini]

Thanks All,

 

I have measured the bores and got the measurements below. From these I think a +20 thou would be all that is needed. The wear is small, but from mic'ing the pistons the clearance is near 0.1mm (~4 thou) under the lip. So I figured a rebore would be needed.

 

 

[Northernpower]

..as above, no point buying +20thou pistons if the machine shop are going to tell you the bores are going to need at least +30thou.

Keith Calver also does a range of pistons for similar money

https://www.calverst...webshop/engine/

Keith's pistons are really good but they start at +40 for the 1275.

[Cooperman]

21253 has always been a good piston for most road Mini applications. Normally OK for up to around 95 bhp and 6500 rpm.