14 replies to this topic

[babyrich82]

21963 n39 a

These are the numbers printed on my pistons, they look in great condition, however can anyone help me identify them better please, I.e. The performance of the engine when they are installed???

Any help much appreciated.

Cheers
Rich

[babyrich82]

Picture of piston number

Attached Files

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[babyrich82]

21963 G7 n39 a

to be exact

[babyrich82]

Anyone???

[Dan]

I *think* it's a +20 1275 Rover piston. The first standard over bore.

[babyrich82]

So would it wouldn't be a 1275 anymore?

[Dan]

Not quite! 1293.

[Cooperman]

I think it is a standard Mini/Metro 1275 piston at normal bore. A 1293 piston would have +0.020" stamped onto it.

[babyrich82]

Why is it dished then?

[ACDodd]

These are stock factory 1275 pistons fitted to either the later MG Metro engines or the cooper/spi and mpi engines. Basically any engine the factory needed 10.1:1 compression in these were fitted.

Ac

[babyrich82]

Hi AC thanks for your reply, are they any good? They have cleaned up really well with carbon remover, I don't really want to do anything to the engine bar possibly supercharge it.

[ACDodd]

What is the top ring side groove clearance?

Ac

[babyrich82]

No idea at the moment pistons are still in the block

[Dan]

  Apologies, I could only find a +20 listed under that number and the equivalent +40 seemed to have a completely different number so I assumed wrongly that they had unique numbers in the series.  I thought it was odd it wasn't stamped +20.

[babyrich82]

Cheers