compression on a 16v with s2 pistons?

[Chris-White]

hi,
anyone know how low using forged audi s2 pistons (that on a standard audi engine give a CR or 8.1:1 ) the compression ratio will be dropped on an ABF or 9A engine? Also, if they are 81.5mm bore (+0.5mm overbore on standard s2), will the bolck need reboring to compensate?

Thanks.

(p.s, guess what im collecting parts for  )

[danny_p]

s2 pistons will give no compression in a 9A or ABF    as they are 82.5mm bore standard

in a KR or any other 81mm bore block with a 16v head they will give the same cr as in the audi engine

if you have oversize pistons the block will need the apropeate rebore to take them else they wont fit