Gran sport piston in DR 177cylinder help needed

Hello from new Zealand

will the gran sport piston (sold for polini and dr177) work in the  DR177 cylinder without any modifications other than a rebore to 4thou clearance?

the dr piston is no good now so I purchased a gran sprot piston which will be stronger

the boost arrangement of the DR is quite different from the GS piston. Dr has the three vertical thin windows.and one horizontal window and also two holes high up on the piston .... the GS just has one window down quite low

will the GS piston work ok in the DR 177 cylinder without any modifications???



I put the GS [piston in with no modifications at all..none..nada.zilch.....and it ROCKS.... 24 delly..sip road pipe

home cut crank (15mm of leading face)

Hey shaneo,

here we have the Grand Sport piston for the DR177 Zylinder:

You´re right with the diffrent pistonlayouts.

The best way for a good result is a windowmodification on the piston.

Please check the cylinderlayout and customize your piston.