Does anyone know the standard bore size of a Civic Type R piston?

 

Well I am gonna have to go with 81.00mm with it also being offered in 81.25mm.

 

standard bore is 81.00 on all b16a/b/b17a/b18a/b/c engines

 

If you plan on purchasing these are placing them in a B-series motor you might as well buy the oversized ones. You would have to have the block honed anyways. Little extra comp. and displacement (usually ) never hurts.