Hi folks, this year has been one with minimal progress on old bikes. Hopefully that will change soon and I will post more on what I have been upto when I get the 20F thread moving again however in preparation I have a question about clearance for piston rings in their ring grooves.

I have new cast iron pistons and am using cast iron rings all inside cast iron cylinders. At the moment the rings have 0.001" clearance in the groove but that isn't necessarily the final figure. I have read lots about clearance when using aluminium pistons which all say more clearance is needed which makes sense for the dis-similar metals but I cant find anything about cast iron pistons. Therefore I was wondering what the experience on here is?

Thanks in advance