Bob , you are correct . That is a forged CP 102mm piston for a Yamaha Rhino 720 stroker engine . ( 660 ) . I have read that Yamaha does use a Nikasil coating on their cylinder bore surface but with boring that is now gone so iron would be the bore surface . I'm still trying to find information on the rings Falicon sent with the piston . Busy day again tomorrow and I will call Falicon directly , if time permits , to find the answer to your question . Thank you .

Did they offer a big bore cylinder from Millennium ? When you run the cast iron sleeve, the clearance is going to be greater than the aluminium that is nikasil plated, that defeats the purpose of the design of all the newer 4 stroke higher rpm single cylinder engines. What is the redline on that machine? Of course that's the X design piston from CP, which gives it strength. Did you increase the CR also. Does that cylinder head come with titanium valves as the YZ250F and the YZ450F do?

7800 rpm redline . Compression ratio is supposed to be 10.1 but may actually be a little higher according to Falicon . Crank is +4 mm over stock all forged and balanced . Stock cr is 9.1 . I bought all stainless valves , Kibble White double springs and Titanium retainers . Geez , I asked a general question about stuffing coated pistons dry and we end up building a Rhino stroker engine on the baddest Powerboating forum on the planet !! Just gotta love all the gearheads that hang here ! Just goes to show you we'll hotrod any dam thing ! Love this place and the intellects that hang here . Now , let's pretend that was a pic of a bbc coated piston and the question remains the same . Does advanced technology now allow us to stuff dry pistons into a new build ? http://www.jegs.com/p/Total-Seal/Tot...50299/10002/-1