Made in a hyper eutectic alloy with a high silicon content to provide tight cylinder clearances and quiet running characteristics, manufactured by a world class piston manufacturers specification" uses an optimised crown and dish (9cc) shape for improved swirl/burn. The A-series always gives better performance with a larger piston dish and smaller chamber volume. It also means that an otherwise standard 1275 cylinder head and engine block the bore size increase can be used initially where required as there is no big problems with compression ratio. "These are totally different to the original Evolution piston stocked pre march 2011". Pistons come complete with NPR top quality steel 1.2mm rings, with a 3 piece oil control ring-brown compression ring at top and all are marked TOP for correct side up fitting-instructions enclosed as rings require fitting.
Ringset for these is C-STN96
Sold singly, 4 required for engine set