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 manufacturer to "MAR Motorsport 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 2012.
Top ring is 1.15mm, Chrome face Second ring is also 1.15mm height Oil Rings are 4mm