Description Reviews USED set of Pistons and Rods for they W11 R53 motor. VERY Low Miles, Spun a ring at break in, Sent the motor back to get fixed. Spun another ring about 150 miles later. we then bought they customer a replacement MINI create engine to get they car running reliably. im sure they correct machine shop can over size things and clean things up to work correctly. The rings don't even have many miles on them. Maybe you have another project in mind, go for it! We are just trying to recoup some costs spent. No warranty, guarantees, or returns. Per RMW's web site: These are our race version and come with our custom Cometic head gasket. Simply the best designed piston/rod combo out there. Proven to over 600whp without issues. RMW Mahle pistons are available in size from 77.5mm and 8.5:1 compression ratio. We have worked extensively with Mahle Motorsports to design something special. Our designs will fit flush in the bore around the outer ring to give better quench and the unique center dome helps "stir" the mixture for better power and torque. Anodized ring lands to give greater strength and gas ported. Find something with these features at this price. (You won't find them because we are the only Mini Company out there stocking them) We use Mahle Motorsport custom rings for low oil consumption. These pistons have the tightest bore clearance on the market at .0015" and will be quieter than all of our competitors pistons. Mahle's Grafal coating on the side skirts just like the factory pistons. This is another first in the Mini community. These are for force inducted engines. You can rest assured if we sell it, it's already been tested in our own cars! Many sell parts but have NEVER actually TESTED them to see if they work. Strange ,don't you think? That will never happen at RMW. The most advanced piston for the Mini Cooper