ZRP-C-MIN-002 - The ZRP crankshaft for Mini Cooper S R56 is manufactured from aerospace grade 4340 solid billet steel and no compromises have been made to the quality of the material, in order to ensure the best possible product. This crankshaft designed carefully from our vast experience, to provide the best possible engine performance and the production process consist of very strict inspections to ensure that they have the best quality and tight tolerances for perfect fitment. The Mini Cooper crankshaft is fully balanced to 1gr.cm /- 0.1 using state of the art Sunnen machines, balance results report included. Check the individual features for your application below. Product Features and Design Undercut profiled counterweights to minimize weight and reduce rotating mass. Straight oil holes for better oiling of the rod journals. Chamfered oil holes Journal radius disperse load stress. Tapered rod journals for weight reduction. Technical Features of ZRP Crankshafts Full CNC machining. ION (Plasma) Nitride process for hardening. Multi Stage Heat Treatment. Shot peening for stress release. 100% Magna- fluxing for flawless surface finish. Heat treatment for superior wear resistance. Micro-polishing for longer bearing life. Sonic tested and X-rayed to ensure a reliable end product.