- The piston is 87mm, which happens to be 1mm larger sized compared to the normal 86mm, and the material is light-weight and robust A4032 solid aluminum alloy. The specified clearance of 0. Anyway… If a crank provides a 0.02mm runout, Meaning it will take up 0.01mm of oil clearance https://nissan-rb26-engine61592.elbloglibre.com/28192240/the-5-second-trick-for-nissan-skyline-rb26