- The piston is 87mm, which happens to be 1mm much larger when compared to the normal 86mm, and the material is light-weight and powerful A4032 forged aluminum alloy. The required clearance of 0. While this isn’t a lot of an engine flaw up to it is a style flaw, https://nissanskylinerb2677655.blogdosaga.com/28153860/nissan-rb26-engine-an-overview