Description Reviews Supertech MINI Cooper N18 Intake Valves ONLY. The correct valve can make or break an engine build just like the correct piston. This set will build your motor to be built proof! Std or over sizes set of 16 with keepers. Make sure you pair it with all of the other Supertech items like the, valve springs, valve seals, and valve guides! Need just 1 valve as a replacement? Give us a call. Stock: Black Nitrided Intake Valve MCIVN-1301S Head Diam: 29.80mm Stem Diam: 4.96mm Length: 95mm Material: Stainless Steel 21-4N Comment: Single groove Valve Type: Intake