Head Oil Drain Adapter Kit for Nissan RB Engines (V2) Specifications Developed by our partner MZR Garage this V2 kit for Nissan RB engines (RB20DE RB20DET RB25DE RB25DET RB26DETT) enables to fit an additional rear oil head drain. RBs are prone to the phenomenon of oil pooling in the cylinder head: at high revs all the oil is pumped up into the head this will cause the sump to be drained and the engine eventually will suffer oil surge which can have dramatic consequences. This kit provides an effective solution to this problem which is particularly common in drift and drag and requires you to thread the existing M6 hole for the M8 bolt to install the adapter. Kit contents: CNC head drain adapter with O-ring Dash 10 nipple Dash 10 plug Bolts