Nissan RB Oil Pump Crank Collar SpecificationsUnfortunately Nissan RB engines suffer from a design fault with the oil pump crank. Too short the flat part of the stock crank shaft wears prematurely and eventually spins without making contact causing rapid drops in oil pressure which are often fatal for your engine.This problem can be solved thanks to this piece of forged aluminium created and CNC'd by SuperForma in England : often called crank collar ultra rigid and remaining perfectly in place in the oil pump gearing for ultimate reliability. Comes with instruction manual in English as well as all required fitting accessories (crank shaft will need some modification for installation).