NRW Design Billet Valve Cover - BMW G20 M340i | G22 | G23 M440i | G42 M240i | G29 Z4 M40i (B58 Gen2)

The NRW Design B58 Gen2 Billet Valve Cover is a single-piece replacement for the factory plastic valve cover, developed over more than eighteen months of design, prototyping and testing. It removes the factory PCV system, a well-known failure point, and is designed to run with an external catch can system.

Three -12 ORB/AN ports provide efficient evacuation of crankcase pressure, which becomes increasingly important on high-boost builds and can help reduce valve train instability such as exhaust cam timing drift ("VANOS walk").

Please note: This item is supplied on a pre-order basis. The factory PCV system is removed, so an external catch can system is required – the catch can, hoses and lines are not included. Supplied with two -12AN swivel fittings, one -12 ORB/AN block-off fitting and one 1/8" NPT plug. The cover uses genuine BMW gaskets, which are available from any BMW parts supplier.

Features

• CNC machined from a single block of 6061-T6 aluminium to minimise leak paths
• Three -12 ORB/AN crankcase ventilation ports (third port allows future expansion)
• Internally blocks the factory PCV intake ports – no external plugs required and less carbon build-up on the intake valves
• Machined ignition coil dust seals to keep debris out of the spark plug wells
• Internal baffling for improved oil control at high RPM and high load
• Integrated 1/8" NPT port for a crankcase pressure sensor
• Compatible with BM3, MHD and standalone ECU crankcase pressure monitoring and fail-safe strategies
• Uses OEM BMW gaskets for easy long-term servicing
• Made in the USA

Fitment

• BMW G20 M340i (B58 Gen2)
• BMW G22 / G23 M440i (B58 Gen2)
• BMW G42 M240i (B58 Gen2)
• BMW G29 Z4 M40i (B58 Gen2)