This is our newest ultimate performance WR 42/36 Big Valve Kit designed specifically for the OEM 356/912 cylinder head.   It is a complete set of all components necessary to modify your stock heads for use with our 91mm piston and cylinder set. It can also be used in preparing stock bore heads for high rpm street or racing. 

The 8mm stem intake and exhaust valves are both custom made for us by Manley and are designed to take the added heat and abuse of an air-cooled engine.

The single groove locks are far superior to the three groove oem type, and eliminate wear at the retainer.

The matching steel valve seats are made for unleaded fuel and require a minimum of machine work.

The valves are designed to run hardened 2mm lash caps which provide a larger contact area for the rocker, and are sized to provide the correct length insuring proper rocker geometry and full valve lift.

The special WR Locking Valve Guides use a Viton intake seal and have a special ridge that is counter-bored into the head and held in place by the 4340 chromoly spring pad to lock the guide into place and center the inner valve spring.

The WR Dual Springs can be set up for a variety of cams from .325” to over .500” lift and are good for over 7000 rpm.

The WR Chromoly Retainers are specially designed for our dual springs and provide light weight and super long life.

These are not marginal quality Chinese parts! Everything is made in the USA. We didn’t just pull these parts off the shelf. They have been designed and tested in dozens of engines and fine-tuned and proven to work properly. Don’t experiment…use the best!  You can’t buy a better combination for your 356 or 912 engine.

COMPLETE KIT INCLUDES:

4 - 42mm Stainless Manley intake valves and lash caps

4 - 36mm Stainless Manley exhaust valves and lash caps

4 - WR Locking Intake Guides with Viton seals.

4 - WR Locking Exhaust Guides.

8 - WR High Performance Dual Springs.

8 - WR Chromoly Spring Pads.

8 - WR Chromoly Retainers.

16 - Manley single bead valve locks.

4 - 42mm hardened steel intake seats

4 - 36mm hardened steel exhaust seats.

Complete instructions for set up of valve tip height, spring pressure, and suggested porting and chamber modification.

Valve guides available in .555, .556.