9mm Exhaust Valve Guide - 2nd Oversize - Type 4 Engines

This 2nd oversize 9mm exhaust valve guide is designed for Volkswagen Type 4 cylinder heads that have been machined beyond first oversize or show excessive wear in the original valve guide bore. It is suitable for Type 4 1700cc, 1800cc, and 2000cc engines fitted to Baywindow Buses, as well as Type 25 (T3) Buses in both air-cooled and water-cooled configurations. It is also compatible with Porsche 914 Type 4 engines and selected Type 1 1600cc engines that use 9mm stem exhaust valves.

The exhaust valve guide is critical to correct engine operation. It precisely locates the exhaust valve, ensuring smooth movement, accurate seating, and efficient heat transfer from the valve into the cylinder head. When guides wear, oil control suffers and valve temperatures rise, which can lead to burnt valves, poor compression, and reduced engine life. A 2nd oversize guide allows worn or previously machined heads to be rebuilt correctly, restoring the necessary interference fit and valve stability.

This guide features a 13.21mm outer diameter, making it the 2nd oversize option, with a 9mm internal diameter to suit standard 9mm exhaust valve stems. The 64mm overall length matches original Type 4 exhaust guide dimensions, ensuring correct valve geometry and rocker alignment. Depending on supplier, some guides may be supplied without the top shoulder; this has no effect on performance or retention, as the press fit within the cylinder head securely locates the guide.

Each engine requires 4 exhaust valve guides.
Sold individually, so you can order exactly what your rebuild requires.

Technical Specifications:

• Type: Exhaust valve guide

• Oversize: 2nd oversize

• Outer Diameter (OD): 13.21mm

• Inner Diameter (ID): 9mm

• Length: 64mm

Vehicle & Engine Fitment:

• T2 Baywindow Bus – Type 4 1700cc, 1800cc, 2000cc (1972–1979)

• T25 / T3 Bus – Type 4 air-cooled and water-cooled engines (1980–1992)

• Porsche 914 – Type 4 engines (1970–1976)

• VW Type 1 – Selected 1600cc engines with 9mm stem exhaust valves

Recommended Associated Parts:

• Standard 9mm exhaust valves

• Valve guide seals (where applicable)

• Exhaust valve seats (recommended during cylinder head reconditioning)

• Valve springs, retainers, and collets for a complete head rebuild