9mm Exhaust Valve Guide - 1st Oversize - Type 4 Engines

This 1st oversize 9mm exhaust valve guide is intended for Volkswagen Type 4 cylinder heads where the original valve guide bore has worn or been machined oversize during reconditioning. It is suitable for Type 4 1700cc, 1800cc, and 2000cc engines fitted to Baywindow Buses and Type 25 (T3) Buses in both air-cooled and water-cooled form, as well as Porsche 914 engines. It can also be used on selected Type 1 1600cc engines that run 9mm stem exhaust valves.

The valve guide’s role is to accurately support and align the exhaust valve as it opens and closes, ensuring correct valve seating and efficient heat transfer from the valve into the cylinder head. Exhaust valves are subjected to extreme temperatures, and a worn guide can quickly lead to oil consumption, loss of compression, and premature valve or seat failure. Using an oversize guide restores the correct interference fit in a worn head, extending the service life of the cylinder head without the need for replacement.

This guide features a 13.11mm outer diameter, making it the 1st oversize option, with a 9mm internal diameter to suit standard 9mm exhaust valve stems. Overall length is 64mm, matching original Type 4 exhaust guide dimensions for correct valve geometry. Depending on supplier availability, some guides may be supplied without the original top shoulder. This does not affect performance or retention, as the guide is securely held in place by its press fit within the cylinder head.

Each engine requires 4 exhaust valve guides.
Sold individually, allowing you to purchase the exact quantity required.

Technical Specifications:

• Type: Exhaust valve guide

• Oversize: 1st oversize

• Outer Diameter (OD): 13.11mm

• 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 head overhaul)

• Valve springs, retainers, and collets when rebuilding heads