8mm Inlet Valve Guide - 1st Oversize - Type 4 Engines - 12.11mm

This 1st oversize inlet valve guide is designed for Type 4 air-cooled engines where the original valve guide bore in the cylinder head has worn or been re-machined. With an increased outer diameter of 12.11mm, this guide restores the correct interference fit in the cylinder head while maintaining compatibility with standard 8mm inlet valve stems.

Valve guides play a crucial role in controlling valve movement and maintaining accurate alignment between the valve and valve seat. On worn engines, the original guide bore can become enlarged or damaged, making standard-size guides unsuitable. This first oversize (OS1) guide allows the cylinder head to be correctly refurbished without replacement, ensuring reliable valve operation, improved sealing, and reduced oil consumption.

Manufactured to the correct 12.11mm OD x 8mm ID x 58mm length, this inlet valve guide is suitable for 1700cc, 1800cc, and 2000cc Type 4 engines as fitted to VW T2 Baywindow buses, air-cooled VW T25 / T3 buses, and Porsche 914 models within the specified engine ranges.

Quantity and fitting notes:

• Sold individually

• 4 inlet valve guides required per engine

• Inlet valves only
  As with all oversize valve guides, correct machining of the cylinder head is essential. The head must be accurately bored to suit the 12.11mm guide before installation. After fitting, the guide must be sized (reamed or honed) to achieve the correct valve stem clearance. Professional installation by an experienced engine machine shop is strongly recommended.

Suitable for Right Hand Drive (RHD) vehicles.

Technical Specifications

• Part Type: Inlet valve guide (1st oversize)

• Engine Type: VW Type 4 air-cooled

• Valve Stem Size: 8 mm

• Outer Diameter: 12.11 mm (OS1)

• Inner Diameter: 8 mm

• Length: 58 mm

• Application: Inlet valve

• Sold: Each

• Quantity Required: 4 per engine

Vehicle & Engine Compatibility

• VW T2 Baywindow: 1700cc, 1800cc, 2000cc air-cooled (1972–1979)

• VW T25 / T3 (air-cooled): 2000cc (1980–1983)

• Porsche 914:

  • 1700cc

  • 1800cc

  • 2000cc up to engine number GB0 010050