Type 4 Cylinder Base Gasket

This Type 4 cylinder base gasket is designed for use on all Type 4 air-cooled engines, providing a precise seal between the cylinder barrel and the crankcase. Correct base sealing is critical on air-cooled engines, as it maintains proper crankcase compression, prevents oil seepage at the cylinder base, and ensures consistent engine geometry.

Manufactured to the correct dimensions of 100 x 109mm with a 0.14mm thickness, this gasket helps set the correct cylinder height and deck clearance, which directly affects compression ratio and combustion efficiency. During engine rebuilds or top-end refreshes, replacing the cylinder base gaskets is essential to achieve reliable sealing and long-term durability.

This gasket is a new production part, made using tooling approved by Volkswagen. While it is not technically a genuine VW part and therefore does not carry VW logos, it is produced to the correct original specification and is suitable for both standard rebuilds and high-quality restorations.

Typically one gasket is required per cylinder, so a full engine rebuild will require four gaskets. When fitting, ensure the crankcase and cylinder base surfaces are clean and flat. Depending on your build, some engine builders may also choose to use a light sealing compound in addition to the gasket, but this should be done according to engine specification and build preference.

Technical Specifications

• Engine Type: VW Type 4 (air-cooled)

• Gasket Location: Cylinder base (cylinder to crankcase)

• Dimensions: 100 x 109 mm

• Thickness: 0.14 mm

• Material: Engine-grade gasket material

• Manufacture: VW-approved tooling (non-genuine, no VW logos)

Vehicle Compatibility

• VW T2 Baywindow: 1972–1979 (Type 4 engines)

• VW T25 / T3 (air-cooled): 1980–1983 (2000cc Type 4 engines)