90.5mm + 92mm Barrel Spacer Kit (0.020" Thick) - Type 1 Engines

Cylinder base shim set for aircooled VW Type 1 engines fitted with 90.5mm or 92mm cylinders and pistons.

These precision-engineered shims install between the cylinder barrel and crankcase to alter engine deck height and fine tune compression ratio during engine assembly. Increasing the cylinder spacing slightly increases combustion chamber volume, helping reduce compression while ensuring correct piston-to-head clearance.

Cylinder base shims are commonly used during performance engine builds, particularly on 1776cc and 1835cc engines, as well as custom stroker combinations where accurate deck height setup is essential. They are also ideal for compensating for machining work such as flycut cylinder heads or case decking.

Designed for use with 90.5mm and 92mm barrels commonly fitted to larger capacity Type 1 engines.

Manufactured to 0.020″ thickness (0.508mm), making them suitable for moderate deck height corrections and compression ratio adjustments.

Sold as a set of 4, enough for one complete engine.

We recommend measuring deck height carefully and calculating final compression ratio before final assembly. Cylinder seating surfaces should always be clean and flat during installation.

Specifications:

• Fits 90.5mm and 92mm cylinders/barrels
• Thickness: 0.020″ (0.508mm)
• Fits Type 1 aircooled engines
• Quantity: Set of 4
• Fits between cylinder and crankcase

Applications:

Aircooled VW

• VW Beetle, 1960–1979, performance Type 1 engine applications
• VW Splitscreen Bus, 1960–1967, upright Type 1 engine applications
• VW Baywindow Bus, 1968–1979, Type 1 engine applications
• VW Karmann Ghia, 1960–1974
• VW Type 3, 1961–1973, upright Type 1 engine applications
• VW Type 181 Trekker, 1968–1983
• VW Buggy and Baja models using 90.5mm or 92mm Type 1 engines