90.5mm + 92mm Barrel Spacer Kit (0.040" Thick) - Type 1 Engines

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

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

Cylinder base shims are commonly used on 1776cc, 1835cc and stroker engine builds where accurate deck height measurement is essential. They are also ideal for correcting compression ratios after flycutting cylinder heads, crankcase machining or installing longer stroke crankshafts.

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

Manufactured to 0.040″ thickness (1.016mm), making them suitable for larger deck height adjustments and moderate compression ratio correction.

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

We recommend measuring deck height carefully and calculating final compression ratio before final engine assembly. Ensure cylinder seating surfaces are clean and flat before installation.

Specifications:

• Fits 90.5mm and 92mm cylinders/barrels
• Thickness: 0.040″ (1.016mm)
• 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