Volkswagen Workshop Service and Repair Manuals

Piston: Specifications

Piston Dimensions and Clearance:

With Standard Piston Diameter 79.47 mm

Cylinder Bore Diameter ...............................................................................................................................................................................  79.51 mm

With 1st Oversize Piston Diameter 79.72 mm

Cylinder Bore Diameter ...............................................................................................................................................................................  79.76 mm

With 2nd Oversize Piston Diameter 79.97 mm

Cylinder Bore Diameter ...............................................................................................................................................................................  80.01 mm

Piston Ring Groove Clearance: 

New:

1st Compression Ring ...................................................................................................................................  0.06-0.09 mm (0.0024-0.0036 inch)
2nd Compression Ring ..................................................................................................................................  0.05-0.08 mm (0.0020-0.0032 inch)
Oil Scraper Ring ............................................................................................................................................  0.03-0.06 mm (0.0012-0.0024 inch)

Wear Limit:

1st Compression Ring ........................................................................................................................................................  0.25 mm (0.0098 inch)
2nd Compression Ring .......................................................................................................................................................  0.25 mm (0.0098 inch)
Oil Scraper Ring .......................................................................................................................................................................  0.15 (0.0059 inch)

Piston Ring End Gap:

New:

1st Compression Ring ...................................................................................................................................  0.20-0.40 mm (0.0078-0.0157 inch)
2nd Compression Ring ..................................................................................................................................  0.20-0.40 mm (0.0078-0.0157 inch)
Oil Scraper Ring ..........................................................................................................................................  0.25-0.50 mm (0.0098-0.01974 inch)

Wear Limit:

1st Compression Ring ............................................................................................................................................................  1.0 mm (0.039 inch)
2nd Compression Ring ...........................................................................................................................................................  1.0 mm (0.039 inch)
Oil Scraper Ring ....................................................................................................................................................................  1.0 mm (0.039 inch)