Waterboxer Barrel And Piston Kit - DJ - 2100cc (High Compression)

This is a standard replacement, high-compression barrel and piston set for DJ-code 2.1 Waterboxer engines, as fitted to VW Type 25 / T3 and Vanagon models from 1985 to 1992. Manufactured to OE-quality standards, this kit restores the factory 10.5:1 compression ratio, making it the correct choice for maintaining original DJ performance characteristics.

What this kit does (and why it matters)

The DJ engine is a high-compression version of the 2.1 Waterboxer, delivering stronger performance than lower-compression WBX variants. Over time, worn pistons, tired rings, or glazed barrels lead to compression loss, oil consumption, and reduced power.

This kit:

• Restores the correct DJ-specific 10.5:1 compression ratio

• Returns lost power and throttle response

• Improves oil control and combustion efficiency

• Maintains factory-correct engine behaviour and reliability

It is the correct solution when rebuilding or refreshing a genuine DJ engine and should not be substituted with lower-compression piston sets.

How it works

Each 94mm piston runs within a matched cylinder barrel, converting combustion pressure into crankshaft rotation via the connecting rods. The 36.4mm pin height and piston crown design are specific to DJ engines, ensuring correct deck height and compression when assembled with standard DJ cylinder heads and crankshaft.

The supplied piston rings seal combustion gases, control oil on the cylinder walls, and transfer heat into the barrels—critical for stable temperatures and long service life in high-compression engines.

Kit contents

Supplied as a complete set for one engine:

• 4 x 94mm high-compression pistons

• 4 x cylinder barrels

• Piston rings included

• 4 x gudgeon (wrist) pins

• Circlips / piston clips included

Technical specifications

• Engine type: 2.1 Waterboxer (DJ code only)

• Bore: 94mm

• Stroke: 76mm

• Compression ratio: 10.5 : 1

• Pin height: 36.4mm

• Quantity: Set of 4 pistons and barrels

• Quality: OE-quality replacement

Engine compatibility

Fits DJ-code 2100cc high-compression Waterboxer engines only.

Applications:

• VW Type 25 / T3: 1985–1992

• VW Vanagon: 1985–1992

Not suitable for lower-compression 2.1 WBX engines (e.g. MV) or 1.9 engines.

Helpful fitting notes

• Covers all four cylinders, regardless of side.

• Always confirm DJ engine code before ordering.

• Check piston orientation markings before installation.

• Measure ring end gaps and deck height during assembly.

• Cylinder heads should be flat and in good condition to maintain correct compression.

• Follow factory torque sequences and tightening stages when refitting heads.

Parts you may also need (recommended)

For a reliable rebuild, consider replacing:

• DJ-specific cylinder head gasket / sealing kits

• Barrel liner seals (top and bottom)

• Main and big-end bearings (depending on mileage)

• Full engine gasket set

• Fresh oil and coolant, followed by proper WBX cooling system bleeding