Type 4 Cylinder Head Stud - Top - 175mm (Also Waterboxer Engines)

This 175mm cylinder head stud is a versatile replacement used across both Type 4 aircooled engines and Waterboxer (WBX) engines, making it an essential component for a wide range of classic Volkswagen engine rebuilds. It is fitted to Baywindow Buses, early aircooled Type 25 / T3 models, and later Waterboxer-powered Type 25 / T3 Transporters.

Sold individually, this stud allows precise ordering whether you’re replacing a single damaged stud or completing a full engine overhaul.

What this part does

Cylinder head studs clamp the cylinder heads securely to the engine case, maintaining correct sealing for combustion pressure and, in the case of WBX engines, coolant passages. Proper stud length and strength are critical to ensure even clamping force and long-term engine reliability.

Worn, corroded, or stretched studs can lead to head leaks, compression loss, and premature engine failure—especially on engines exposed to repeated heat cycles.

How it works

The stud threads into the engine case and provides a fixed anchor point for the cylinder head nuts. When tightened to the correct torque sequence, it ensures uniform clamping across the head. The 175mm length is specific to the applications listed below and must be matched correctly with other stud lengths where required.

Key specifications

• Stud length: 175mm

• Quantity: Sold individually

• Quality: Durable replacement suitable for rebuilds

• Application: Type 4 aircooled & WBX engines

Quantity required per engine

• Type 4 aircooled engines (1700–2000cc):

  • 8 studs required per engine

• Waterboxer engines (1.9 & 2.1):

  • 4 studs required per engine

Important WBX fitting note:
To complete the full set of cylinder head studs on a Waterboxer engine, you will also require:

• 4 × 191mm cylinder head studs

  • VW part number: 025101143A

Engine compatibility

Aircooled Type 4 engine codes:

• CA, CB, EA, W – 1700

• AW, AP – 1800

• CJ, CU, CV, GD, GE – 2000

Watercooled Waterboxer (WBX) engine codes:

• DF, DG, DH, GW, SP, EY – 1.9

• DJ, SR, MV, SS – 2.1

Vehicle applications

• VW T2 Baywindow Bus: 1972–1979

• VW Type 25 / T3 (aircooled & WBX): 1980–1992

• Porsche 914: 1970–1976

Fitting recommendations

• Inspect engine case threads before installation

• Replace studs as a matched set during major rebuilds

• Use new head nuts and washers where specified

• Always follow factory torque settings and tightening sequence

This 175mm cylinder head stud is a critical fastening component for ensuring dependable head sealing and long service life on both Type 4 aircooled and Waterboxer Volkswagen engines.