Porsche 991 GT3 MK2 4.0 Cylinder Head 4-6 9A110401296

For the Porsche 911 GT3 (991.2 generation, 2017–2019), the cylinder head under part number 9A1.104.012.96 is a highly specialized component designed for the 4.0L flat-six (MA1.76 / DGGA engine). This engine is essentially a street-legal version of the 991.2 GT3 Cup racing engine, featuring a rigid valve train without hydraulic lash adjusters.

1. Technical Specifications

This part number refers to the Right Cylinder Bank (Cylinders 4-6).

• Application: Porsche 911 GT3 (991.2), GT3 RS (991.2), and 911 R.

• Engine Codes: Primarily DGGA (991.2 GT3) and DGGB (991.2 GT3 RS).

• Design: Forged aluminum alloy, optimized for high-RPM stability (9,000 RPM redline).

• Key Feature: This head is designed for the “shimming” valve adjustment system. Unlike standard 911s, these heads utilize solid lifters where valve clearance is set manually via precision shims, exactly like the Cup car.

• Bore: $102\text{mm}$ (Standard for the 4.0L displacement).

  2. Component Contents

When ordering part 9A1.104.012.96, the “Cylinder Head Complete” typically includes:

• The bare cylinder head casting.

• Valve Cover (Integrated): Often comes as a matched set because the camshaft carriers are integrated into the housing.

• Camshaft Bearings: Pre-machined surfaces for the high-revving cams.

• Note: Usually does not include the valves, springs, or camshafts unless specified as a “Head with Valves” (which typically uses suffix 95 or BX for remanufactured units).

3. Related Service Parts

If you are replacing or servicing this head, you will require the following 991.2-specific gaskets and hardware:

• Cylinder Head Gasket (Cyl 4-6): 0PB.103.148.B (Standard) or Athena Cooper Ring for high-performance builds.

• Head Bolts (Torx M12): 9A7.008.633.00 (Outer) and 9A7.008.634.00 (Inner). These are stretch bolts and must be replaced.

• Spark Plug Tubes: These should be inspected for cracks and typically replaced during a head swap to prevent oil leaks into the plug wells.