Piston Assembly for 4.2L CGNA CAUA Engine (079107065DC)

Engine Piston Ring Set (079107065DC, 079107066DC, 079107065AD) — Compatible with Audi S5, A6, A8, Q7 (4.2L)

The Audi 4.2L V8 (CGNA/CAUA) piston kit typically comprises 84.50mm diameter pistons (specifically designed for Alusil cylinder bores), 20mm or 22mm piston pins, and is supplied as a complete set for an 8-cylinder engine. Frequently manufactured from ZL109 aluminum alloy, these kits feature compression ratios ranging from 9.5:1 to 13:1, gas-nitrided piston rings, and high-strength piston pins—making them ideally suited for building high-performance engines.

Description

CGNA/CAUA Piston Kit Key Specifications:
Engine Codes: CGNA (4.2L FSI; e.g., Touareg 7P) and CAUA (4.2L FSI; e.g., S5/RS4).
Bore Size: Standard size is 84.50mm.
Piston Pin Diameter: Typically 20mm for standard kits.
Compression Ratio: Typically 12.5:1.

Material: ZL109 Alloy.
Compression Ratio: Selectable—9.5:1 (suitable for forced induction applications) or 13:1 (suitable for high-compression naturally aspirated applications).
Coating: Tuff Coat piston skirt coating.
Piston Rings: Includes a set of gas-nitrided piston rings.
Components: The kit typically includes 8 pistons, 8 piston pins, 8 sets of piston rings, and circlips.
Compatibility: Specifically designed for 4.2L 32V and 40V FSI engines.
Applicable Models: Includes Q7, Touareg, S5, and RS4.