Reinforced exhaust valves Audi S4 RS4 A6 allroad 2.7T 30V

Audi engines covered

The 2.7T is Audi's turbocharged V6 with five valves per cylinder. It is found in the S4 B5 (AGB, AZB) from 1997, in the RS4 B5 (ASJ, AZR) from 2000 to 2001, and in the A6 C5 2.7T (AJK, APB) and the allroad quattro C5 2.7T (APB) until 2005.

Each cylinder has three inlet and two exhaust valves: 12 exhaust valves are therefore to be replaced, operated by hydraulic tappets. On the APB and AJK, the original part 058 109 611 E measures 29.9 mm at the head, 6 mm at the stem and 103.9 mm in length. A remap or larger turbos increase the heat they have to withstand.

SUPERTECH and FERREA reinforced exhaust valves

Opened on every cycle into a flow of burnt gases, the exhaust valve of a turbocharged engine sees the metal of its head exceed 1,000 °C, against 760 to 870 °C on a naturally aspirated engine. To cool down it relies mainly on its seat, which takes about 75 % of the heat, then on its guide, about 20 %. For the original steel, the EV8 family is used for comparison: 550 MPa at 600 °C, 300 MPa at 800 °C. Overstressed, the valve overheats, fatigues, distorts and ends up leaking on its seat.

The SUPERTECH AEVI-1103, AEVI-1103S and AEVI-1106S are made of Inconel, a nickel superalloy that keeps 1,100 MPa at 649 °C and 554 MPa at 816 °C, about 85 % better than EV8 steel around 800 °C. The AEVI-1106S-HS moves to Nimonic, with a hollow sodium filled stem: molten from 97.8 °C, the sodium carries heat from the head to the stem. The FERREA F1554P keeps the original head with 3 grooves.

The AEVI-1106S and AEVI-1106S-HS enlarge the head from 29.9 to 30.9 mm: burnt gases leave the cylinder faster, scavenging improves and the engine gains power, provided the exhaust seats are machined to this diameter.

Exhaust valve technical specifications

Valve fitting

The 3 groove AEVI-1103 and FERREA F1554P are fitted with 3 groove collets; the other three SUPERTECH valves, with a single groove, with the KPR-6S/7.

At the standard 29.9 mm size, the exhaust seats keep their diameter; at 30.9 mm, they are recut to the new size during the rebuild.

For the valve stem seals, the original part number on the APB and AJK is 036 109 675 A.

Technical guide

Our brands

	SUPERTECH Performance has been designing racing valves and valvetrain parts in California for more than thirty years. For the 2.7T, it offers Inconel with a single or 3 grooves, in standard or +1 mm size, and a sodium filled Nimonic version.
	FERREA, founded in 1978 by Horacio Ferrea and Daniel Urrutia, makes its valves in Florida and Argentina. On the 2.7T, its F1554P keeps the original head and the 3 grooves.

How to choose

Choose the groove first, which decides the collets, then the head size:

When reinforced valves become necessary

• Raised boost pressure (Inconel version recommended)
• Larger or hybrid turbos
• Changed camshafts or valve springs
• Track sessions
• Rebuilt cylinder head with marked exhaust valves

Vehicle compatibility

OEM part number (exhaust valve): 058 109 611 E (APB, AJK)

Don't forget the inlet valves

For a fully rebuilt 2.7T cylinder head, also replace the inlet valves and the valve stem seals.