Reinforced exhaust valves Audi S2 RS2 2.2 20V turbo 3B ADU

Audi engines covered

The 2.2 20V turbo five-cylinder powers the Audi S2 (code 3B, 220 hp, 1990 to 1992) and RS2 (code ADU, 315 hp, 1994 to 1995), the latter developed with Porsche. Its four-valve-per-cylinder head comes from the competition 20V quattro.

It carries 10 exhaust valves, run by hydraulic tappets. The Audi part 027 109 611 B measures 28.0 mm at the head, 7.0 mm at the stem and 98.2 mm in length. Higher boost, richer fuelling or sustained driving: on these often tuned engines, the exhaust side is the first to take the rise in temperature.

SUPERTECH and FERREA reinforced exhaust valves

On a forced induction engine the metal of the exhaust valve head goes past 1,000 °C, against 760 to 870 °C on a naturally aspirated engine, because the gases around it rush towards the turbine. Heat leaves by contact, about 75 % through the seat and 20 % through the guide. As Audi does not publish its steel grade, the EV8 family is used: 550 MPa at 600 °C and 300 MPa at 800 °C. Overheated, the head fatigues, distorts and ends up leaking at the seat.

SUPERTECH offers three materials: stainless steel (VWEVN-1034 black nitrided, VWEVN-1035 in EV16), Inconel (VWEVI-1034F, VWEVI-1035, VWEVI-1037), a nickel superalloy holding 860 MPa at 732 °C and 554 MPa at 816 °C, about 85 % better than EV8 steel around 800 °C, and Nimonic with a hollow sodium filled stem (VWEVI-1035-HS), a metal liquid from 97.8 °C that carries heat from the head to the stem. FERREA does not publish the material of its F6027 and F6028.

The larger heads (28.5 mm for the VWEVN-1035, VWEVI-1035 and VWEVI-1035-HS, 28.6 mm for the F6028, 29.5 mm for the VWEVI-1037) open a wider passage to the burnt gases: the cylinder empties better towards the turbo and fills more, to the benefit of power. The exhaust seats are then cut to the valve diameter.

Exhaust valve technical specifications

SUPERTECH note: the VWEVN-1034, VWEVN-1035, VWEVI-1035, VWEVI-1037 and VWEVI-1035-HS have a dished head; the VWEVI-1034F has a flat head.

Valve fitting

For this cylinder head family SUPERTECH lists the KPR-VW7-S collets, the VS-VW7-E seals and the GDE-VW8V-7A guides; FERREA publishes no associated parts.

At 28.0 and 28.1 mm, close to the Audi size, the exhaust seats are checked; from 28.5 to 29.5 mm they are cut to the chosen diameter.

The original stem seals carry Audi part number 027 109 675.

Technical guide

Our brands

	SUPERTECH Performance, in California, has been designing racing valves and valvetrain parts for more than thirty years. For the 20V five-cylinder its range goes from stainless steel to Inconel and sodium filled Nimonic, from Audi size to a head 1.5 mm larger.
	FERREA has made its valves in Florida and Argentina since Horacio Ferrea and Daniel Urrutia set it up in 1978. For the 2.2 20V turbo it supplies a valve at standard size and a version with a 28.6 mm head.

How to choose

First choose the size, which decides the work on the cylinder head, then the material:

When reinforced valves become necessary

• Turbo pressure raised after a remap (Inconel version recommended)
• Higher flow turbo
• Camshafts or valve springs replaced
• Frequent track days
• Cylinder head rebuild with worn exhaust valves

Vehicle compatibility

OEM part number (exhaust valve): 027 109 611 B

Don't forget the inlet valves

2.2 20V turbo cylinder head off? Complete it with the inlet valves: