Reinforced exhaust valves BMW B58B30 S58B30

BMW engines covered

Launched in 2015, the B58B30 is BMW's modular inline six: 2,998 cc (82 mm bore, 94.6 mm stroke), one turbocharger and direct injection. It is found in the M140i, M240i, 340i, M340i, 440i, 540i and the Z4 M40i. The S58B30, the twin turbo M version of 2,993 cc (84 x 90 mm) introduced in 2019, powers the M2 G87, M3 G80 and G81, M4 G82 and G83, X3 M and X4 M.

The B58 uses 12 exhaust valves 11 34 8 621 264: 28.5 mm head, 6 mm stem, 99.8 mm length, held by collets 11 34 1 461 405, with valve stem seal kit 11 34 0 035 853. On these turbocharged engines, every increase in boost pressure translates directly into a hotter exhaust valve head.

SUPERTECH and FERREA reinforced exhaust valves

The exhaust valve works in the stream of burnt gases heading for the turbine: on a turbocharged engine such as the B58 or S58, the metal of its head exceeds 1,000 °C, against 760 to 870 °C on a naturally aspirated engine. It has only two ways to cool down, the seat (about 75 % of the heat) and the guide (about 20 %). An EV8 family steel, used as reference, holds only 300 MPa at 800 °C against 550 MPa at 600 °C: the head distorts, fatigues and ends up losing its seal.

All SUPERTECH valves on this page are Inconel, a nickel based superalloy that keeps 1,100 MPa at 649 °C and 554 MPa at 816 °C, about 85 % more than EV8 steel around 800 °C. The MCEVI-1400S-HS and TEVI-1058-HS-1 also have a hollow sodium filled stem: liquid from 97.8 °C, the sodium carries heat from the head to the stem. The FERREA F2430P, F2451P and F2472P are Super Alloy Competition Plus valves, for which FERREA claims 20 % more hot strength and 25 % longer seat life.

Two versions enlarge the head: the FERREA F2451P goes to 29.0 mm (+0.5 mm) and the SUPERTECH TEVI-1058-HS-1 to 29.5 mm (+1 mm). The larger flow area lets burnt gases leave faster towards the turbo and improves scavenging, with a power gain; the exhaust seats are then cut to the new size.

Exhaust valve technical specifications

The stem of the F2451P and F2472P is reduced by 1 mm towards the tip to keep the original BMW rocker arm; the F2472P, for the S58 only, requires FERREA K10123 collets.

Valve fitting

The single groove SUPERTECH valves are fitted with the KPR-6S-7 collets. The TEVI-1058T, F2430P and F2451P have 3 grooves and keep 3 groove collets. The single groove F2472P requires FERREA K10123 collets.

With a 28.5 mm head, the exhaust seats keep their size and are checked during the cylinder head rebuild. The 29.0 and 29.5 mm versions require the seats to be cut to their size.

The F2430P and F2451P fit the S58 and the Toyota Supra B58, the F2472P the S58 only; the MCEVI-1400S-HS fits the B48 and B58, and the TEVI-1058 range the B58B30.

Technical guide

Our brands

	SUPERTECH has been designing and manufacturing valvetrain parts for racing engines in the United States for more than thirty years. For BMW modular six-cylinder engines, it offers Inconel exhaust valves, solid or hollow sodium filled, with a single groove or 3 grooves.
	FERREA Racing Components has been producing stainless steel, titanium and superalloy valves since 1978. Its Competition Plus valves for the S58 and B58 are made of Super Alloy, with a single groove or 3 grooves.

How to choose

The choice comes down to two points: the head size, and the number of grooves holding the collets clamped by the retainer.

When reinforced valves become necessary

• Remap with higher boost pressure (Inconel version recommended)
• Larger or hybrid turbochargers
• Modified camshafts or valve springs
• Track days and racing use
• Burnt or out of tolerance original valves during a rebuild

Vehicle compatibility

OEM part number (exhaust valve): B58B30: 11 34 8 621 264; S58B30: 11 34 8 603 910

Don't forget the inlet valves

For a fully rebuilt B58 or S58 cylinder head, also plan the inlet valves and the exhaust valve stem seals: