Reinforced inlet valves BMW M5 E60 E61 M6 E63 E64 S85B50

BMW engines covered

The S85B50 is the naturally aspirated BMW M V10: 5.0 litres, 40 valves, twin overhead camshafts per bank and hydraulic tappets. It powers the M5 E60 and E61 and the M6 E63 and E64 (507 hp).

Its 20 original inlet valves have a 35.7 mm head and a 4.97 mm stem: BMW 11 34 7 833 775 on engines built up to August 2008, then 11 34 7 838 293, shared with the S65 V8. Higher revs, sharper camshafts or track use expose them to more heat and impact.

SUPERTECH reinforced inlet valves

The inlet valve opens the way for fresh air, lands back on its seat at every closing and slides continuously in its guide, at 400 to 550 °C. Across that range the chrome-silicon steel of conventional valves drops from 500 MPa at 500 °C to 250 MPa at 600 °C, 50 % less strength.

The SUPERTECH valve is machined from stainless steel and black nitrided: the hardened stem surface wears less in the guide and resists scuffing better. Its 4.97 mm stem matches that of the original valve.

Inlet valve technical specification

Fitting details

The SUPERTECH valve keeps the single groove of the original valve.

Supplied in standard size, it fits seats reconditioned during the cylinder head rebuild, with no machining to a new size.

Clearance is taken up by the hydraulic tappets: no adjustment is needed after the valves are replaced.

Technical guide

The brand offered

From its California workshop, SUPERTECH Performance has designed and built valves, springs and guides for racing for more than thirty years. Every batch is inspected by ultrasound, X-ray and laser before shipping.

When reinforced valves become necessary

• Higher-lift camshafts or stiffer springs
• Raised rev limit
• Supercharger added
• Cylinder head rebuilt for track or track days
• Marked or worn original valves

Compatible vehicles

OEM part number (inlet valve): 11 34 7 833 775 / 11 34 7 838 293

Related products

With the head off, replace the exhaust valves of the same engine as well: