Spring valve dataSeat pressure - 34kg (75lbs)Load - 63kg@10mm (140lbs@10mm)Maximum stroke - up to 12mmMade of chrome-silicon steel SAE9254-VFits BMW 3.0 N54, N55, S55 enginesWith this set, there is a risk of valve vibration and possible failure. the engine is minimized. Recommended for engines with stock and racing camshafts and revolutions above 7500 rpm. The set includes: 24 pcs. conical valve springs, 12 pcs. 5 mm titanium holders, 12 pcs. 6 mm titanium holders.