Valve spring B18/B20/B30

Standard spring that is designed to have a lower clamping pressure This is to protect the camshaft during break-in Also works well when tuning This spring can be shimmed to get a high pressure because it bottoms about 4mm later than standard Standard spring bottoms at approx 28mm, and this at approx 24mm Approximate pressure measured without washer (spring only) 0N @43mm 150N (15.3kg) @ 41mm 260N (26.5kg) @ 39mm 400N (40.8kg) @ 37mm 540N (55kg) @ 35mm 700N (71.5kg) @ 33mm 790N (80.5kg) @ 31mm 940N (96kg) @ 29mm 1110N (113kg) @ 27mm 1300N (132.5kg) @25mm Bottoms at 24mm Ø4.2mm wire thickness Ø27.2mm outer diameter Ø18.8mm inner diameter About 43.5mm high