A bespoke set of direct-fit valve springs specifically developed by BBR for the MX-5/Miata NC (Duratec/MZR) engine.
A must have for high rpm use and for camshafts with valve lift increases of over 1.5mm.
No machining is required for installation, the Mazda original valve seal and retainer is maintained. 30kg @ 38mm seat 80kg @ maximum valve lift of 14mm.