Over 30 years ago OS Giken created the first dual overhead cam (DOHC) 24-valve cylinder head for the Nissan L-series engine: The TC24-B1Z.   Z Car Garage in partnership with OS Giken debuted the first North American (LHD) Datsun 240z to run the TC24-B1Z at the SEMA show in Las Vegas, CA last week: … Continue reading OS Giken TC24-B1Z in Action!