Cylinder head

On top of the engine block of an MX5 NB (1998–2000) sits the cylinder head, where air, fuel, and exhaust gases literally intersect. This is where the valves, camshafts, and combustion chambers are located—components that determine how efficiently the engine breathes and performs. Due to the high temperatures and constant stress, this is one of the most complex parts of the powertrain. During overhaul work, the bolts and nuts responsible for properly securing the cylinder head to the engine block are often addressed, as correct preload is essential for a good seal. It is precisely at this level that even minor deviations can have major consequences for the engine’s performance, reliability, and service life.