At the front of the engine block of an MX5 NB (1998–2000), the timing belt ensures that the crankshaft and camshafts continue to rotate in exact synchronization. The tensioners constantly maintain the correct belt tension, ensuring that the valves and pistons move at the right time. During replacement, components of the cylinder head are often inspected as well, since this is where valve timing is ultimately converted into valve movement; wear or irregularities there directly affect the operation of the timing system.
