Lost Motion Spring

Description

Installs under the high-lift mid-rocker arm inside the cylinder head of DOHC i-VTEC engines. Its primary function is to maintain constant preload tension against the VTEC rocker arm while VTEC is disengaged, preventing high-rpm valvetrain chatter, lobe damage, or float. It is routinely replaced in sets of eight during valvetrain overhauls, camshaft upgrades, head rebuilds, or performance K-series swaps.