4G63 Cylinder Head Failure: The Cost of Poor Installation

In this video, Dave dives into the catastrophic failure of a 4G63 cylinder head we machined for a customer. Despite our precise craftsmanship, poor installation practices caused irreparable damage to the head and valvetrain. We’ll show you the aftermath, explain what went wrong, and discuss how improper alignment during installation led to the geometry of the valvetrain being thrown off. This is a cautionary tale for anyone building engines—proper installation is just as critical as quality machine work.