Decades ago (OK, half a century or more), there was a product advertised in many of the performance magazines called the Varicam. The idea was a set of springs attached to a centrifugal device that ...

Eventually this trickled down to GM's incorporation of this technology into the Gen IV 6.2L L92 Escalade motor for the 2007 model year. GM's design placed a cam phaser on the face of the cam, which ...