You have likely heard of variable valve timing by one of the names manufacturers have for the system, such as VVT-i or VTEC.

VTEC is a type of variable valve-timing system developed and used by Honda. It stands for Variable Valve Timing & Lift Electronic Control. ... using real Honda engines and visual diagrams.

Aprilia VVT diagram showing valve tech 1 of 4 Suzuki, BMW, Kawasaki, Ducati and Yamaha have all taken steps into variable valve timing and now Piaggio are developing their own setup for a future ...