VVTL-i is a version that can alter valve lift and timing of the valve. In the case of the valve 16 2ZZ-GE ENGINE 2 camshafts, intake valve operation and function of the exhaust valves. Each camshaft has two patches per cylinder, a lobe at low speed and high speed, high lift, long duration of the lobe. Each cylinder has two intake valves and two exhaust valves. Each set of two valves controlled by a rocker arm driven by the camshaft. Some of the toyota corolla uses this kind of engine. For more info about toyota corolla visit the Toyota Corolla repair