when looking at performance cams, what exactly is the "duration" and "lift".. like how does it work in reference to the motor? and what kind of improvements do you see with higher durations / lifts or lower durations/lifts?

 

duration is how long it holds the valve open and lift is how far it opens, more of both allows more fuel/air in to the engine.

 

cams are something you just have to dig into and research

lift is measured in inches. you'll see something like .576/.580 that means that, measured at the valve, the intake valve is opening .576 inches and same thing for the exhaust valve. LSA is the difference in the center of the cam's exhaust lobe and intake lobe. it is measured in degrees. you can increase the lift of a camshaft by making changes in a rocker's ratio. too much duration makes overlap and overlap reduces the quality of your idle and low end because it is reducing cylinder pressure by having the valves hang open.

there's a million different things to learn about camshafts and valvetrains in general and a good cam will make the difference in a quick car and a fast car. get on google and do your research