The cam can be seen as a device that translates movement from circular to reciprocating (or sometimes oscillating).
A common example is the camshaft of an automotive, which takes the rotary motion of the engine (crankshaft) and translates it into the reciprocating motion necessary to operate the intake and exhaust valves of the cylinders. That can be achieve via the use of SOHC (single overhead camshaft) or DOHC (dual/double overhead camshafts)
- Lift - Measured from the base circle to the max height of the lobe. It gives the maximum lift of the camshaft profile
- Duration - Measured as the number of crankshaft degree that the valve stays open
- Valve overlap - Measured as the number of crankshaft degree the exhaust valve is on the closing ramp but still open with the intake valve is starting to open on the opening ramp. Increasing the valve overlap will allow the exhausting gases to create a vacuum to help in pulling in the intake charge.
Too much valve overlap will cause the low end horsepower to suffer but gains in mid to high end. - Lobe separation - Measured as the number of degree difference between the intake lobe center and the exhaust lobe center. For the stock Hayabusa: the lobe separation is 0 as the intake and exhaust lobe center are both at 105/105
