It is the task of the valve drive to transmit the information, which is defined by the cam profile, to the valves as precisely as possible. For this purpose should the valve spring be as tough as needed, but also as soft as possible. If the valve spring is too tough it generates a higher internal friction the so-called towing capacity increases. If the spring is too soft is might happen that the tappet lifts the cam tip and that the exact transmission of the timing is disrupted.
Perfectly adjusted to our camshafts.
The complete set consists of eight springs, four inner and four outer.