OK its time to answer all my questions about how the following work: roller rockers, lifters, springs, retainers, pushrods and valves. What exactly do all of them do? Im wanting to install a cam sometime in the future, and need to know everything there is to know before i even start thinking about it! What are the benefits in getting different roller rockers and what are the different sizes for(ex. 1.5-1.6-1.7)? Im assuming that the springs and retainers go between the rockers and the valves,and the pushrods between the cam lobes and the rockers right? So where do the lifters come into play? What do the retainers do? Ok well hopefully some one will chime in and take the confusion out of this, I must sound stupid, and do admit i should already know all this by now!

 

The lifter sits on the cam lobe. The bottom of the lifter is a roller that rides on the lobe. The top of the lifter is a "cup" that the bottom of the pushrod sits in. Top of the pushrod pushes up on one end of the rocker. The rocker is a lever, with a "ratio".... the amount that it multiplies the cam lobe lift by, to arrive at the valve lift.

A cam might have a lobe lift of 0.30". With a 1.5X rocker, the valve will lift 0.30" x 1.5 = 0.45". With a 1.6X rocker, the valve lift with the same lobe will be 0.48".

The tip of the rocker pushes down on the valve stem to open the valve. The movement of the valve is resisted by the spring. The spring bears on the top of the head, and it held to the top of the valve stem by a top cup and a "lock".