It makes no difference where the roller
is sitting atop the valve, as long as its foot print of motion stays
on top of the valve. What matters is the "angle of motion" as the
rocker moves this MOTION LINE (rocker loads) from closed valve, to
mid-lift, to full-lift. As long as the angle when closed begins with
half of the angle of motion (i.e., 12° to MID-LIFT for 24° of
full motion), then these loads will balance in a straight down
direction upon the valve, and NOT be over-arcing and shoving the
valve against the guide, causing excessive friction, heat, wear
and horsepower loss.
