What is a roller valve spring?
Roller rocker arm. The rocker are in the head that transfers the
camshaft action to the valve. Opens and closes the valves. On a
roller rocker, there is a small roller on the lifter end of the
rocker arm. Some small gain in performance due to lack of friction.
Very small. In a complete engine overhall where everything is done
just right to improve performance, each little bit can have a
combined affect that does improve the overall performance. Changing
the rockers by themselves is not wort the expense.