Why trash the rotators?

The rotators are quite heavy, so when the RPMs go up, that's a lotta mass to start and stop every stroke. Lighter retainers = less reciprocating mass = higher rpm, and less tendency for valve float - same goes for pistons, rods, etc

Every gram of weight reduction in the valvetrain adds 35 to 40 rpm potential to the engine. So, a weight reduction of 10 grams could theoretically add 350 to 400 more rpm to the engine with no other changes to the valvetrain (same springs, etc.).


http://www.tomorrowstechnician.com/...-driving-forces-behind-valvetrain-technology/

cheers