When this happens there is a small amount of play between the valve and rocker arm.
From the washingtontimes.com
The roller-rocker shafts allow valve angles to be splayed, resulting in optimized intake and exhaust port layout for better breathing.
From the washingtontimes.com
A rocker arm in the Daniel's engine came loose early in practice Aug. 29, resulting in a bent valve.
From the dailynews.com
The engine is also designed for easy maintenance and long life with a stainless-steel timing chain, roller rockers with twin bearings on each rocker and a less maintenance-intensive valve system.
From the nzherald.co.nz
Many automakers have abandoned once-common bucket-type valve lifters, an arrangement where the lifter is pressed directly by the cam lobe rather than a rocker arm.