Originally Posted by Skippy722
Originally Posted by OVERKILL
Originally Posted by Ws6
Originally Posted by A_Harman
I think the 6.2 suffers from excessive mass at the valve. Ford designed it with the hydraulic lash adjuster at the valve end of the rocker arm. This means that whatever accelerations it feels from the cam are multiplied by the rocker ratio. It probably has about as much mass at the valve as a pushrod engine.
I like how Mazda did it. They seem to have figured out turbo/DI, "fill for life" transmission fluid, etc. as well.
On their Skyactive engines, Mazda uses a class 3 lever (similar to BMW's 14,000rpm S1000RR design), and a low-friction roller cam follower. But the pièce de résistance is the hydraulic lash adjuster (HLA) at the fulcrum.
FYI, that's the exact same way Ford did it on the Modular.
Same as the Pentastar v6 as well. It's a great system imo.
The end-pivot valvetrain with stationary lash adjuster at the fulcrum is the most popular type in the world. It has pretty much taken over from the direct-acting bucket lifter style. It has advantages of being able to package a roller cam follower for low friction, lower engine height because the cam follower is next to the valve stem instead of on top of it, and ability to achieve higher valve velocity than the direct-acting slider follower style.