I came across Crane's rocker arm presentation they used at the PRI show. You may find the information interesting in terms of showing how changes in rocker arm design impact at-the-valve motion, even if you ignore the Crane sales pitch for their new product.

BTW, this is a 60+ page slide show (that could have been done w/ quite a few less repeated slides IMO)... not exactly "dial-up friendly".

great thread brad, it sounds like their idea is a great one, but of course, thats the idea behind the slideshow in the first place.

I read through it. That is basically what RobMc posted about before. There was one or two statements made that might not be 100% accurate, more marketing than science. At least they admit when using the varying rocker ratio, the faster you open it, the faster it slams on the seat and valve control becomes more difficult.

Their point that a roller tappet has some seat acceleration issue compared to a flat tappet, makes it seem like a good candidate for this technique. The roller already can accelerate in the middle and later parts of the lobe very well.

All valid points.

Some time in the past I posted some examples of how different rockers displayed varying at-the-valve lift characteristics that fit right into this topic. Not sure if they're even still accessible from the Search function or not. [EDIT - Nope, must have been longer ago than I realized...]

My on the subject is that faster isn't always better.