Looking at camshaft design. Harold Brookshire thought you open the valve aggressively and give it a soft landing. He is right in delaying IVO and this design helped him realize this. Very smart guy, but again, he was using intuition. Comp, through their Spintron experience has found this to be opposite of what you want to do. They turned some of those lobes backwards and they worked better. Comp's new "low shock" designs impart less energy in the front end and close the valve more aggressively (relative to the opening side). Their finding (and others can disagree, but they may not be able to share their evidence due to confidentiality agreements) is that if you don't excite the spring from the get go, you can control the valve train better through the rest of the lift curve.
Among the numerous cam lobe shapes I am currently examining (including several of those submitted by you), I have found both shapes represented. Which shape is appropriate is dependent upon the spring force (never spring pressure), valve train forces (and masses), spring mass, and of course, design rpm.
Whether to design a "soft landing" valve closure is greatly dependent on whether valve "jump" is present or not.
Designing a cam lobe, or selecting a complete cam design, makes little sense unless the characteristics of the valve follower and valve train are carefully considered.
Perhaps Mike will elaborate on this.
