"has a shallow valve closing ramp to smooth out the drivetrain, and make it last longer."

pnut, I'm not sure what you are thinking here, but I'll give you my take on short ramps.

As I've explained before, a fellow can determine the length of the clearance ramps on a lobe by subtracting the 0.050" tappet lift duration figure from the advertised duration figure. Well, you can't figure the whole ramp this way, but you can get close enough for comparison purposes and that is what we're interested in here. In other words, if a cam has 0.050" lift duration of 230 degrees and an advertised duration of 280 degrees, the difference is 50 degrees, or 25 degrees on the opening side of the lobe and 25 degrees on the closing side of the lobe. Now, some lobes are ground with these clearance ramps being symmetrical and some are ground non-symmetrical. Again, for comparison purposes here, we'll assume a symmetrical lobe.

Now, if you picture the lobe coming around to make the lifter begin climbing in its bore, it is understandable that if you have less clearance ramp, the lifter will rise more quickly and there will also be quite a lot more pressure on the lobe/lifter interface than if you pushed the lifter up more gradually with a longer ramp.

Back when I was a kid, it was common to see a cam ground with 70 to 80 degrees difference (35 to 40 degrees on each ramp). But competition does strange things to a product. In order to bring something new and exciting to the market, some manufacturers began to snap the valve open and closed for more "area under curve". Comp uses the term "extreme energy" to label their products that use this design. While it is true that you can have the valve open longer for the same duration design with a "snappy action" cam, it also puts a tremendous amount of stress on the lifter/lobe interface and tends to "wipe" the lobe of lubricant more easily, leading to failure.

Another contributing factor to this cam failure epidemic that I've been seeing lately is the lack of extreme pressure lubricants in motor oils. I can't remember the others, but I know zinc is one of the minerals being left out of oils lately due to the negative impact it has on calalytic converters and the increased pressure from car makers to produce a car that will live to 100,000 miles. I very strongly recommend that any of you high performance enthusiasts out there who want additional protection use some of the specially formulated racing oils that still have these additives in them and also to always keep a bottle of GM Engine Oil Supplement in the oil. It is formulated with molybdenum disulphide, a very good extreme pressure lubricant which will help protect the cam lobes/lifter faces.