Originally Posted by HJBarker 
If you over-rev (missed gear, etc.) you can find yourself in a valve-float situation, which means (worst case) your rocker arm stands a VERY good chance of coming off the HVLA (lifter) but still being lodged between cam lobe and valves... basically, your lifter will be stuck vertically between your retainers and your cam, and it can COMPLETELY DESTROY your cam, cam cap bolts, and in extreme cases, the cam journals themselves. I have done this personally - first hand experience.
Without the stoppers, it may come off, but, it will not stay in the way. The valves simply won't open, and, you'll come to a stop. This is actually a "side-of-the-road fixable" situation.
This is not to say it is certain you will throw rocker arms, but, if it happens and you have stoppers installed, it will most certainly cause permanent damage.
I have 3 recent situations on a DE where this has happened without RAS - and every time it has destroyed the valve train. Inlet cyl 4 - jammed and destroyed the cam, inlet cylinder 3 - jammed and destroyed cam, exhaust cylinder 2 jammed and destroyed rocker and chewed cam lobe.
Ive argued this time and time again here, if your getting valve float - or putting your self in a position to be getting valve float, then why would you use such big cams with the ramp rates that aggrivate float?? Its not intellignet!!
IMO RAS do their job, they maintain contact on the lifter, if the lifter suffers pump up youve got issues somewhere else, ie too high rpm or not enough oil pressure to sustain the rpm you want to work with.
If the springs arent stiff enough, and you run agressive ramp rates/duration/lift then your going to get failure eventually anyway - so what do you expect? Its ignorant to blame RAS to be the problem!
You bring up the issue of accidental over rev....On a track sure it can be easy to do at times, but hey, youve just gotta look after it. My DE has survived a mechanical over rev to 9k, but if you over rev to that or past then theres a lot more possible things that can let go
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If you've got something half intelligent to say why they dont work, then PM me.
Run them with good springs, make sure your lifter/oil pump is in check and that your not running stupid RPM limits, and you will be perfectly fine.
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