HI Cooperess
The tappet ramp is the ramp from the base circle (bottom of the cam) to when the valve starts to open it can be any thing from .002 to .040, the cooper "S" has a ramp of about .022 and the reason for this is that it is very easy on the valve springs, when opening and closing the valve.
If you bang the valve open to quickly it sends a shock wave through the spring causing the spring to wobble (harmonics,spring jerk etc) then when it comes back down to close the valve you have to let it down gently on to the seat or it will bounce of the seat , (valve bounce) because the Cooper S did not have a lot of spring pressure they needed to be gentle on the opening and closing hence the long ramp.
On one of my race cams the 308 which has fast opening and closing I run a .030 ramp the tappets are set at .028 tho.
But we have learned a lot over the years opening them quickly then easing back a little to let the spring get hold of it's self then lay into it.
I have just been developing some more road cams that are making race car HP by 6000 rpm to 6500 RPM, but still trying to see what spring pressures I can get away with,it really is a step forward in the development of the A series, we just keep learning more and more about these little motors with cam design and cylinder head design, we have now found a way to get huge flow with a std valve by .350 tho lift just where road cams lift their valve to.
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Graham Russell