Just bench racing here, and I'm no engineer, so I'm probably missing something obvious.
Why hasn't anyone attempted to use a 1/4 speed camshaft?
I was looking at the design of vintage radial airplane engines, and they use a 'cam' that has a much slower rotational speed but has multiple lobes. The design is pretty much mandatory for radial engines, but why hasn't something like this been attempted on automotive or drag race engines? The benefits (as far as I can see) would be pretty significant. A slower speed would mean that you wouldn't be trying to "launch" the lifter off of the lobe, so I think that a much lower spring pressure could be used. That would be a huge benefit for multiple reasons: mainly, less rotational drag and much better valvetrain control, which is the main failure point on most race engines.
It would require a cam with 2 'risers' per lobe, and a special gear set that would reduce cam speed to half of what is currently used. I realize that would have a packaging issue to stay under a stock type timing cover, and maybe it's not possible to fit it, but it would be a non issue if a remote water pump were used and a spacer were used behind the cover (or a deeper cover was used). Of course this isn't really possible on your normal street car without some fairly significant reworking of the front radiator support area, but not on a drag only application. With electronic ignition systems, distributors aren't even needed anymore, but one could still be driven off of the gear set if desired (think front mount distributors, readily available through MSD and others).
One of the issues I can think of is the diameter of the gears needed to reduce the cam to 1/4 speed. But with a vastly decreased load on the valvetrain from less spring pressure, thinner gears could be utilized, so the gears could be double stacked to get the proper reduction. I'm also not sure how a 1/4 speed cam lobe 'riser' would look. Maybe the ramp would be too aggressive to get the valve open fast enough, since it has a shorter time in rotation to match the movement of the piston? And yes, a dry sump oil system would be required, but I'm talking about full race engines here.
What else am I missing? Surely this has been thought of at some point through the years? Heck, it was used on radial engines dating back over a hundred years ago.
