Great answers so far people...
NOT!!!! :lmao:
A solid cam, uses a solid lifter. Its pretty much just a round hollow chuck of metal. The lifter rides on the cam lobe and the cam lobe moves lifter up and down. A solid cam needs a lash setting, a space between rocker arm and valve stem
A hyd cam uses a lifter that is like above but also has a spring and plunger inside it. The lifter fills with oil and pumps up. On adjustment, no slack or space is needed between the rocker and valve stem as the lifter bleeds off and pumps up with oil to chusion the valve train.
Solid cams do not "hit harder" or run rougher then a hyd cam. The cam duration and LSA is what causes a cam to sound wild or mild. Both a solid and hyd. will and can sound rough or smooth based on the size of it.
Yes a solid cam is louder running. It has a noticeable click. Kind of sounds like a sewing machine running, again thats due to the slack in the lash adjustment
The main problem with most solid lifter cams are their power bands are usually high RPM, because they're designed to rev very high for racing applications. Most production solid cams have lots of overlap, so they're piss poor for pulling vacuum, and if you're running accessories or have an automatic trans, can be a problem.
Hydraulic roller cams are much better suited for street/strip application, allow for fairly high RPM, and you don't have to worry about adjusting valves at all. Plus, they're friendly for engines running accessories, especially stuff dependant on engine vacuum.
Hope this helps a little....