Wow, I have no idea what is being said in this thread. Lifters are the little pieces that hit the cams that move the valves up and down right? What's so good about having lighter or solid lifters?
its a little more complicated than that...
simply put, the cam lobe 'hits/lifts' the lifter or cam follower, which contacts the rocker arm. the rocker arm then redirects that force roughly 180 degrees and pushes down on the valves to open them. finally the valve spring works against the valve to close it again.
hydraulic lifters are good because valve clearance is a lot more lenient. since they are 'hydraulic' they have fluid (engine oil) flowing through them. they allow for compensation due to engine temperature (engine components continuously expand and contract). hydraulic lifters pretty much always maintain contact with the other valvetrain parts.
solid lifters are a lot more durable than hydraulics (less moving parts is always a plus). however, the valve clearance must be maintained for proper engine operation, again this is because of the expansion and contraction of engine parts..
most people switch to solid lifters because they can simply take a more crucial beating than your average hydraulic lifter
again, this is just a basic run down of the lifters and the cylinder head.. hydraulic lifters actually have more to them
anybody know if german cars ever used roller lifters? those might work better than solid lifters...