custom solid lifters?

[NintendoKD]

I may soon have access to a cnc machine, and am very interested in creating custom parts.  I would like to use mech lifters, and if possible, make my own.  So I guess the more appropriate question goes out to the vets, If I make a solid lifter to spec, why would I need to use spacers?  why can't I just make them to the exact height that they would otherwise need to be?  Or is that impossibe?  I maybe just a bit confused on their operation, could someone clear this up for me?  Oh, and ust in case someone was wondering I have not given up on using/making custom ceramic precups.

[truckinwagen]

you need to use replaceable shims to adjust the valve lash as the valves and their seats wear in.

over many miles the lash will change, and you will need to re-adjust you lifters.

[NintendoKD]

That is what I was afraid of   If I use a harder metal like a chromoly alloy, then the cam would wear out too, boy, what a predicament   In case anyone out there is wondering just what is going through my head right now, don't try, there is an ever informative trip to the wacky ward to help give you ideas, however, they usually don't come close.

thanks trukin,

Kevin

[macka]

why not make the chromoly lifters, and use the shims as a buffer, between the lifter and cam, that way the cam won't get worn. Chromo lifters would be pretty trick, and they have good heat properties. It would be nice to have bigger valves for better breathing. The only question is, where is the point of diminishing returns for valve size? If you do have access to a CNC shop, I have a wish list, plus I have a turbo adapter plate I'd like made in chromoly, or a good nickaloy.

[55eta]

I have always been lead to believe the shims are not used just to adjust the clearance ,and are designed to rotate in the lifter as the cam compresses the spring to reduce wear of the cam lobe and reduce the effort/power required to turn the cam shaft

[rabbitman]

I have always been lead to believe the shims are not used just to adjust the clearance ,and are designed to rotate in the lifter as the cam compresses the spring to reduce wear of the cam lobe and reduce the effort/power required to turn the cam shaft

That and probably to turn the valve too.