collapsed lifters?

[CorvetteBoy]

is that when the lifter is stuck down?? please help me out here! thanks!

 

[psychlow]

AFAIK, collapsed lifters are lifters that don't "pump up" with oil. If you have them out, you should not be able to compress them by hand at all without letting out the oil first. Usually the lifter's seals are shot when this happens, so it can't build up pressure.

When/if this happens, the lash becomes way out of spec (these really aren't "lifters", they're hydraulic lash adjusters). The valve won't open as far as it should, and power will suffer.