DeTomaso Mailing List: June 2000, Message #135

Remember, Crane also sells (or sold) a rip-off copy of the so-called 
'fast-bleed' lifters that Rhodes first marketed. Isky also makes a version. 
All these type of  hydraulic lifters make noise at low rpm, as they leak down 
and thus shorten cam duration until around 2500-3000 rpm, when they 'pump up' 
and you get the full cam capability. The clicking noise sounds remarkably 
like solid lifter lash. They were popular as a way to pass Smog with slightly 
too-aggressive cams. Cheers- J Deryke