Roller Rockers
Some of us were lucky enough to snag the Crane Cams compressor before they went out of business. Pretty sure there are a few copycats available somewhere.
for the cam yes you got .02x in play that you are not running for lift..its pretty easy to understand...your cam has x amount of lift..but then you have your lifters,push rods and rockers before you get to the springs which open the valves as everyone knows an put a gap or preload on,it changes..
Now say on a solid roller or solid flat tappet you cam called for .026 for hot valve lash..that means you use a feeler gauge in adj your rockers till you can slide said gauge under them freely and then you tighten them down..so now with a .026 gap in your system the cam is making up for that slack on the lift side so there for your cam just went from having .486 lift to .460 because you put a gap in the system.
a hyd system is the same just when you use your preload thats what puts the gap there that is called for by the cam card you set your preload which is the same thing just you use your lifters instead..theres a reason why when you adj your valve lash on these cars your supposed to use a dial indicator gauge to see how much preload you are putting in the system...
engine master mag just did a test on hdy lifters on a gen 2 engine and they played with the preloads on 3 different lifters and went from .028 all the way down to only .003 i think it was if i remember right.they highly dont recommend .003 lol
if you watch pro stock style racing or other types of drag racing if they have a spring going dead then they will try and take up some of that problem with cutting the lash down on the valve from say your .026 to like .016 to make up for the weak spring if they dont have time to swap them out
hope this helps
Tony
The Best V8 Stories One Small Block at Time
I am running trickflow guideplates and comp hardened pushrods, no problems here.
Just for the record, I'm using LT4 valve springs, Manley pushrods, and GM performance roller rockers......
i suggest you guys look into stock lt1/ls1 valve spring diameters... 1.255", the ls6 springs are 1.290", which drop right in to the lt1 valve spring pocket. you need comp PN 787-16, which are special retainers for the beehive spring. 










