Comp Cams 850-16 lifter preload
05-01-2008, 07:31 PM
#21
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I was referring to how many turns past zero lash you have to turn the lock down bolt till you get 22ftlbs on a non adjustable system. When I had my stock rockers on my car it took about 1 1/4 tuns from zero lash to 22ftlbs. Then with my YT RR's it takes only about half a turn to 22ftlbs once I shimmed them for the propper valve train geometry, both with a 7.350 push rod. So I was wondering if there was any correlation between full rotations of the lock down bolt and thousand's of preload. Now I have a good number to go off of I am going to use my dial indicator and measure mine.
. With the lifter on the base circle at zero lift, I expect at zero lash the rocker arm will be about 1.6 (.080") turns from seating onto the pedistal as 22lbft isn't that much. I haven't installed the pushrods yet, so I'll know more when I do. 
05-01-2008, 09:11 PM
#22
I was referring to how many turns past zero lash you have to turn the lock down bolt till you get 22ftlbs on a non adjustable system. When I had my stock rockers on my car it took about 1 1/4 tuns from zero lash to 22ftlbs. Then with my YT RR's it takes only about half a turn to 22ftlbs once I shimmed them for the propper valve train geometry, both with a 7.350 push rod. So I was wondering if there was any correlation between full rotations of the lock down bolt and thousand's of preload. Now I have a good number to go off of I am going to use my dial indicator and measure mine.
05-02-2008, 07:02 AM
#23
Thank's. I understand the shims are not for preload. I was just stating the difference between how many turns it took to lock the rocker down between the two rockers. The full turn difference led me to question the depth of my preload. It looks like now that I had about the correct depth with the stock rockers and not enough depth with the YT's. When my TFS 235's get here I am going to set the geometry on the bench like you recommended in another post and use a dial indicator to set preload. I was just going off the YT instructions of between 1/2 to 1 1/2 turn set the correct preload.
