7/31/2019 Crane Cams-Hydraulic Lifter Adjustment
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Use the adjusting sequence as above to insure that the lifteris
on the heel of the cam when preload is measured.Generally, pushrods
for each cylinder should be the sameunless valve stem heights are
not correctly matched. Whenchecking lifter preload, make sure the
valve is not open onthe one you are checking. You may need to wait
a few min-utes for the lifter to bleed down.
It may be necessary to change pushrod length, useadjustable
pushrods, shim rocker stands or shafts, installstraight screw-in
studs in place of stock bottleneck type, useallen set adjusting
nuts, or machine heads for adjustablerocker arms, studs and guide
plates. Figures 1 & 2 showone method of decreasing lifter
preload on some engines byusing shims. We offer these shim kits.
See your local deal-er.
If the adjustment procedures are followed correctly forhydraulic
lifter cams, no further adjustment is necessary forthe life of the
cam.
The same adjustment procedure should be used formechanical
lifter cams. Instead of lifter preload, you mustuse the clearance
specs on the cam card for your cam.Mechanical lifter cams require a
second adjustment afterbreak-in, then periodically at tune-up time
for the life of thecam.
If these instructions are not followed, or you are not able
toget the proper distance between the rocker arm and lifter, donot
start the engine because invariably something wilbreak.
151G3/00
Place
shims
here
Figure 1. Typical installation for V-8 engines such as Olds
V-8,
some AMC V-8 and 6 cylinder and 81 and up 151 cu. in. Pontiac
4cylinder engines.
Place
shims
here
Figure 2. Typical installation for most late model Ford V-8, 6
cylin
der and 4 cylinder engines.
The shims will decrease lifter preload approximately .030, .060
or .090 depending on the shims used. Maintain a rec-ommended lifter
preload of between .020 minimum and .060 maximum for proper lifter
operation.
