wyrmrider
Well-Known Member
There are several ways
one goal is to minimize sweep across the valve stem, upi want the narrowest pattern
being in the center does not really matter unless really near the edge as roller converts the force to straight down as opposed to iron rocker
one easy check is to put a valve in the head and raise it to half net lift (less lash if solid cam) put a clothes pin or worm gear clamp on an old stems seal and clamp it down
play with the shaft and rocker till your get the centerline tangent to the valve (at right angles) you can also place the roller (or iron contact point) in the center of the stem and measure the shafts new location.
make shims
notice how a change in lift would slightly change the location- and that intake and ex may be different
not a big deal
when you have the cam and a lifter in put it on the base circle with valve closed and measure for pushrods
If the head and head gasket are on drop a lifter (or a pair) in, put in an adjustable pushrod(s) rocker (s) on a shaft and sit gently on stands
turn the motor over till the cam is at half lift (net)
secure valve as above
adjust the pushrod till the rocker centerlines are tangent to your half lift valve- measure for shim
either of the above compensates for long or sunken valves or lash caps, or a reduced base circle
for a stock lift (sorta) cam just make the shim about half the roller (.400) for a roller rocker- no adjustment necessary for iron (unless base circle is cut down)
put a checking pushrod and check pushrod length
post up some photos
one goal is to minimize sweep across the valve stem, upi want the narrowest pattern
being in the center does not really matter unless really near the edge as roller converts the force to straight down as opposed to iron rocker
one easy check is to put a valve in the head and raise it to half net lift (less lash if solid cam) put a clothes pin or worm gear clamp on an old stems seal and clamp it down
play with the shaft and rocker till your get the centerline tangent to the valve (at right angles) you can also place the roller (or iron contact point) in the center of the stem and measure the shafts new location.
make shims
notice how a change in lift would slightly change the location- and that intake and ex may be different
not a big deal
when you have the cam and a lifter in put it on the base circle with valve closed and measure for pushrods
If the head and head gasket are on drop a lifter (or a pair) in, put in an adjustable pushrod(s) rocker (s) on a shaft and sit gently on stands
turn the motor over till the cam is at half lift (net)
secure valve as above
adjust the pushrod till the rocker centerlines are tangent to your half lift valve- measure for shim
either of the above compensates for long or sunken valves or lash caps, or a reduced base circle
for a stock lift (sorta) cam just make the shim about half the roller (.400) for a roller rocker- no adjustment necessary for iron (unless base circle is cut down)
put a checking pushrod and check pushrod length
post up some photos
