How to properly adjust stud mounted rockers...
#3
TECH Senior Member
iTrader: (4)
Well, it depends. I have adjusted them two ways. When first installed with my stock heads/lifters, I followed Vinci's method. But when I installed the Morel lifters and new trays, I found the lifters were hanging up in the trays and compressing the plunger so I wasn't getting an accurate zero lash using Vinci's installation instructions. So I went to the old method of adjusting the intake with the exhaust open and the exhaust when the intake was open. At each valve I would first push down on the pushrod and make sure the lifter was contacting the cam and then take out the lash. Since the Morel's require a smaller preload, I went 1/2 turn then tightened the jam nut to 10 lb-ft and then 1/8 turn of the adjusting nut/jam nut together. With the valve closed, each turn is 0.065" of preload from the 3/8-24 thread and the 1.7 rocker parallel triangle.
As another aside, I also found that with the jam nut out on the work bench, if I installed a checking spring I could use a dial indicator to get the lift correct and move the rocker by hand to get my wipe pattern. Once I had a good pattern I measured the depth of the stud below the top of the adjusting nut. I kept playing with this until I found a range of depths that gave me an acceptable wipe pattern and then when I did my pushrod measurement I new what pushrod would put me into my range of acceptable wipe patterns when I came to the final adjusted position beyond zero lash.
As another aside, I also found that with the jam nut out on the work bench, if I installed a checking spring I could use a dial indicator to get the lift correct and move the rocker by hand to get my wipe pattern. Once I had a good pattern I measured the depth of the stud below the top of the adjusting nut. I kept playing with this until I found a range of depths that gave me an acceptable wipe pattern and then when I did my pushrod measurement I new what pushrod would put me into my range of acceptable wipe patterns when I came to the final adjusted position beyond zero lash.