[Heftyspencer88]

I just swapped the cam in my 396 and am getting ready to set the lash on the valves. I’ve heard a few different things while reading up on the internet. Am I at zero lash when the push rod stops spinning or when I feel resistance? And how much resistance?

 

[R66]

The feel is something you develop.

To begin with, take a thin feeler gage or a small piece of paper and put it between the valve and rocker tip. As you tighten the rocker nut, move the paper or gage back and forth to determine when the zero lash is obtained (drag on the paper or gage). Then you can roll the pushrod to determine what it feels like if you choose to use that method.

Personally, I set the rockers cold before starting, but then readjust them hot. Most of the time, no adjustment is needed on a hydraulic cam.

 

[SoCal805]

IMHO, and the way I have always done it, is when you have no more "up/down" movement of the PR. Feeling resistance when spinning....you blew past zero lash a mile ago.

 

[RifRaf]

Another thing to consider is if you are adjusting hydraulic lifters. Sometimes when you are using the "spinning the push rod" method, the hydraulic lifter could bleed down as you are trying to find zero lash and the push rod will keep spinning freely between your fingers as you slowly keep tightening the rocker arm nut.

I like the "up/down" method that SoCal805 mentioned.

 

[Heftyspencer88]

So stop and do my 1/2 turn once I get no more up and down movement correct?

 

[RifRaf]

So stop and do my 1/2 turn once I get no more up and down movement correct?

Yes. That is what I have always done with hydraulic lifters when the cylinder for the rockers that are being adjusted is at TDC of the compression stroke.

 

[Just 1 More]

 

[SoCal805]

So stop and do my 1/2 turn once I get no more up and down movement correct?

yes. 1/2 is ok, I go 3/4

 

[Luwi67]

Are you lashing valves on a solid or setting lifter preload on a hydraulic?