Hey this is for all the people using stud mounted roller rockers. What kind of preload did you use on the lifters?? Like can do it like the old sbc days where I get to zero lash and go 1 full turn then lock them down?? Or is there another way I'm just not seeing?? Doesn't seem to be too many people using this style mainly the bolt down style.

Cam specs:
283*int/284*exh advertised duration
233*int/ 235*exh @.050
.619"int .621"exh lift
114* ICL 116* LSA

As always thanks for the replies everybody. Have fun!!

 

Preload should be the same whether you're using stud mounted or bolt down rockers.

 

Very nice thanks man. Appreciate it

 

Not sure what the thread is on your studs, but that will determine the preload on the lifter. For example, 3/8-24 will provide about 0.066" preload. I ran stud mounted lifters several years ago and the stud into the head was 8mm metric, but the upper stud thread was SAE (inches).

The trick is to get the wipe pattern correct along with the correct preload. This can be adjusted with the pushrod length but ultimately its the adjusting nut that will preload the lifter.

 

The studs are 3/8 -24 upper and 8mm into the head. Would I still follow the bolt down procedure and torque them down to 22 ft lbs?? Or would it be like standard sbc getting them to zero lash then tighten the nut 1 full turn or so then tighten the jam on the stud. That's the part I'm mostly confused with. This is my first LS build if you couldn't already tell!

 

No, you need to set the studs in place first. Crane recommends cleaning the hole in the heads very good and then using red loctite. Install all the studs at one time and let them set overnight. Then each rocker goes on with the piston at TDC on the firing stroke like the SBC and brought to zero lash and tightened down to set preload. Crane recommends after reaching zero lash, tighten the rocker 1/2 turn wait five minutes and then tighten another 1/2 turn. This is to allow the lifter time to bleed and prevent driving the valve into the piston. Once you set preload, tighten the jam screw while holding the adjusting nut.

Crane originally set the lifter preload pretty deep, 0.120". Think I would shoot for 0.080" which should be around 1-1/8 turns on the 3/8-24 thread.

You might be able to find Crane's instructions with Google, either through Crane or through Vinci Performance. I wouldn't use the same number of turns to set preload though.

What rockers are you installing?

 

Awesome good info! thanks a bunch. I'm installing Lunati voodoo 1.7 roller rockers on my LSA heads. They got an offset intake like the ls3 head

 

As I stated above, check the wipe pattern. Lunati has a tech article on how to do this: Valve Train Geometry Verification

Don't they have installation instructions with the rockers?

Do these rockers use guide plates?