I have run 1/2 turn past zero lash (non engine running) and not have any issues. Engine ran quiet and strong. This is what Comp reccomends for the Pro-mag rockers. I am also running the Comp 7/16" studs.

Many state that they adjust to 1/4 turn past zero lash.

Please post your thoughts.

 

It depends on your rpm range. 1/2 turn is as tight as I'd go but if you want to rev it higher (say 6K or more) I'd tighten it to 1/8-1/4 turn.

 

If you have stock lifters, and 3/8" studs, then 1/2 turn is optimal.

If you have stock lifters, and 7/16" studs, then 3/8 turn is optimal.

The difference is due to the thread pitch on the studs being different. Adjusting them this way will put the correct amount of preload on the lifters.

Dan

 

I'm doing 1/4 turn with 7/16" ARP studs in a 7k RPM revver.

 

Assuming this thread is about Comp Pro Mag rocker arms, IMO, the rocker has nothing to do with the desired lash setting. A rocker arm will perform the same, no matter what the lash. Lash is set by lifter type or desired lash for performance reasons.

 

I just set mine to 1/4 will let you know in a couple weeks.

 

exactly.

 

We all know what he means. Not to mention the title is not one sentence. He used ... to seperate the two.

Comp Pro-mags installed, what a pain. How many turns past zero lash?


^This could be what he is saying. You use ... to fill in the middle.

 

You are right, but he didn't let us know about lifters right?

 

Well, I am using comp 850 lifters, started at 1/4 turn past zero, and they were kinda loud. But, my tuner said loosen them to 1/8 turn and I will pick up some power, man are they loud. But, it doesn't bother me, I am more worried about them being too loose. But, he assures me its ok to do this.. I am using the bigger studs too.

 

Sorry, I have stock lifters.

 

1/16-1/12 turn, with Pro Mag's and Comp R lifters.

 

If ya have them 1/8th turn TIGHTER than"0" they shouldn't be noisy.
Do it with the engine running and "0" is when they STOP clacking and making noise, then 1/8 preload.

 

Yep, I do it running. I do one bank at a time, and I have someone start it, then I adjust each one out until it clacks, then I tighten it down with my finger until it stops. Then I do the next and next until the bank is done, then I kill the motor and set the preload. I do this to keep oil off the headers.

I may try to do each one individually. Like, back it off, then tighten it with my finger until it stops clacking, then take the wrench and do the 1/8th turn, then move on to the next... just alot of run time to throw oil everywhere...

What do you think?

 

Get ya a regular valve covers and cut the top the full length of the top of the cover minus a couple of bolt holes. Cut the sides down to almost the vertical side on the bottom. Bend the cut part back and trim some height and smooth the edges. Bolt um on and set them while they are running.

Ya need to set the preload with it running to get the lifter to back down. Otherwise they will all hold the valves open and possibly damage something or make it hard to start.