Hi all,

I just set my rockers 3/4 turn past lash. I used the method of spinnin the rod and shaking up and down till it has zero play and I can feel the rod hard to turn. Some of them I had a hard time finding lash because the rod wouldn't move up and down but I couldn't feel the drag from spinnin it, so I tightened down maybe a 1/4 turn more then I should worse case!

I think I set them up ok(for the most part), but I might have some a tad to tight. Is it bad to have them maybe 1/4 turn to tight?? Thats the worse case scenario on maybe a few of them because I probably cranked them down a little much.

Thanks

 

"Hard to turn" is beyond zero lash. Zero lash is no up and down play, the top of the lifter cup is line-to-line with the pushrod that is line-to-line with the lifter. Therefore your lifters are tighter than you planned. This can keep the valves from fully closing. If you're using the stock lifters, GM states that you can use on full turn so you're probably still OK.

 

Thats good to know, in the haynes manual it says to turn 1/2 to 3/4 turn past lash, if GM says 1 full turn then I should be clear!

Thanks

 

3/4 is WAY too much, try 1/4 and see what that gives you. You might hurt something at 3/4 and the 1/4 will give you more power. With a new cam you will be tight and possibly ding a valve.

Bret

 

I'm on stock internals, stock cam, stock everything. On a 100k miles engine.... I think you are talking if I have aftermarket crap right?

 

Shoebox has a great write-up: http://shbox.com/1/4th_gen_tech2.html#adjust_valves

 

I am finishing up redoing my lash settings on my car. Used the exact same method you state. I went till it wouldn't spin freely. I went back because I have heard of people going to tight when doing this pluse I had a bad idle and sure enough mine were all just about right, except I had a couple that were 3/4turn too tight.
So I did the running motor method and set mine to 1/4 past zero lash. I am sold on the motor running method now.

 

If ya KNOW that they are at 3/4 turn ya will be OK. The only way to get a hyd lifter TOO tight is bottom it out. Ya got over .100 adjustment in the lifter. If it won't bleed down the lifter is gunked up on the inside.
Now if ya got a cam and "toss" the lifter off the nose or not enough spring and bounce the valve off the seat the lifter at 3/4 turn will take up that slack and hold the valve open to 3/4 turn. If ya had it set at 1/4 turn it wouldn't hold it open as far(by 1/2 turn) and less likely to run into a piston before it bleeds down.

 

Take the covers off and readjust them with the car running. It takes 10 minutes to do and is by far the easiest method. Most accurate. Simple. Now go get readjusting.