Head swap

[deadbeat]

I have a motor I am putting in my 1997 ccsb vortec 5.7, I cracked one of the heads and now have to put one off my old motor on it. The ones on the old motor were put on a couple years ago and have no problems. I was told to unbolt the head without loosening the rocker arms and install it on the other motor torqued correctly and I would not need to adjust the valves. Is this correct?

 

[kennythewelder]

no not really, but there is no reason to loosen the rocker arms. They can always be adjusted after the heads are installed. I have put heads on a lot of engines in my life, and I have never loosened up the rocker arms. I just did my adjustments after the heads were installed. Also remember that Vortec heads are different from TBI and any other Gen 1 heads. Vortec heads have a different intake bolt pattern

 

[deadbeat]

no not really, but there is no reason to loosen the rocker arms. They can always be adjusted after the heads are installed. I have put heads on a lot of engines in my life, and I have never loosened up the rocker arms. I just did my adjustments after the heads were installed. Also remember that Vortec heads are different from TBI and any other Gen 1 heads. Vortec heads have a different intake bolt pattern

They are both vortec motors, I guess I need to read the book on how to adjust the valves, never done it before.

 

[kennythewelder]

Here is a video in setting the valve lash, or valve adjustment. The video is a little long, and he aluminum rocker rollers, but the adjustment is the same process. You just need to check the specs for you stock truck.https://www.youtube.com/watch?v=9mbxIkb4JTM

 

[deadbeat]

Here is a video in setting the valve lash, or valve adjustment. The video is a little long, and he aluminum rocker rollers, but the adjustment is the same process. You just need to check the specs for you stock truck.https://www.youtube.com/watch?v=9mbxIkb4JTM

So based on that video I need to adjust each cylinder individually? Turn motor over and adjust by firing order until the intake valve closes, the turn 1/4 of turn on crank. Tighten until pushrod gets a little drag, turn 1/4 more. Continue on firing order?

 

[comerz]

I just did it like this.... Make sure all are rockers are loose; turn crank until you see one lifter rise. Now, on the opposite valve (if its your intake valve opening, do your exhaust; and vise-versa) tighten while twisting pushrod until you cant twist with your fingers anymore, then 1/4 turn. Repeat until all are done. As a tip, I would take little sticky notes or something and mark which ones ive done so you get all of them. I did it like this and she cranked right up without any knocking what-so-ever.

 

[slowburb]

Make sure the lifter is on the base circle of the cam lobe. EO/IC is the most straightforward way to do this. You need the rocker and lifter at zero lash. This is the tricky part. If you spin it between your fingers until it stops you are WAYYY PAST zero lash. Zero lash is the point where all of the vertical slack is gone. Tighten the rocker nut with a ratchet in one hand, and keep sliding the pushrod up and down until it is just barely tight. The pushrod will still spin between your fingers. After you find zero lash, add your desired amount of preload. This is to sink the lifter plunger into the middle of its travel inside the lifter body. As a gereric rule, a half turn of preload is probably ideal. With determination and trial/error, you can do it yourself.