sbc / bbc valve train adjustment
 

The adjustment is 1/2 turn down from zero lash. (GM MANUAL SAY'S 1 TURN)

In order for the hydraulic lifter to work correctly, it must be centered.
If your valves have come out of adjustment after several thousand miles of
operation, suspect your rocker arm nuts, and replace them. They do wear out
after constant adjustments.


When adjusting your valves, tighten all adjusting nuts until all lash is
removed by feeling the rotation and up and down movement of the pushrod. Next, set your engine on
TDC #1, pointer at "0". You can now adjust the following valves:


INTAKE on cylinders 1,2,5,7
EXHAUST on cylinders 1,3,4,8


Loosen the adjusting nut until lash is felt by rotating the pushrod. Then
tighten the adjusting nut while rotating the pushrod until all lash is
removed. Now tighten the adjusting nut 1/2 full turn. This "centers" your
lifter.


After you have adjusted the above valves, rotate you engine 360 degrees
bringing the pointer around to the 0 TDC mark. This is TDC #6. Adjust the
following valves in the same manner:


INTAKE on cylinders 3,4,6,8
EXHAUST on cylinders 2,5,6,7


Your valves are now adjusted properly.
good luck and may the force be with you
as per the g.m manual..

Re: sbc / bbc valve train adjustment
 

I have used this for years and is the best way. Thanks for posting this, I always have to go to the book.

Re: sbc / bbc valve train adjustment
 

As noted previously, this is not true for all cams.

Re: sbc / bbc valve train adjustment
 

High RPM engines usually run between 1/8-1/2 turn. I generally run 1/2 turn on everything...

Re: sbc / bbc valve train adjustment
 

WHen you say zero lash which is the same as remove all lash. THat is when you can feel the push rod rotate underneath the rocker and tighten the nut until the push rod just stops the rotation correct?

Re: sbc / bbc valve train adjustment
 

Zero lash is when there is no vertical movement of the pushrod, typically when you just start to feel drag when rotating the pushrod. Tightening until you can't turn the pushrod is far too tight!

Re: sbc / bbc valve train adjustment
 

Ok assuming I have the right TDC on the compression stroke. I tightend each rocker nut until I felt drag on the pushrod then tightend another half a turn. I am thinking this is what mark is talking about. However Billa once I tightend the extra half turn I could not turn the pushrod anymore. Should I loosen it up again so the pushrod turns? Then when I rotated the engine 360 to finish the rest of the valves the pushrods on #1 cylinder can turn again. Now I am confused?

Re: sbc / bbc valve train adjustment
 

You're doing everything right :) You shouldn't be able to turn the pushrod once you've established the preload with the 1/2 turn.

What you're doing here is pushing against the spring inside the hydraulic lifter.

Re: sbc / bbc valve train adjustment
 

Thanks that cleared up the confusion. Now I have to make sure I had the right TDC. I think I did because both the intake and exhaust valves were closed. If I had been 180 out the exhaust would have been open correct? and should I go past 1/2 turn to 1 full turn?

Re: sbc / bbc valve train adjustment
 

Correct; if both valves were closed (on the base circle) then you are on TDC compression...right where you need to be.

Re: sbc / bbc valve train adjustment
 

Thanks Billa you have been a big help. I have the valves adjusted and right. Now all I need to do is start the engine and see if that fixed my lifter noise.

Re: sbc / bbc valve train adjustment
 

We'll be rooting for you - let us know how it goes!

Re: sbc / bbc valve train adjustment
 

im guessing since the firing order is the same for a small block and big block u adjust the same valves on number 1 and 6