PRELOAD FOR HYDRAULIC VALVES

[mbandit]

I HAVE A HYDRAULIC CAM (MOPAR 280/280) AND A CRANE ROLLER ROCKER SET-UP.
HOW MANY TURNS PRE-LOAD DO I USE ON THE ADJUSTERS WHEN SETTING THE VALVES?

[DFS68_Charger]

1/4 to 1/2 turn of the adjuster from zero lash should be a good starting point.

DFS

[Chryco Psycho]

I agree

[mbandit]

We set them once with 1/2 preload using a new cam, went and thrashed it a bit, now they are noisy again.  What did we do wrong?  I'm running 10/30 oil, do I need something heavier?


Hey Chryco - see if you can answer my idle drop question too.

Tx,

Mel

[max]

this is how i set the hydraulic valves on my 426 hemi and it worked.

i took this from another web site because it was worded so well and i couldn't have written it to where it would have been understandable.


Remove the valvecover
1. Loosen all the adjusters one turn.
2. Place the valve cover back on the head.
3.Start the motor and let it run for a couple of minutes to pump the lifters up completely. Shut the motor off
4. Remove the valve cover and disconnect the coil wire
5. On each cylinder
Adjust the intake as the exhaust valve starts to open
Adjust the exhaust as the intake is almost closed.
While tightening the adjuster roll the pushrod between your fingertips. When you start to feel resistance that is zero lash.
Continue to tighten the adjuster 1/2 to 1 turn (this amount is debateable depending on who you listen to) I ususally use 3/4 of a turn which would equal approximately.030 lifter preload. Most manufacturers reccommend .020 to .040 preload. Most adjusters are 3/8 - 24 thread. 24 threads per inch = .042 per revolution.