Rocker arm adjustment

[rcvivian]

I rebuilt my BB 396, all new parts minus the valve springs, valves, and push rods. When I started the engine a couple of the rocker arms were clacking. I was able to silence them for the most part.

Now here's the issue: When I throttle the motor pretty well, as the RPM' s drop I get the clacking for a short period of time and it stops clacking at idle.

Any recommendations?

 

[wishuwerehere82]

How did you set your lifter preload when you put it back together? I presume you have hydraulic lifters.

You can try backing off the nut on the rocker with the engine running until the rocker arm clatters and tightening up until the clatter stops then give it an additional 1/2-3/4 turn to set the preload.

Another method I have used is to put a vacuum gauge on the intake manifold and back off the adjusting nut until you see the vacuum drop then turn back in until you get the highest vacuum reading. The adjstment point should still be between the 1/2-3/4 turn from the clatter point.

 

[rcvivian]

Thanks. I'll give the vacuum guage method a try this weekend. Hopefully it's not a weak spring on on of the valves.