Adjusting Valves on a 350

Q: Adjusting Valves on a 350

My son and I are having trouble adjusting the valves on our 350 small block. We just ported the heads (edelbrock) and tried to adjust them with a steatho scope… they have hydrolic lifters and new push rods… can’t get any power out of the engine and when we crank down on the valve the noise still is there…. any ideas on how to adjust them?

A: I can’t imagine of what use a stethoscope is while adjusting valves, but I’ll tell you how I do it. I usually performed this with the engine running, and the valve covers off – do this one at a time since it can get a little messy. You may want to lay a piece of cardboard or small piece of scrap sheet metal across the head to contain some of the oil. Set it inside the lower lip that the gasket sits on, and do one side at a time if you want to. Back off each rocker nut until that valve ticks, tighten until the ticking stops, then tighten some more. How much more? That depends on if the lifters are new or not. If new, turn one complete turn, if old, go a half turn, if not too old, go 3/4 turn. Reinstall valve covers and clean up oil splashes with CRC Brakleen.

Some people prefer the static (engine not running) method, it also works well, but takes more time.

A: Here is a simpler method. It still works for non poly-locks. This is from Rock and Roll engineering web site.

Poly lock nut adjustment for hydraulic cams

1. Install poly-lock with hex end up. Thread in set screws a few turns with hollow hex end up.

2. Make sure lifter in on the heel of the cam.

3. In order to get a “feel” for the pressure of pushrod against lifter cup, push the pushrod into the lifter by hand so you can feel it’s spring tension. Tighten poly lock slowly while moving the pushrod up and down, being careful to stop turning the poly-lock just as the pushrod touches the lifter cup, and the up and down free play is taken up.

4. Now turn the poly lock one more “flat”, or a sixth of a turn. Hold the poly lock in that location with a box end wrench. Turn the inside allen set screws down until it contacts the rocker stud. Snug it with the palm of your hand. Do not tighten!

5. With the box end wrench in one hand and the allen wrench, turn both together until they tighten, or approximately 25 to 30 ft. Lbs. They must be tight, but you don’t want to be an ape either. Use common sense.

Warning! You cannot properly tighten poly locks by just turning the allen set screw.

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