I recently installed 1.6 rocker arms and I followed the same procedure as my Haynes manual with setting lash then proceeding with the amount of turns. After I start the motor with valve covers on I can hear some ticks. So I take the covers off, tighten the problem areas (roughly around clyn. 8 and 3) about a 1/4 turn, then proceed with about a 1/8 of a turn on the rest. I start it up and I can still hear ticks around my #8 and #3 cylinder.

My friend suggested I buy a valve cover off a wreaker or cut the top off to control oil spillage then tighten accordingly but how tight is too tight?

 

There is no torque on the Chevy rocker nuts. The nut simply allows the pushrod to push up on the rocker against the nut to give it a fulcrum point.

The exact specification for a hydraulic valve adjustment is 0.030-0.060" from zero lash. That's how much preload is placed on the plunger inside the lifter.

Zero lash is done with the lifter on the base circle of the camshaft. Wiggling a loose pushrod, you adjust the rocker until any slop in the pushrod is gone. That's zero lash. All components are touching each other just enough to say they're touching. You then tighten the rocker nut 1/4 to 1/2 turn more to achieve the proper lifter preload. Once the lifter bleeds down, the pushrod will feel loose again. Don't tighten the rocker any more. This is normal.

Using 1.6 ratio rockers moves the pushrod closer to the pedestal. This means the slot in the head that the pushrod goes through must allow the pushrod to be in the new position without touching any other metal. The sound you hear may be pushrod to head interference.

 

so this is normal? should I re-adjust the preload over again b/c I already tightened them a bit? or just leave it alone?

 

You need to go through the whole lash procedure and set each one in the firing order as it comes up to TDC. Usually if you have one or two clacking you just missed one, it's easy to do. Just mark it down as you go and just go through each cylinder again to be safe. No need for the car to be running or to make special valvecovers or anything.

 

Ok, its a 82 305. Haynes said 3/4 turn, after zero lash. the procedure was listed in the manual but if its easier to go through the TDC for each cylinder i'll do that. thanks

 

If you're going to run it at any kind of RPM, 3/4 turn may be a problem due to the potential for lifter pump-up. It's been remarked numerous times by many of us here that 1/2 is more than plenty to get the plunger into the "self-adjust" range in the lifter body with a minimal risk of float form pump-up. Then again, we're a bunch of old guys...

 

Heres the thing, I don't know if I was in a rush to get this done or whatever, but when I first went through the sequence of going to TDC then adjusting the specific intake and exhaust valves, spinning the crank 360 and do the others. I initially did 1/4 turn for each. I started the motor and it was very noisey and my number 8 rocker actually came off. I shut it off immediately. redid the process with 3/4 turn, and now I just have a couple noisy ones.

I inspected the pushrod for clyn. 8 and it wasn't bent at all.

When I set my tdc I felt for the pistion on Number 1 on its highest point. Should I have just sent the timing mark to 0? Do you think that's why im out?

 

Using the timing mark is the simplest way. With the timing mark on the balancer lined up to the pointer, you're either on #1 or #6 TDC. With the valve covers off, it's easy to determine which cylinder is at TDC even if the adjustment is off.

I've never had an issue adjusting my valves like this even with big roller race cams. The valve you're adjusting is never on an overlap.

Standard 18436572 firing order

#1 TDC
INT 1,2,5,7
EXH 1,3,4,8

#6 TDC
INT 3,4,6,8
EXH 2,5,6,7

So with the timing marks lined up, look to see if the #3 intake is opened. If it is then you're on #1 TDC. If it isn't open, look to see if #3 exhaust is open. If it is then you're on #6 TDC.

After 8 valves are adjusted, roll the engine over 360 degrees and adjust the other 8. 1/4 turn from zero lash is the minimum adjustment. 3/4 turn is the maximum. The spec is roughly 1/2 turn but the way the hydraulic lifters work, it doesn't need to be 100% accurate. Too loose and the lifters will clatter. Too tight and you can collapse a lifter or do any other kind of valvetrain damage.

It's also possible that the cam lobe is wiped out which requires you to constantly tighten the rocker to compensate for a loose rocker. A dial gauge on the end of the pushrod while you roll the engine over can tell you if the lobe lift is the same as a known good lobe.

 

I pulled the exhaust manifold off and the number 8 exhaust port was moist. So wtf. how is it that I just rebuilt the heads last fall, put maybe 5km on the car over winter till now, I install 1.6 rockers and now this problem. Thanks for the input guys. Im gonna redo the preload according to your info. And see what happens. I hope theres nothing wrong with my lifters or cam, I want to drive the car this summer

 

Ok, so I redid the sequence according to your direction and it still ticks! so I drove it home (1hr trip down hwy) and she was running HOT HOT HOT. had to pull over cuz she was overheating. So im thinking its my Timing..... Gonna check it out tomorrow