All rocker arms coming loose

[fostrem]

All of my rocker arms are coming loose! I put a new head on my drivers side bank of my 350SBC, and had a shop adjust the valve lash. The rocker arms were coming loose, i mean all of them, so I decided to change the nuts because they were used on a previous head. Now before I even start the engine the arms come loose again. Here is what I'm doing.

I watch the rockers as i hand crank the engine, once the #1 cylinder has had both intake and exhaust open and close I put my balancer mark at TDC. Then I removed the nuts from:
Exhaust: 1,3 Intake: 1,5,7
and put new nuts on and tightened them 1 and 1/4 turn past binding of the push rod

Then did a full turn of the crank and adjusted:
Exhaust: 5,7 Intake:3

After I did this, all the rocker arms from the first adjustment were loose again.

Am I doing something wrong?
I dont want to run the engine until I am comfortable with the results

Thank!

[INSIDIOUS '86]

I do a running lash so while the engine us running and warmed up fully I run one valve lash at a time. I loosen till it smacks then tighten it till it doesn't then go 3/4 more and do this for the rest.

If the still go loose the its either the friction nuts or something more sinister
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[fostrem]

Well I did a running lash adjustment like you mentioned and it seems as though it is not backing off anymore. I have a feeling the way that i did it i was tightening past the point of the lifter bottoming out and forcing pressure to move the nuts. possible?

[INSIDIOUS '86]

Yes that is possible. Can cause a lot of issues that way. Take a level across the rocker studs and make sure they are even. If you overtightened them it's a good idea to check to make sure the studs didn't pull out as result.
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[fostrem]

What would be the consequence of not having the rocker studs even?

[LynnJr]

On ford rockers you tighten them down all the way and if a ford guy works on a chevy it will pull the pressed in type rocker studs out of the head.

I have a ford friend who did this to his neighbors car and he called me up to see what went wrong.

You can back the nuts off and tap the studs back into place with a hammer then re-adjust the valves.

[Hook0215]

Originally Posted by INSIDIOUS '86

I do a running lash so while the engine us running and warmed up fully I run one valve lash at a time. I loosen till it smacks then tighten it till it doesn't then go 3/4 more and do this for the rest.

If the still go loose the its either the friction nuts or something more sinister
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This is the best way to do stock rockers.
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[Desert1957]

Originally Posted by fostrem

What would be the consequence of not having the rocker studs even?

This is one way to see if any of your rocker studs are pulling out of the cylinder head.

Desert

[rayfinseats]

If you are using new nuts and they are loosening up you may be pulling the studs out. This only happens usually if you are running a wilder than stock cam. If the studs are not pulling out and you have new nuts and they are still loosening up, you may need nuts that have a setscrew on top. http://www.jegs.com/images/photos/20...49-4508-16.jpg

I once had a valve rub all the way through the rocker and if you get them too tight they will wipe out your cam. I usually start with tighten them down while turning the pushrod in my fingers (lightly) at their lowest point on the cam and then start it up and do like insidious said above.

[LONGHAIR]

Originally Posted by LynnJr

You can back the nuts off and tap the studs back into place with a hammer then re-adjust the valves.

You can.......and they will pull right back out again, so don't waste your time.
Once they have moved, it is a bit more serious to fix it.
The easier of the methods requires hammering them back into the original place and "pinning" them in place. This means drilling....best done off the engine.

The other method takes even more machining, cutting down the mounting areas and installing screw-in studs......also off the engine.

Or replace the heads entirely. This one is the quickest, but most expensive way. It is also the only one that can add any performance at the same time.

[LynnJr]

They haven't pulled out yet.

[fostrem]

Ok so they started to make noise earlier so I figured I'd take a second look at the valves. I am not 100% sure that I have hydraulic lifters, but on certain push rods, I can push on them and feel the lifter depress, so they must be hydraulic right? I called a mechanic friend and he said to adjust the valves again one by one with the engine off like I did the first time. After I did this, the oil pressure was above 60 which is not normal for this truck. I'll go back and do a running valve adjustment again and see if the oil pressure goes down.

[fostrem]

Did another running job. Oil pressure has settled down and the engine sounds good. I am satisfied for now. I will update once I take it for a longer drive.

[Dylan86]

Ive seen it where the valve nuts aren't backing off, the lifters and cam lobes are actually being chewed away do most likely low oil pressure or improper break in of the engine. First run through the valve setting procedure. then mark all your nuts with a tick at 12 o clock lightly with a hammer and chisel. run the truck for a few days, if the marks havent moved, but the rockers are now loose, then you have some major internal issues, or the studs are being pulled out of the head- use a flat ruler and see if they are level. if they have rotated, then just get locking rocker nuts like such - http://www.summitracing.com/parts/cr...s-16/overview/

[LynnJr]

Fostrem
Assuming everything was done right on putting the new head in place here is a easier way to accomplish what you are doing.
First the new nuts is a good idea as once they have been backed off several times they don't work very well and won't remain tight.

On the adjusting you can put 4 marks on your harmonic balancer or your lower pulley 90 degrees apart using TDC as your starting point.
Put a breaker bar on your crank bolt so you can spin the motor and remove all 8 spark plugs.
Put the crank on one of your marks and tighten any valve that has excessive play on the new head.
Turn the motor 90 degrees to your new mark and do the same thing to any rocker arm with excessive play.
Repeat this for atleast 2 full revolutions and preferably 4 full revolutions.This will set all the valves so you can now start the motor and set them while it is running.
When you get it running look for rocker arms that are obviously not adjusted and tighten them up slowly until they seem right.This is necessary so you can hear better while your setting them.
Now go to your first valve and back the nut up slowly until you hear it clicking loudly and tighten it back up until it stops.Now re-position the ratchet or wrench so it is at 12 O'"clock and pull it down to 6 O"clock or a 1/2 turn.
Repeat on all 8 valves for the new head.
Clean up the mess but don't use any sealer on the valve cover or gasket.Let the engine run until you burn off any spilled oil and let it sit overnight.
Now that it is fully cooled down start it up and listen for any valve noise.
If it clicks at first then goes away the valves need a little bit more adjustment.
Nothing should change after this so you can glue your gasket to the valve cover only at this point.
I never try and tighten the valves more than half a turn because I always re-torque the head bolts/studs after 500 miles.
Once that is done I reset them and after a good clean up I glue everything down.
If you used assembly lube on the pushrod tips and in the rocker arms under the rocker balls they will loosen up a tiny amount as the lube bleeds off.Also if the pushrod tips are not fully seated you may get a little slop but not a lot.
The nuts should have some feel to them as you are adjusting them.If they spin on easily they will spin off easily so make sure the wave-locks are working properly.

[gchemist]

I have the same problem on my ZZ4 heads. I'm installing short poly locks. You can find them very cheap on ebay.

[SkinnyG]

Here's what I did to replace the press-in studs on my heads. Not something I would want to do ~on~ the engine - pull the heads.

Studs pulled (that was awful - four stripped, and one sheared off).

Holes tapped 7/16 UNC:


Bosses milled 0.400 and counterbored 0.125 (counterboring is not required if using guideplates, but then you need to mill the bosses shorter):


Screw-in studs are screwed in:


These studs require polylocks, and cannot use the factory style lock nut.