Steve Straus

I'm using Harland Sharp roller rockers on my 468, and the engine is running very well now, but one or two of the rockers are just CLACKING.

Is there anything special I need to do with roller rockers to adjust them properly? I took the valve covers off this morning and followed the procedure in the shop manual, but instead of going the full turn after Zero lash, I followed Harland Sharp's instructions and only went 1/2. I couldn't find any clips to use to adjust them while the engine is running, those only seem to be made for stock rocker arms.

Any suggestions? As soon as this sucker stops clicking I can drive it!!!

Thanks!

VETDRMS

From my own experiance and what other people have told me, roller rockers will make a little noise that sounds like they are loose. I was told that the clacking comes from the roller tip moving back and fourth and clacking against the rocker arm casing. This could be wrong, but i've readjusted my set 4 times and it still makes the exact same noise.
:cheers:

Steve Straus

I used a piece of hose and listened, there are definitely a couple that are REALLY loud on the drivers side. THe passenger side sounds pretty quiet. I can hear a little ticking out of some of them, which is noticably different than the two that are just CLACKING. I can hear them over the damn sidepipes.

I'm wondering if I have a collapsed lifter. Damn I hope I haven't lunched this cam...

--
Steve

VETDRMS

Sorry, was gonna put in there that if you can hear it outside the car with the hood shot, its not just normal :smash: :) I've been told it can be two things, a collapsed lifter, or a flattened lobe would have the same effect. Sorry i can't be of much more help, hope somebody who can be will chime in soon! :cheers:

MotorHead

Don't freak out yet, I had a mojor problem with my rockers making noise and it took me a month to figure it out, finally found out the pushrods were wearing down because the metal was not compatible with the rockers. Put in some CC Magnum pushrods and haven't had a problem since.

You should really try to adjust them with engine running, besides the slight noise that is inherent with roller rockers you should be able to remove any ticking that a lash problem wll cause.

I am not sure about how bad the oil sprays around under big block covers but you might want to cut a slot in a old valve cover to help reduce any mess. :D

Steve Straus

How did you finally determine this? This engine has maybe 30 minutes of running time on it total.

Cutting a straight line in a valve cover like that works for small blocks, but you'd have to get creative with this setup. Notice that not only are the valves offset, but they're canted as well. I don't know of anyone that makes clips for roller rockers.





--
Steve

73 LS-4

My suggestion before making a large mess would be to pull the valve covers and turn it over by hand and watch for any rocker arms with excessive play and then readjust those rocker arms, also double check to make sure that none of your locks backed off. I had one rocker arm do this to me, guess I didn't get it tight enough :confused: , fortunately I caught it while I was just out cruising, if it got that loose at high RPM I might of had a real problem :eek:

:cheers:
Pat Kunz

Steve Straus

Would I be able to see this turning it over by hand? I hear ya on the locks backing off, I tightened them this morning and it didn't seem to help..hmm..

--
Steve

Chuck Harmon

Steve,

I adjust my valves with the engine warmed up, but off. I find the highest lift point of a valve and then rotate the engine one complete turn, by using a long handled ratchet wrench on the crank pully nut. I set the 8 intake valves, and then do the exhaust valves (or visa versa). I proceed to set each valve in firing order by rotating the engine 90 degrees at the crank using the wrench to advance the engine.

Just to be sure, I usually re-check the last valve, and/or what should be the next one with the same feeler gauge just to make sure all is in order. If the gauge has more clearance at the such points, something is wrong.

You can calculate where this should be if you don't have a dial indicator and base if you know the precise opeing and closing points of the cam in crank degrees. But aren't you running a solid cam? Your instructions sound like setting zero lash for hydraulic.

Chuck



[Modified by Chuck Harmon, 11:50 PM 9/29/2002]

Steve Straus

They're Hydraulic.

Fevre

Did a similar thing but cut the cover in the shape of a 'U' so I could bend the cut piece out towards the fender and it acts like a splash guard. The deflector clips didn't work well with my roller rockers so the valve cover 'lip' I cut helped catch the oil.

BTW Mine clack a little too. I had one rocker nut come loose and when that happens you can tell the diff from that clanking and the normal clacking/ticking.


[Modified by Fevre, 9:10 AM 9/30/2002]

Chuck Harmon

I am even more impressed with your engine's abilities. Look forward to seeing a chassis dyno test sometime once you get everythng sorted out.

Chuck

gkull

Back when I had H-flat cams and roller tips or full roller rockers I set them very much like I do my solid rollers.

Warm up the motor and shut it off. I would use the book cylinder order of adjustment. I would place the .020 feel gauge under the roller tip and crank the nut down till It was just a a little hard to pull the feeler gauge out. I never heard of so many flat cams, bent push rods, or torn up tips until I got on this forum. I would put 10,000+ bad miles on a motor a year on H-flat cams without a problem.

All that mess of adjusting while the motor is running or that static cranking down to zero lash and doing more or less additional turns is so inaccurate and iffy. Two expert mechanics could adjust the same car and make it 10-15 thousands different. :eek:

The feeler gauge is always the same :seeya

73 LS-4

Sometimes you can see the play just by turning a bit by hand and checking over the rockers that quit moving as you turn, it is time consuming to do this but I have found play by this method more then once on different engines. As others have suggested it's normally better to do this just after you ran the engine so there is some oil left in the lifters although it tends to bleed off quick as soon as a valve tries to open and the spring pressure works against the lifter. Also pull the plugs before trying to turn it by hand it makes it a whole lot easier for sure. Can you isolate a side by listening through a breather hole or PCV grommet? Obviously the best way is to adjust while the engine is running, but if you can find the problem this way is saves some mess.

:cheers:
Pat Kunz

Pete79L82

Steve:

Some aftermarket valve cover have thicker walls. When used with a large body roller rocker the rocker will hit the top of the valve cover (along the intake side of the valve cover) Look real close at the cover to make sure that this is not where your noise is coming from. If this is the problem you should see some marks on the cover inline with the 4 intake rockers on that bank.


[Modified by Pete79L82, 3:43 PM 9/30/2002]

Steve Straus

I like the way you think. I'll give this a try.

Cheers!

--
Steve

vettfixr

There's a good possibility that the problem is in the studs and not the rockers. If the studs aren't perfectly flat on the top the poly locks won't tighten correctly and will cause the rocker to loosen. You might want to see which one's are making noise using the hose trick and once you've located them take a look at the top of the studs. ARP makes good studs that work well with roller rockers.

Steve Straus

I'm going to go pull it apart in a few minutes. It already has ARP studs.

--
Steve

jdunne

Steve,are you sure it isnt a prob with the lifter?...one of my new crane lifters had an intermittent prob in the inner piston in the lifter was slightly out of round and would sometimes bind part way.....where this showed was in the cup on the underside of the rocker,the wear was outside the center of the cup.....at first i thought i had bent a pushrod so i first checked all o them.....the noise was very obviously confined to one rocker but i checked them all......this was a brand new lifter that failed in less than 1000 miles but worked fine when first installed.....when we measured the piston it was about .002 out of round and the prob really only showed up when very hot......john :chevy ;)

Clink69

Steve,

Is there any possibility that these types of issues could be looked at by your engine builder for nothing. My engine had different , but problems none the less and I took it back to them several times until they made it right. Just a thought.

Chris

:flag