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rocker arms problem

  
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rocker arms problem

 
praza praza
New User | Posts: 3 | Joined: 06/13
Posted: 06/19/13
09:01 AM

I have a problem with my 87 caprice. I torn apart the engine, and IMHO I found something unusual. The side aligment of rocker arms have a huge side allowance. The rocker arms are moving from side to side, even using just using just pushrods, although they were adjusted. One side of the engine is better then other.

I feel the new rocker arm kit is a solution, but what could cause this behavior and what allows it?

Please check videos below


http://youtu.be/dtC6nn5r7AE

http://youtu.be/ryPulDjh2hc  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 06/19/13
09:21 AM

Roller motors use self-aligning rockers that you either do not have or are not adjusted tight enough.  
68scott385 68scott385 68scott385

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 06/19/13
09:24 AM

http://paceperformance.com/i-6497436-pac-12495490-gm-stamped-steel-1-5-ratio-self-aligning-rocker-arm-kit-set-of-16-new-take-offs.html

This page has a good picture of the rocker tips and shows the troughed valve tip end. If yours do not look like these at the valve tip end, you need to replace them.  
68scott385 68scott385 68scott385

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 06/19/13
04:31 PM

i agree with Scott, you need self-aligning rocker arms.

  heres a link to some self-aligning arms.   see how theres a small washer on each side of the roller tip?   that will stop the side to side movement.

  http://www.jegs.com/i/Proform/778/66914/10002/-1  

shaggin_wagon shaggin_wagon
New User | Posts: 9 | Joined: 06/13
Posted: 06/20/13
01:54 PM

+1 on the new rocker setup. Also, not sure if this will apply to your setup or not, but I had a customer come to me wanting a valve adjustment done on his pushrod 5.0. The rockers were making a lot of top end noise. So I took it apart thinking it would be a typical adjustment which isn't a hard task by any means. Turns out he had a none adjustable rocker kit which he informed me beforehand that they were adjustable and that was not the case. What the problem actually was turned out to be the pushrods were not the correct length. They swapped heads, cam, rockers all the valve train when building the motor, but they used factory pushrods which turned out to be too short causing side to side and up and down play on the rocker and pushrod. Maybe your pushrods could be the wrong length?  

tuffnuff tuffnuff
Moderator | Posts: 7828 | Joined: 12/09
Posted: 06/20/13
02:57 PM

Buyer beware.,.

Known and or suspected Chinese rockers

PRW
PROCOMP
PROFORM
ARC mfg by Assault Racing sold by KMJ Performance
COMP CAMS “ALUMINUM” series, likely made in India
COMP CAMS “HIGH ENERGY” series, die cast aluminum, likely made in India
SUNGLORY Direct from China. Read their ad below.

Sunglory aluminum rocker arms feature colorful charming appearance owing to the anodized treatment to resist weariness.

Machined from the high quality extruded aluminum alloy, using state-of-the-art extrusion processing to ensure the superior flow of the aluminum grain for optimum wear resistance, our rockers are provided in 1.5, 1.6 and 1.7 ratios.

The needle bearing machined (instead of stamped)offer the advantage of high strengthand smooth operation. Roller tips are heat-treated too for superior durability. Polylocks are provided.

Sunglory aluminum rocker arms are the best choice for racers at an affordable cost.

http://www.sungloryparts.com/showproduct.asp?id=121

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

skyeking skyeking
Addict | Posts: 2738 | Joined: 08/09
Posted: 06/20/13
05:29 PM

Hi Agent 69,
 Howzit goink with you??.  
skyeking

praza praza
New User | Posts: 3 | Joined: 06/13
Posted: 06/22/13
06:45 AM

Thank you everyone for your feedback.

For the reference, this is suppost to be stock GM engine in 87 Caprice, which I own for about 5 years. Its now my weekend car, but as dd it servers me about 20k miles up to total around 150k miles.

Back to the problem:
Rocker arms clearance on one side of the engine is greater than the other one. The posted video was taken after careful adjustment of both sides.

Pushrods of some valves even lean on the wall in the cylinder head hole, which I do not like to see.

Today I checked everything carefully, the length and diameter of all pushrods are identical.I changed rocker arms of the "good" side and put them on the "wrong" side and vice versa. This does not changed anything, the allowance on the one side of cylinders is larger, then other side.
Therefore the reason is not rocker arms.

After closer examination I have discovered a mystery.
The "good" head have in the holes for the pushrods guide tabs on the sides.
The "bad" head have a circular holes and side allowance is therefore greater.

Both heads have the same part number, but 1 was in past exchanged for replacement part from 88 Caprice due the cracked head.

Excessive lateral allowance of the rockers would be diminished, if I install the pushrods with a larger diameter. Do you know if there are pushrods with different diameters?

I disassembled the engine for several oil seal leaks and also, when the engine was running, I was able to hear irregular knocking of timing chain. Therefore I wanted to check the rocker arms.

Now I wonder, if its worth to deal with this large laterel allowance, or not.

I appriciate the time you are spending reading and thinking about my problems, thank you  Wink

Rockerarms  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 06/22/13
08:51 AM

Those rocker arms in the picture are the wrong rocker arms for that motor. In the posted videos we can see that there is a spider-spring to hold the factory roller lifter dogbones in place, factory roller motors must use self-aligning rocker arms.

At least two of us have posted links to the correct style rocker arms.  
68scott385 68scott385 68scott385

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 06/22/13
08:53 AM

why not just get the right rockers arms?    problem solved!     they're probably the next best thing to guideplates?    
   unless,...your setting the valves way too loose?
 but being a roller motor, you should be running self-aligning rockers, IMO.  

tuffnuff tuffnuff
Moderator | Posts: 7828 | Joined: 12/09
Posted: 06/22/13
09:14 AM

+! guys,
Rail rockers would solve the problem.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

tuffnuff tuffnuff
Moderator | Posts: 7828 | Joined: 12/09
Posted: 06/22/13
09:14 AM

+! guys,
Rail rockers would solve the problem.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

praza praza
New User | Posts: 3 | Joined: 06/13
Posted: 07/01/13
12:48 PM

Thanks everyone for help, my new correct set of rocker arms just arrived to custom clerance in my country. Will post the result soon Wink