I have posted about the engine knock before, most people said it was a leak in the exhaust manifold. I replaced the gaskets and it didn't work. So I pulled off the valve cover today and saw one of the rockers was crooked. I pulled off the rocker and there was damage to the valve stem (i think that is what it is). So what would cause this and how would I fix it?

Please break this down barney style for me because I am very new to this but trying to learn!
Also in my previous posts someone said to pull the valve cover off to determine the brand/model of my aluminum cylinder heads but there are no markings on the inside either. I guess God casted them.

 

I have never seen a rocker arm move sideways before. With not being there in person to look at it. something has too much clearance, if the valve and spring has no play side to side, or the stud that holds down the rocker arm is not loose, I have to believe there is somethin wrong with the lifter (collapsed) meaning the lifter is not as tall as needed due to broken spring no longer has oil in it (lifter), or the cam lob is worn down. I do not know if the valve is repairable with the damage to the top of it. I'm sure some other expert will chime in
Just my 2 cents

 

The head has to come off and the valve and rocker stud and rocker arm replaced.
They can go sideways without pushrod guide plates but you have them.
Is the pushrod guide plate correctly centered on that cylinder?

 

I assume that is the black plate around the push rod? But I don’t know how determine if it is centered other than just looking at it.

 

I find it amazing that the rocker arm could reach all the way over to the side of the retainer. Or did it?
At high RPMs, sometimes the valve spring / retainers will "dance around" clockwise or CCW. That might explain the gash. It was under the rocker arm at one point.

Like wallyfisher said, could be a collapsed lifter, then it recovered. But I would look very closely at the spring. A crack is very difficult to spot sometimes.

First, I would roll the pushrod on a flat surface.
Second, I would put a torque wrench on that rocker stud & check it.
Third I would take a rubber mallet and whack on that valve-spring / retainer. Listen for a unusual sound.

You have your work cut out for you.

 

How long did you continue to drive it after you first heard the noise?
If the rocker arm nut loosened it might permit the rocker to slide sideways
Did the nut look like it wasnt as far down on the stud compared to others?

 

Boy it almost looks like the the rocker twisted ,, this is not the end of the world but the head will have to come off and that valve will have to be replaced and I would no be surprised to see some minimal damage to the top of the piston ,, this happens at high rpm you get valve float cause the springs cant return fast enough and shut the valves down ,, this is a speculation you wont really know untill you take the head off

 

What did the rocker ball look like? That, in itself would allow some lateral movement of the arm.

 

This is probably your problem.
i had those rockers at one point in time and the rocker ball would wear creating slop in the rocker. Enough slop and you get what you have.

my opinion is those rockers are only for low spring pressures. if this is a roller cam your spring pressures are too high and this will continue to happen.

 

This could have been caused by a few things. However, all is fixable. In addition to replacing the rocker arm, valve and stud, I would also replace the push rod as the ball on the end has been compromised. You did not say if the engine has solid lifters or hydraulic. I would replace the lifter too. I would also replace the lock nut on the rocker arm.
Yes, the black thing around the push rod is the guide plate. This keeps the rocker arm aligned properly. More than likely this is not the problem as it is held in place by the rocker arm studs.
This will give you a great learning process and it is not difficult. You will need a few special tools.

 

These are probably what you need. Not sure if you have 3/8" or 7/16" studs there. Probably 3/8" if I had to guess. Take a look at your removed rocker ball, does it still have the oil grooves in it or are they worn down?
https://www.summitracing.com/parts/cca-1401b-16
https://www.summitracing.com/parts/cca-1400b-16



Now the top of that valve looks banged up but it may be salvageable. Kind of depends on how adventurous you are.
The rocker itself looks to be fine and I would bet the pushrod is not bent or damaged either. Roll it on some glass to find out.
Soo, I'll get flamed for this but...you could dress up the top of the valve tip a bit using a dremel and a grinding stone or sanding drum, just so the roller has a flat surface to push on, it doesn't have to be 100% of the top surface of that valve tip just enough for the roller to roll on. It'll require masking off EVERYTHING that you don't want to get sand and metal fragments into. Leaving just the valve tip exposed. Then replace the rocker ball and you'll be back in service, at least in the short term.
Now if you don't or can't get the valve tip surface flat and parallel to the head surface due to too much damage I wouldn't continue. Having a slanted, not flat surface for the rocker tip to roll on is going to create a lot of valve guide wear. That will cost more down the road to repair. Ideally replacing the valve is the correct way to repair this. But that requires quite a lot of time and knowledge which it sounds like you may not have.
Long term you should look at replacing those roller tip rockers with full roller rockers, and pulling the head to replace that valve.
re-installing the roller tip rockers or putting in full roller rockers will require you know how to get the roller acting on the correct width of the valve tip which requires the correct length pushrods. Go to youtube and do a search for roller tip rocker set up and you'll get many videos to choose from like this.
Assuming the current pushrods are of the correct length then the easiest simplest repair is replacing the pivot ball(s). It likely will not be a permanent fix however.

 

Grinding on that valvestem tip would have no effect on installed spring height. However, grinding that down would put the rocker underside just that much closer to the retainer and possibly a interference fit. If someone were to try to salvage that valve, a valve-lash cap would be a better choice. Either way, its bubba repair.

Nothing wrong with Roller-Tip Rockers. Just have to shy away from some of import stuff. They range in price from about $90 to $160.
It does not appear to be Comps, fore they would have their logo near the oil hole. The use of "full roller" rockers will require a different locknut system. Seldom does that fit under a std valve cover.

The trouble with this whole repair is getting parts. I don't believe you can buy just one valve, just one rocker, just one rocker ball, just one retainer or pushrod. I have however, purchased just one lifter and one rocker stud. So, if you end up having to buy eight or sixteen of something, it puts a different perspective on the situation.

 

People who always use the “bubba” term either always had money and or never grew up on a farm or never HAD to keep a motor running until a later time. Lol, bubba is how the job gets finished often until a proper fix can be had.
in either case it’s up to the individual and the situation. Just throwing out an option.

agree that the installed height is not changed, the op has no knowledge of how to properly set up the roller tip rocker that’s why the video.

there are many ways in which to fit full rollers under stock valve covers. My Set up is full roller with stock height valve covers, no clearance issues.

 

I didn't grow up on a farm but we are not talking about an old tractor here. And I didn't always have money either. Did plenty of bubba stuff to be able to get to work.
Pinch off brake lines, coat hanger exhaust, $2 repair plugs shoved in bald tires. These fixes were on old Ford trucks, Pontiacs, Chevys, Olds, etc.

But this is a classic car and I doubt this C3 is a "must fix now" daily driver.

I offered a solution, as did you. Both were not the best solutions.

 

Thanks y'all for your advice. I will have to put the car a for a while because first, I don't have money to get the parts I need if they are in need of replacement and second my schedule picked up a quite a bit and I won't have time to dedicate to a job like this. So for at least a month or two this girl will be down. Thanks again.

 

To me it looks like the guide were never checked for proper clearance. That p-rod looks like it has been rubbing for a while.